Common cold

Definition

The common cold is a viral infection of the upper respiratory system, which includes the nose, throat, sinuses, eustachian tubes, trachea, larynx, and bronchial tubes. Although more than 200 different viruses can cause a cold, 30–50% are caused by a group known as rhinoviruses. Almost all colds clear up in less than two weeks without complications.

Description

Colds, sometimes called rhinovirus or coronavirus infections , are the most common illness to strike any part of the body. It is estimated that the average person has more than 50 colds during a lifetime. Anyone can get a cold, although preschool and grade school children catch them more frequently than adolescents and adults. Repeated exposure to viruses causing colds creates partial immunity.

Although most colds resolve on their own without complications, they are a leading cause of visits to the doctor and of time lost from work and school. Treating symptoms of the common cold has given rise to a multimillion dollar industry in over-the-counter medications, yet none of these medications are actually anti-viral to the rhinovirus.

Cold season in the United States begins in early autumn and extends through early spring. Although it is not true that getting wet or being in a draft causes a cold (a person has to come in contact with the virus to catch a cold), certain conditions may lead to increased susceptibility. These include:

• fatigue and overwork
• emotional stress
• poor nutrition
• smoking
• inadequate rest or sleep
• living or working in crowded conditions

Colds make the upper respiratory system less resistant to secondary bacterial infection. Secondary bacterial infection may lead to a number of other complications, including middle ear infection, bronchitis, pneumonia, sinus infection , or strep throat . People with chronic lung disease, asthma , diabetes, or a weakened immune system are more likely to develop these complications.

Causes & symptoms

Colds are caused by more than 200 different viruses. The most common groups include rhinoviruses and coronaviruses. Different groups of viruses are more infectious at different seasons of the year, but knowing the exact virus causing the cold is not important in treatment.

People with colds are contagious during the first two to four days of the onset of symptoms. Colds pass from person to person in several ways. When an infected person coughs, sneezes, or speaks, tiny fluid droplets containing the virus are expelled. If these are breathed in by other people, the virus may establish itself in their noses and airways.

Colds may also be passed through direct contact. For example, if a person with a cold touches his runny nose or watery eyes, then shakes hands with another person, some of the virus is transferred to the uninfected person. If that person then touches his mouth, nose, or eyes, the virus is transferred to an environment where it can reproduce and cause a cold.

Finally, cold viruses can be spread through inanimate objects (door knobs, telephones, toys) that become contaminated with the virus. This is a common method of transmission in child care centers. Another vector of transmission is air travel, due to closed air circulation in buildings.

Once acquired, the cold virus attaches itself to the lining of the nasal passages and sinuses. This causes the infected cells to release a chemical called histamine. Histamine increases the blood flow to the infected cells, causing swelling, congestion, and increased mucus production. Within one to three days, the infected person begins to show cold symptoms.

The first cold symptoms are usually a tickle in the throat, runny nose, and sneezing . The initial discharge from the nose is clear and thin. Later, it may change to a thick yellow or greenish discharge. Most adults do not develop a fever when they catch a cold. Young children may develop a low fever of up to 102°F (38.9°C).

Other symptoms of a cold include coughing, sneezing, nasal congestion, headache , muscle ache, chills, sore throat , hoarseness, watery eyes, fatigue, dull hearing and blocked eustachian tube (a danger when flying), and lack of appetite. The cough that accompanies a cold is usually intermittent and dry.

Most people begin to feel better four to five days after their cold symptoms become noticeable. All symptoms are generally gone within 10 days, except for a dry cough that may linger for up to three weeks.

Colds make people more susceptible to secondary bacterial infections such as strep throat, middle ear infections, and sinus infections. A person should seek a doctor's consultation if the cold does not begin to improve within a week. If an individual experiences chest pain , fever for more than a few days, difficulty breathing, bluish lips or fingernails, a cough that brings up greenish-yellow or grayish sputum, skin rash, swollen glands, or whitish spots on the tonsils or throat, then that person should also consult a doctor to see if they have acquired a secondary bacterial infection that needs to be treated with an antibiotic.

People who have emphysema , chronic lung disease, diabetes, or a weakened immune system—either from diseases such as AIDS or leukemia , or as the result of medications, (corticosteroids, chemotherapy drugs)—should consult their doctor if they get a cold. People with these health problems are more likely to get a secondary infection.

Diagnosis

Colds are diagnosed by observing a person's symptoms and symptom history. There are no laboratory tests readily available to detect the cold virus. However, a doctor may do a throat or nasal culture, or blood test to rule out a secondary infection.

Influenza is sometimes confused with a cold, but the flu causes much more severe symptoms, and is generally accompanied by a fever. Allergies to molds or pollens also can cause a runny nose and eyes. Allergies are usually more persistent than the common cold. An allergist

or a physician can do tests to determine if the cold-like symptoms are being caused by an allergic reaction. Also, some people get a runny nose when they go out-side in winter and breathe cold air. This type of runny nose, however, is not a symptom of a cold.

Treatment

The patient should drink plenty of fluids and eat nutritious foods. In fact, the old adage, "Feed a cold, starve a fever" was scientifically proven true in 2002. Dutch scientists found that cold-fighting immune responses rose after consuming a full meal while fasting increased those that combat most fevers. Chicken soup with ginger , scallions, and rice noodles is nutritious and has properties that help the patient to recover. Rest, to allow the body to fight infection, is very important. Gargling with saltwater (half teaspoon salt in one cup of water) helps to soothe a sore throat. A vaporizer also will make the patient feel more comfortable. Rubbing petroleum jelly or some other lubricant under the nose will prevent irritation from frequent nose blowing. For babies, nasal mucus should be suctioned gently with an infant nasal aspirator. It may be necessary to soften the mucus first with a few drops of salt water.

Herbals

Herbals can be taken to stimulate the immune system, for antiviral activity, and to relieve symptoms. The following herbs are used to treat colds:

• Ginger (Zingiber officinale ) reduces fever and pain, has a sedative effect, settles the stomach, and suppresses cough.
• Forsythia (Forsythia suspensa ) fruit can be taken as a tea for its anti-inflammatory, fever reducing, and antimicrobial properties.
• Honeysuckle (Lonicera japonica ) flower can be taken as a tea for its anti-inflammatory, fever reducing, and antimicrobial properties.
• Aniseed (Pimpinella anisum ) can be added to tea to expel phlegm, induce sweating, ease nausea , and ease stomach gas.
• Slippery elm powdered bark (Ulmus fulva ) can be taken as a tea or slurry or capsules to soothe sore throat, to ease cough, and to thin mucous.
• Echinacea (Echinacea purpurea or augustifolia ) relieved cold symptoms in clinical studies. The usual dosage is 500 mg of crude powdered root or plant thrice on the first day, then 250 mg four times daily thereafter. This may also be taken as a tincture.
• Goldenseal (Hydrastis canadensis ) has fever reducing, antibacterial, anti-inflammatory, and antitussive properties. The usual dose is 125 mg three to four times daily. Goldenseal should not be taken for more than one week. Goldenseal may also be prepared as a tincture.
• Astragalus (Astragalus membranaceus ) boosts the immune system and improves the body's response to stress. The common dose is 250 mg of extract four times daily.
• Cordyceps (Cordyceps sinensis ) modulates and boosts the immune system and improves respiration. The usual dose is 500 mg two to three times daily.
• Elder (Sambucus ) has antiviral activity, increases sweating, decreases inflammation, and decreases nasal discharge. The usual dose is 500 mg of extract thrice daily.
• Stinging nettle (Urtica dioica ) has antihistamine and anti-inflammatory properties. The common dose is 300 mg four times daily.
• Schisandra (Schisandra chinensis ) helps the body fight disease and increases endurance.
• Grape (Vitis vinifera ) seed extract has antihistamine and anti-inflammatory properties. The usual dose is 50 mg three times daily.
• Eucalyptus (Eucalyptus globulus ) or peppermint (Mentha piperita ) essential oils added to a steam vaporizer may help clear chest and nasal congestion and disinfect room air.
• Boneset infusion (Eupatroium perfoliatum ) relieves aches and fever.
• Yarrow (Achillea millefolium ) is a diaphoretic.
• Supplemental larch from the inner bark of the western larch tree has been shown in some clinical trials to fight persistent colds and ear aches.

Chinese medicines

Chinese herbal treatments are based on the specific symptoms of colds and include a variety of Radix, Rhizoma, Semen, and Herba species. Chinese patent medicines for cold include:

• Wu Shi Cha (Noon tea): once or twice daily.
• Yin Qiao Jie Du Pian (Honeysuckle and Forsythia Tablet to Overcome Toxins): four to six, twice daily.
• Sang Ju Gan Mao (Mulberry Leaf and Chrysanthemum to Treat Common Cold): one packet of infusion or four to eight tablets, twice or thrice daily.
• Ling Yang Gan Mao Pian (Atelopis Tablet for Common Cold): four to six, twice daily.
• Ban Lan Gen Chong Ji (Isatidis Infusion): one packet twice or thrice daily.
• Huo Xiang Zheng Qi (Agastache to Rectify Qi): 6 g or four to six tablets.

Other remedies

The effectiveness of zinc lozenges for preventing or treating the common cold is controversial. Numerous studies have generated contradicting results. It has been suggested that the citric acid, sorbitol, or mannitol in some lozenges may bind zinc and reduce effectiveness, hence the varying results of these studies. The recommended dosage is to suck on one lozenge every two hours while awake beginning at the first cold symptoms. Side effects are bad taste, nausea, and vomiting .

Ayurvedic medicine practitioners recommend gargling with a mixture of water, salt, and turmeric powder or astringents such as alum, sumac, sage , and bayberry to ease a sore throat.

Homeopaths recommend microdoses of Viscue album, Natrum muriaticum, Allium cepa, or Nux vomica.

Allopathic treatment

There are no known medicines proven to shorten or cure the common cold. Antibiotics are useless against a cold, and can enhance bacterial resistance, if used carelessly. Nonprescription products to relieve cold symptoms usually contain antihistamines, decongestants, and/or pain relievers. Over-the-counter cold remedies should not be given to infants without consulting a doctor first. Care should be taken not to exceed the recommended dosages, especially when combination medications or nasal sprays are taken. Aspirin should not be given to children with a cold because of its association with a risk of Reye's syndrome, a serious disease.

Antihistamines are taken to relieve the symptoms of sneezing, runny nose, itchy eyes, and congestion. Side effects are dry mouth and drowsiness, especially with the first few doses. Some people have allergic reactions to antihistamines. Common over-the-counter antihistamines include Chlor-Trimeton, Dimetapp, Tavist, and Actifed. The generic name for two common antihistamines are chlorpheniramine and diphenhydramine.

Decongestants reduce congestion and open inflamed nasal passages, making breathing easier. Decongestants can make people feel jittery or keep them from sleeping. They should not be used by people with heart disease , high blood pressure, or glaucoma . Some common decongestants are Neo-Synepherine, Novafed, and Sudafed. The generic names of common decongestants include phenylephrine, phenylpropanolamine, pseudoephedrine, and in nasal sprays naphazoline, oxymetazoline, and xylometazoline. Nasal sprays and nose drop decongestants can act more quickly and strongly than ones found in pills or liquids because they are applied directly in the nose. Congestion returns after a few hours. Persons can become dependent on nasal sprays and nose drops, so they should not be used for more than a few days.

Many over-the-counter medications are combinations of both antihistamines and decongestants; an ache and pain reliever, such as acetaminophen (Datril, Tylenol, Panadol) or ibuprofen (Advil, Nuprin, Motrin, Medipren); and a cough suppressant (dextromethorphan). Common combination medications include Tylenol Cold and Flu, Triaminic, Sudafed Plus, and Tavist D.

Expected results

Given time, the body will make antibodies to cure itself of a cold. Most colds last seven to 10 days. Most people start feeling better within four or five days. Occasionally, a cold will lead to a secondary bacterial infection that causes strep throat, bronchitis, pneumonia, sinus infection, or a middle ear infection.

Prevention

Prevention focuses on strengthening the immune system by eating a healthy diet low in sugars and high in fresh fruits and vegetables, practicing meditation to reduce stress, getting adequate sleep, and getting regular moderate exercise . Some steps persons can take to prevent catching a cold and to reduce their spread include:

• washing hands well and frequently
• covering the mouth and nose when sneezing
• avoiding close contact with someone who has a cold during the first two to four days of their infection
• not sharing food, eating utensils, or cups
• avoiding crowded places where cold viruses can spread
• keeping hands away from the face
• avoiding cigarette smoke
• taking Echinacea; 250 mg up to four times daily for three weeks on, one week off
• taking astragalus; 250 mg to 500 mg daily.
• taking a multivitamin with zinc
• taking vitamin C ; 500 mg
• taking Anas barbariae hepatis ; one dose weekly

In 2002, researchers discovered that transmission of the rhinovirus may be prevented through the use of anti-septic skin cleansers containing salicylic acid or pyroglutamic acid. The cleansers have properties that can kill the viruses and help prevent hand-to-hand transmission, but further research on their effectiveness remains to be done.

Resources

BOOKS

Castleman, Michael. "Cold and Flu Therapy." In Nature's Cures. Emmaus, PA: Rodale Press, 1996.

Silverstein Alvin, et al. Common Cold and Flu (Diseases and People). Springfield, MA: Enslow Publishers, 1996.

Ying, Zhou Zhong, and Jin Hui De. "Exterior Invasion." In Clinical Manual of Chinese Herbal Medicine and Acupuncture. New York: Churchill Livingston, 1997.

PERIODICALS

"Antispetic Skin Cleansers May Prevent Rhinovirus Transmission."Clinical Infectious Diseases (February 1, 2002): ii.

Bourassa, Nicole. "Larch: This Immune Booster Fights Tenacious Colds and Ear Infections."Natural Health (March 2002): 35.

Elkins, Rita. "Combat Colds and Flu."Let's Live 68 (January 2000): 81+.

Jackson, Jeffrey L., Cecily Peterson, and Emil Lesho. "A Meta-Analysis of Zinc Salts Lozenges and the Common Cold." Archives of Internal Medicine 157 (1997): 2373–2376.

Le Page, Michael. "Eat to Treat: The Maxim "Feed a Cold, Starve a Fever" May be Right After All."New Scientist (January 19, 2002): 15.

Marshall, Shaun. "Zinc Gluconate and the Common Cold: Review of Randomized Controlled Trials."Canadian Family Physician 44 (1998): 1037–1042.

Mayo Health Clinic. "Zinc: A Weapon Against the Common Cold?"Mayo Health Oasis http://www.mayohealth.org/mayo/9709/htm/zinc.htm. (9 September 1997).

Belinda Rowland

Teresa G. Odle

Common Cold

Definition

The common cold is a viral infection of the upper respiratory system, including the nose, throat, sinuses, eustachian tubes, trachea, larynx, and bronchial tubes. Although more than 200 different viruses can cause a cold, 30-50% are caused by a group known as rhinoviruses. Almost all colds clear up in less than two weeks without complications.

Description

Colds, sometimes called rhinovirus or coronavirus infections, are the most common illness to strike any part of the body. It is estimated that the average person has more than 50 colds during a lifetime. Anyone can get a cold, although pre-school and grade school children catch them more frequently than adolescents and adults. Repeated exposure to viruses causing colds creates partial immunity.

Although most colds resolve on their own without complications, they are a leading cause of visits to the doctor and of time lost from work and school. Treating symptoms of the common cold has given rise to a multi-million dollar industry in over-the-counter medications.

Cold season in the United States begins in early autumn and extends through early spring. Although it is not true that getting wet or being in a draft causes a cold (a person has to come in contact with the virus to catch a cold), certain conditions may lead to increased susceptibility. These include:

• fatigue and overwork
• emotional stress
• poor nutrition
• smoking
• living or working in crowded conditions

Colds make the upper respiratory system less resistant to bacterial infection. Secondary bacterial infection may lead to middle ear infection, bronchitis, pneumonia, sinus infection, or strep throat. People with chronic lung disease, asthma, diabetes, or a weakened immune system are more likely to develop these complications.

Causes and symptoms

Colds are caused by more than 200 different viruses. The most common groups are rhinoviruses and coronaviruses. Different groups of viruses are more infectious at different seasons of the year, but knowing the exact virus causing the cold is not important in treatment.

People with colds are contagious during the first two to four days of the infection. Colds pass from person to person in several ways. When an infected person coughs, sneezes, or speaks, tiny fluid droplets containing the virus are expelled. If these are breathed in by other people, the virus may establish itself in their noses and airways.

Colds may also be passed through direct contact. If a person with a cold touches his runny nose or watery eyes, then shakes hands with another person some of the virus is transferred to the uninfected person. If that person then touches his mouth, nose, or eyes, the virus is transferred to an environment where it can reproduce and cause a cold.

Finally, cold viruses can be spread through inanimate objects (door knobs, telephones, toys) that become contaminated with the virus. This is a common method of transmission in child care centers. If a child with a cold touches her runny nose, then plays with a toy, some of the virus may be transferred to the toy. When another child plays with the toy a short time later, he may pick up some of the virus on his hands. The second child then touches his contaminated hands to his eyes, nose, or mouth and transfers some of the cold virus to himself.

Once acquired, the cold virus attaches itself to the lining of the nasal passages and sinuses. This causes the infected cells to release a chemical called histamine. Histamine increases the blood flow to the infected cells, causing swelling, congestion, and increased mucus production. Within one to three days the infected person begins to show cold symptoms.

The first cold symptoms are a tickle in the throat, runny nose, and sneezing. The initial discharge from the nose is clear and thin. Later it changes to a thick yellow or greenish discharge. Most adults do not develop a fever when they catch a cold. Young children may develop a low fever of up to 102°F (38.9°C).

In addition to a runny nose and fever, signs of a cold include coughing, sneezing, nasal congestion, headache, muscle ache, chills, sore throat, hoarseness, watery eyes, tiredness, and lack of appetite. The cough that accompanies a cold is usually intermittent and dry.

Most people begin to feel better four to five days after their cold symptoms become noticeable. All symptoms are generally gone within ten days, except for a dry cough that may linger for up to three weeks.

Colds make people more susceptible to bacterial infections such as strep throat, middle ear infections, and sinus infections. A person whose cold does not begin to improve within a week; or who experiences chest pain, fever for more than a few days, difficulty breathing, bluish lips or fingernails, a cough that brings up greenish-yellow or grayish sputum, skin rash, swollen glands, or whitish spots on the tonsils or throat should consult a doctor to see if he or she has acquired a secondary bacterial infection that needs to be treated with an antibiotic.

People who have emphysema, chronic lung disease, diabetes, or a weakened immune system—either from diseases such as AIDS or leukemia, or as the result of medications, (corticosteroids, chemotherapy drugs)—should consult their doctor if they get a cold. People with these health problems are more likely to get a secondary infection.

Diagnosis

Colds are diagnosed by observing a person's symptoms. There are no laboratory tests readily available to detect the cold virus. However, a doctor may do a throat culture or blood test to rule out a secondary infection.

Influenza is sometimes confused with a cold, but flu causes much more severe symptoms and generally a fever. Allergies to molds or pollens also can make the nose run. Allergies are usually more persistent than the common cold. An allergist can do tests to determine if the cold-like symptoms are being caused by an allergic reaction. Also, some people get a runny nose when they go outside in winter and breathe cold air. This type of runny nose is not a symptom of a cold.

Treatment

There are no medicines that will cure the common cold. Given time, the body's immune system will make antibodies to fight the infection, and the cold will be resolved without any intervention. Antibiotics are useless against a cold. However, a great deal of money is spent by pharmaceutical companies in the United States promoting products designed to relieve cold symptoms. These products usually contain antihistamines, decongestants, and/or pain relievers.

Antihistamines block the action of the chemical histamine that is produced when the cold virus invades the cells lining the nasal passages. Histamine increases blood flow and causes the cells to swell. Antihistamines are taken to relieve the symptoms of sneezing, runny nose, itchy eyes, and congestion. Side effects are dry mouth and drowsiness, especially with the first few doses. Antihistamines should not be taken by people who are driving or operating dangerous equipment. Some people have allergic reactions to antihistamines. Common over-the-counter antihistamines include Chlor-Trimeton, Dimetapp, Tavist, and Actifed. The generic name for two common antihistamines are chlorpheniramine and diphenhydramine.

Decongestants work to constrict the blood flow to the vessels in the nose. This can shrink the tissue, reduce congestion, and open inflamed nasal passages, making breathing easier. Decongestants can make people feel jittery or keep them from sleeping. They should not be used by people with heart disease, high blood pressure, or glaucoma. Some common decongestants are Neo-Synepherine, Novafed, and Sudafed. The generic names of common decongestants include phenylephrine, phenylpropanolamine, pseudoephedrine, and in nasal sprays naphazoline, oxymetazoline and xylometazoline.

Many over-the-counter medications are combinations of both antihistamines and decongestants; an ache and pain reliever, such as acetaminophen (Datril, Tylenol, Panadol) or ibuprofen (Advil, Nuprin, Motrin, Medipren); and a cough suppressant (dextromethorphan). Common combination medications include Tylenol Cold and Flu, Triaminic, Sudafed Plus, and Tavist D. Aspirin should not be given to children with a cold because of its association with a risk of Reye's syndrome, a serious disease.

Nasal sprays and nose drops are other products promoted for reducing nasal congestion. These usually contain a decongestant, but the decongestant can act more quickly and strongly than ones found in pills or liquids because it is applied directly in the nose. Congestion returns after a few hours.

People can become dependent on nasal sprays and nose drops. If used for a long time, users may suffer withdrawal symptoms when these products are discontinued. Nasal sprays and nose drops should not be used for more than a few days. The label lists recommendations on length and frequency of use.

Scientists reported in 2004 the possibility of a new oral drug for use in relieving common cold symptoms. Called pleconaril, it inhibited viral replication in at least 90% of rhinoviruses if taken within 24 hours of onset.

People react differently to different cold medications and may find some more helpful than others. A medication may be effective initially, then lose some of its effectiveness. Children sometimes react differently than adults. Over-the-counter cold remedies should not be given to infants without consulting a doctor first.

Care should be taken not to exceed the recommended dosages, especially when combination medications or nasal sprays are taken. Individuals should determine whether they wish to use any of these drugs. None of them shorten or cure a cold. At best they help a person feel more comfortable. People who are confused about the drugs in any over-the-counter cold remedies should ask their pharmacist for an explanation.

In addition to the optional use of over the counter cold remedies, there are some self-care steps that people can take to ease their discomfort. These include:

• drinking plenty of fluids, but avoiding acidic juices, which may irritate the throat
• gargling with warm salt water—made by adding one teaspoon of salt to 8 oz of water—for a sore throat
• not smoking
• getting plenty of rest
• using a cool-mist room humidifier to ease congestion and sore throat
• rubbing Vaseline or other lubricant under the nose to prevent irritation from frequent nose blowing
• for babies too young to blow their noses, the mucus should be suctioned gently with an infant nasal aspirator. It may be necessary to soften the mucus first with a few drops of salt water.

Alternative treatment

Alternative practitioners emphasize that people get colds because their immune systems are weak. They point out that everyone is exposed to cold viruses, but not everyone gets every cold. The difference seems to be in the ability of the immune system to fight infection. Prevention focuses on strengthening the immune system by eating a healthy diet low in sugars and high in fresh fruits and vegetables, practicing meditation to reduce stress, and getting regular moderate exercise.

Once cold symptoms appear, some naturopathic practitioners believe the symptoms should be allowed to run their course without interference. Others suggest the following:

• Inhaling a steaming mixture of lemon oil, thyme oil, eucalyptus, and tea tree oil (Melaleuca spp.). (Aromatherapy )
• Gargling with a mixture of water, salt, and turmeric powder or astringents such as alum, sumac, sage, and bayberry to ease a sore throat. (Ayurvedic medicine )
• Taking coneflower or goldenseal (Hydrastis canadensis ). Other useful herbs to reduce symptoms include yarrow (Achillea millefolium ), eyebright (Euphrasia officinalis ), garlic (Allium sativum ), and onions (Allium cepa ). (Herbal)
• Microdoses of Viscue album, Natrum muriaticum, Allium cepa, or Nux vomica. (Homeopathy)
• Taking yin chiao (sometimes transliterated as yinquiao) tablets that contain honeysuckle and forsythia when symptoms appear. Natural herb loquat syrup for cough and sinus congestion and Chinese ephedra (ma-huang ) for runny nose. (Chinese traditional medicine)
• The use of zinc lozenges every two hours along with high doses of vitamin C is suggested. Some practitioners also suggest eliminating dairy products for the duration of the cold. (Nutritional therapy).

The use of zinc lozenges may be moving toward acceptance by practitioners of traditional medicine. In 1996 the Cleveland Clinic tested zinc gluconate lozenges and found using zinc in the first 24 hours after cold symptoms occurred shortened the duration of symptoms. The mechanism by which zinc worked was not clear, but additional studies are underway.

At one time, the herb (Echinacea spp.) was touted as a remedy to relieve cold symptoms. However, a study published in 2004 reported that the herb failed to relieve cold symptoms in 400 children taking it and caused skin rashes in some children.

Prognosis

Given time, the body will make antibodies to cure itself of a cold. Most colds last a week to 10 days. Most people start feeling better within four or five days. Occasionally a cold will lead to a secondary bacterial infection that causes strep throat, bronchitis, pneumonia, sinus infection, or a middle ear infection. These conditions usually clear up rapidly when treated with an antibiotic.

Prevention

It is not possible to prevent colds because the viruses that cause colds are common and highly infectious. However, there are some steps individuals can take to reduce their spread. These include:

• washing hands well and frequently, especially after touching the nose or before handling food
• covering the mouth and nose when sneezing
• disposing of used tissues properly

• avoiding close contact with someone who has a cold during the first two to four days of their infection
• not sharing food, eating utensils, or cups with anyone
• avoiding crowded places where cold germs can spread
• eating a healthy diet and getting adequate sleep

Resources

PERIODICALS

"Study: Echinacea Is Ineffective." Chain Drug Review February 16, 2004: 25.

Zepf, Bill. "Pleconaril for Treatment of the Common Cold?" American Family Physician February 1, 2004: 703.

KEY TERMS

Bronchial tubes— The major airways to the lungs and their main branches.

Coronavirus— a genus of viruses that cause respiratory disease and gastroenteritis.

Corticosteroids— A group of hormones produced naturally by the adrenal gland or manufactured synthetically. They are often used to treat inflammation. Examples include cortisone and prednisone.

Eustachian tube— A thin tube between the middle ear and the pharynx. Its purpose is to equalize pressure on either side of the ear drum.

Rhinovirus— A virus that infects the upper respiratory system and causes the common cold.

Common cold

Definition

The common cold is a viral infection of the upper respiratory system , including the nose, throat, sinuses, eustachian tubes, trachea, larynx, and bronchial tubes. Although over 200 different viruses can cause a cold, 30–50% are caused by a group of viruses known as rhinoviruses. Almost all colds clear up in less than two weeks without complications.

Description

Colds, sometimes called rhinovirus or coronavirus infections, are common, frequently occurring illnesses. It is estimated that the average person has more than 50 colds during a lifetime. Anyone can get a cold, although preschool and grade school children catch them more frequently than adolescents and adults because they have not been exposed to the cold viruses and developed immunity. Repeated exposure to the viruses that cause colds creates partial immunity.

Although most colds resolve on their own without complications, they are a leading cause of visits to the doctor and of time lost from work and school. Treating symptoms of the common cold has given rise to a multi- million dollar industry in over-the-counter medications.

Cold season in the United States begins in early autumn and extends through early spring. Colds occur more frequently during this period because people tend to spend more time indoors where it is easier for viruses to spread from one person to another. Although it is not true that getting wet or being in a draft causes a cold (a person has to come in contact with the virus to catch a cold), certain conditions may lead to increased susceptibility. These include:

• fatigue and overwork
• emotional stress
• poor nutrition
• smoking
• living or working in crowded conditions

Colds make the upper respiratory system less resistant to bacterial infection. Secondary bacterial infection may lead to otitis media (middle ear infection), bronchitis, pneumonia , sinus infection, or strep throat . Patients with chronic lung disease, asthma , diabetes, or a weakened immune system are more likely to develop these complications.

Causes and symptoms

Colds are caused by more than 200 different viruses. The most common groups are rhinoviruses and coronaviruses. Different viruses are more infectious at different seasons of the year, but determining the exact virus causing the cold is not important for purposes of treatment.

People with colds are contagious during the first two to four days of the infection. Colds pass from person to person in several ways. When an infected person coughs, sneezes, or speaks, tiny fluid droplets containing the virus are expelled. If these are inhaled by others, the virus may establish itself in their noses and airways.

Colds can also be passed through direct contact. If a person with a cold touches his runny nose or watery eyes, then shakes hands with another person, the virus is transferred to the uninfected person. When the uninfected person touches his mouth, nose, or eyes, the virus is transported to an environment where it can reproduce and produce symptoms of illness.

Finally, cold viruses can be spread through inanimate objects such as doorknobs, telephones, or toys that become contaminated with the virus. This is a common method of viral transmission in childcare centers. When a child with a cold touches his runny nose, then plays with a toy, the virus may be transferred to the toy. When another child plays with the toy a short time later, he may pick up the virus on his hands. When the second child touches his contaminated hands to his eyes, nose, or mouth the virus is once again in an environment conducive to replication.

Once acquired, the cold virus attaches itself to the mucosal lining of the nasal passages and sinuses. This causes the infected cells to release a chemical called histamine. Histamine increases blood flow to the infected cells, causing swelling, congestion, and increased mucus production. One to three days following infection, the affected individual begins to experience cold symptoms.

The first cold symptoms are sore throat , runny nose, and sneezing. The initial discharge from the nose is clear and thin. Later it changes to a thick yellow or greenish discharge. Most adults do not develop a fever when they contract a cold. Young children may develop fevers to 102°F (38.9°C).

Along with a runny nose and fever, symptoms of a cold include coughing, sneezing, nasal congestion, headache, myalgias (muscle aches), chills, sore throat, hoarseness, watery eyes, fatigue, and loss of appetite. The cough that accompanies a cold is usually intermittent and nonproductive (dry).

Most people begin to feel better four to five days after cold symptoms become noticeable. All symptoms are generally gone within ten days, except for a dry cough that may linger for up to three weeks.

Colds increase susceptibility to bacterial infections such as strep throat, middle ear infections, and sinus infections. Individuals with symptoms that do not begin to improve within a week; or those with chest pain , persistent fever (fever for longer than a few days), difficulty breathing, productive cough, skin rash, swollen glands, or whitish spots on the tonsils or throat should consult a health care practitioner. The health care practitioner will determine if these patients have acquired secondary bacterial infections that require treatment with antibiotics .

People who have emphysema , chronic pulmonary disease, diabetes, or a weakened immune system—either from diseases such as AIDS or leukemia, or as the result of immunosuppressive medications (corticosteroids , chemotherapy drugs)—should consult a health care practitioner when they experience cold symptoms. Patients with these chronic health problems are at greater risk for secondary infections.

Diagnosis

Colds are readily diagnosed using a focused history and physical examination . There are no laboratory tests readily available to detect or isolate the causative virus. When patients seek medical care, the health care practitioner (physician or mid-level practitioner) may perform a throat culture or blood test to rule out a secondary bacterial infection.

Though viruses cause both colds and influenza (flu), influenza is usually a more serious viral illness. A cold develops gradually over the course of a day or two. Patients may have a runny nose, sneezing, mild sore throat, headache and body aches, but usually they do not have fever or feel completely exhausted. Influenza symptoms develop suddenly. They are similar to cold symptoms, but usually more severe. Patients with influenza generally feel sicker than those with colds because the influenza virus produces symptoms throughout the body—muscle aches, weakness, fever, and chills.

Allergies also produce rhinitis (runny nose). Symptoms of allergic rhinitis—sneezing, nasal congestion, and itchy, runny nose—are commonly caused by dust mites, animal dander, or indoor molds. Other environmental irritants such as smoke, pollen, pollutants, pesticides, and perfumes may also trigger allergic rhinitis. Allergies are usually more persistent than the common cold. An allergist can perform tests to determine if the persistent cold-like symptoms are attributable to an allergic reaction. Also, some people get a runny nose when they go outside in winter and breathe cold air. This type of runny nose, called vasomotor rhinitis, is not a symptom of a cold.

Treatment

There are no medicines that will cure the common cold. Given time, the body's immune system will make antibodies to fight the infection, and the cold will resolve without any intervention. Antibiotics are useless against a cold. There are, however, medications to provide symptom relief. Pharmaceutical companies in the United States promote an array of products designed to relieve cold symptoms. Most products contain antihistamines , decongestants, and/or pain relievers.

Antihistamines block the action of the chemical histamine that is produced when the cold virus invades the cells lining the nasal passages. Histamine increases blood flow and causes the cells to swell. Antihistamines relieve the symptoms of sneezing, runny nose, itchy eyes, and congestion. Side effects are dry mouth and drowsiness, especially with the first few doses. Patients should be advised against taking antihistamines if they intend to drive or operate dangerous equipment. The brand names of common over-the-counter antihistamines are Chlor- Trimeton, Dimetapp, Tavist, and Actifed. The generic names of two common antihistamines are chlorpheniramine and diphenhydramine.

Decongestants work to constrict the blood flow to the vessels in the nose. This can shrink the tissue, reduce congestion, and open inflamed nasal passages, making breathing easier. Decongestants can cause patients to feel jittery or prevent them from sleeping. They should not be prescribed for or used by patients with heart disease, high blood pressure , or glaucoma . The brand names of some common decongestants are Neo-Synepherine, Novafed, and Sudafed. The generic names of common decongestants are phenylephrine, phenylpropanolamine, pseudoephedrine, and in nasal sprays naphazoline, oxymetazoline, and xylometazoline.

Many over-the-counter medications are combinations of antihistamines and decongestants. They also may include an ache and pain reliever, such as acetaminophen (Datril, Tylenol, Panadol) or ibuprofen (Advil, Nuprin, Motrin, Medipren), and a cough suppressant (dextromethorphan). Common combination medications include Tylenol Cold and Flu, Triaminic, Sudafed Plus, and Tavist D. Aspirin should not be given to children with colds because of its association with a risk of Reye's syndrome.

Nasal sprays and nose drops also are promoted to relieve nasal congestion. These usually contain a decongestant, but the decongestant can act more quickly and strongly than ones found in pills or liquids because it is applied locally, directly in the nose. Congestion usually returns after a few hours.

Patients may become dependent on nasal sprays and nose drops. If used for a long time, users may suffer withdrawal symptoms when the products are discontinued. This withdrawal condition is called rhinitis medicamentosa. Nasal sprays and nose drops should not be used for more than a few days. Patients should be instructed to adhere to product-specific recommendations about duration and frequency of use.

Individuals have varied reactions to different cold medications and may find some more helpful than others. A medication may be effective initially, then lose some of its effectiveness. Children sometimes react differently from adults. Patients should be cautioned against giving over-the-counter cold remedies to infants without first consulting a health care professional.

Care should be taken not to exceed the recommended dosages, especially when combination medications or nasal sprays are used. Individuals should determine whether they wish to use any of these medications based on their need for symptom relief, since none of them shorten the duration of a cold. Patients confused about the use of over-the-counter cold remedies should be encouraged to seek counsel from a health care practitioner, such as a physician, mid-level practitioner, nurse, or pharmacist.

Along with the optional use of over-the-counter cold remedies, there are some self-care steps that patients can take to ease their discomfort. These include:

• Drinking plenty of fluids, but avoiding acidic juices, which may irritate the throat.
• Gargling with warm salt water (made by adding one teaspoon of salt to 8 oz of water) for a sore throat.
• Not smoking.
• Getting plenty of rest.
• Using a cool-mist room humidifier to ease congestion and sore throat.
• Rubbing Vaseline or other lubricant under the nose to prevent irritation from frequent nose blowing.
• For babies too young to blow their noses, the mucus should be suctioned gently with an infant nasal aspirator. It may be necessary to soften the mucus first with a few drops of salt water.

Many alternative health care practitioners believe that people contract colds because their immune systems are weak. They observe that everyone is exposed to cold viruses, but not everyone becomes ill. The difference seems to be in the ability of the immune system to fight infection. Prevention focuses on strengthening the immune system by eating a healthy diet low in sugars and high in fresh fruits and vegetables, practicing meditation to reduce stress, and getting regular moderate exercise .

There is some scientific evidence that phytochemicals, nutrients found in fruits and vegetables, may act to prevent viral infections such as colds. An herb, Echinacea purpurea, is widely used to prevent and treat colds. It is believed to act as a transient (brief) immunostimulant, however, patients with autoimmune diseases should not use it since continuous use had been linked to immunosuppression.

The use of zinc lozenges every two hours along with high doses of vitamin C is another an alternative therapy. Some alternative practitioners also suggest eliminating dairy products for the duration of the cold because they contend that dairy products encourage production of mucus.

The use of zinc lozenges to treat cold symptoms remains controversial. Some studies evaluating the effectiveness of zinc gluconate lozenges found that using zinc in the first 24 hours after cold symptoms occurred shortened the duration of symptoms. Other studies refuted these findings.

Prognosis

Given time, the body will generate antibodies to the cold. Most colds last a week to ten days, and patients start feeling better within four or five days. Occasionally, a cold will lead to a secondary bacterial infection that causes strep throat, bronchitis, pneumonia, sinus infection, or a middle ear infection. These conditions usually resolve rapidly when treated with the appropriate antibiotic.

Health care team roles

Nearly all health care professionals encounter patients seeking advice about, or treatment for, cold symptoms. Physicians, mid-level practitioners, nurses, pharmacists, and health educators are often called upon to evaluate symptoms, instruct patients in self-care techniques, and reassure them that colds are self-limiting disorders that generally resolve without treatment.

Patient education

Along with strategies to prevent the spread of cold viruses, it is vitally important for health care professionals to teach patients that antibiotics have no role in the treatment of the common cold. Antibiotics should not be prescribed for colds because, as of 2001, there are no antibiotics effective against the viruses that cause colds. Further, antibiotics should not be prescribed unnecessarily because they can produce side effects such as rash and diarrhea . Another dangerous public health consequence of overuse of antibiotics is the emergence of strains of bacteria that are resistant to these medications.

Prevention

It is not possible to prevent colds because the viruses that cause colds are common and highly infectious. There are, however, steps individuals can take to reduce their spread. These include:

• Washing hands well and frequently, especially after touching the nose and before handling food.
• Covering the mouth and nose when sneezing.
• Disposing of used tissues properly.
• Avoiding close contact with an infected individual during the first two to four days of their infection.
• Not sharing food, eating utensils, or cups with others.
• Avoiding crowded places where cold germs can spread.
• Eating a healthy diet and getting adequate sleep.

KEY TERMS

Bronchial tubes —The major airways to the lungs and their main branches.

Coronavirus —A type of virus that causes respiratory disease and gastroenteritis.

Corticosteroids —A group of hormones produced naturally by the adrenal gland or manufactured synthetically. They are often used to treat inflammation. Examples include cortisone and prednisone.

Eustachian tube —A thin tube between the middle ear and the pharnyx. Its purpose is to equalize pressure on either side of the ear drum.

Rhinovirus —A virus that infects the upper respiratory system and causes the common cold.

Resources

BOOKS

Castleman, Michael. "Cold and Flu Therapy." In Nature's Cures. Emmaus, PA: Rodale Press, 1996.

"Colds and Flu." In Alternative Medicine: The Definitive Guide, compiled by the Burton Goldeberg Group. Puyallup, WA: Future Medicine Publishing, 1994.

Pelletier, Kenneth R. The Best Alternative Medicine What Works? What Does Not? New York: Simon & Schuster, 2000.

Silverstein Alvin, et al. Common Cold and Flu (Diseases and People). Springfield, MA: Enslow Publishers, 1996.

OTHER

"Zinc: A Weapon Against the Commmon Cold?" Mayo Health Oasis. <http://www.mayohealth.org/mayo/9709/htm/zinc.htm>. (9 September 1997).

Barbara Wexler

Common Cold

Definition

The common cold is a viral infection of the upper respiratory system, including the nose, throat, sinuses, eustachian tubes, trachea, larynx, and bronchial tubes. Although over 200 different viruses can cause a cold, 30-50% are caused by a group of viruses known as rhinoviruses. Almost all colds clear up in less than two weeks without complications.

Description

Colds, sometimes called rhinovirus or coronavirus infections, are common, frequently occurring illnesses. It is estimated that the average person has more than 50 colds during a lifetime. Anyone can get a cold, although preschool and grade school children catch them more frequently than adolescents and adults because they have not been exposed to the cold viruses and developed immunity. Repeated exposure to the viruses that cause colds creates partial immunity.

Although most colds resolve on their own without complications, they are a leading cause of visits to the doctor and of time lost from work and school. Treating symptoms of the common cold has given rise to a multimillion dollar industry in over-the-counter medications.

Cold season in the United States begins in early autumn and extends through early spring. Colds occur more frequently during this period because people tend to spend more time indoors where it is easier for viruses to spread from one person to another. Although it is not true that getting wet or being in a draft causes a cold (a person has to come in contact with the virus to catch a cold), certain conditions may lead to increased susceptibility. These include:

• fatigue and overwork
• emotional stress

• poor nutrition
• smoking
• living or working in crowded conditions

Colds make the upper respiratory system less resistant to bacterial infection. Secondary bacterial infection may lead to otitis media (middle ear infection), bronchitis, pneumonia, sinus infection, or strep throat. Patients with chronic lung disease, asthma, diabetes, or a weakened immune system are more likely to develop these complications.

Causes and symptoms

Colds are caused by more than 200 different viruses. The most common groups are rhinoviruses and coronaviruses. Different viruses are more infectious at different seasons of the year, but determining the exact virus causing the cold is not important for purposes of treatment.

People with colds are contagious during the first two to four days of the infection. Colds pass from person to person in several ways. When an infected person coughs, sneezes, or speaks, tiny fluid droplets containing the virus are expelled. If these are inhaled by others, the virus may establish itself in their noses and airways.

Colds can also be passed through direct contact. If a person with a cold touches his runny nose or watery eyes, then shakes hands with another person, the virus is transferred to the uninfected person. When the uninfected person touches his mouth, nose, or eyes, the virus is transported to an environment where it can reproduce and produce symptoms of illness.

Finally, cold viruses can be spread through inanimate objects such as doorknobs, telephones, or toys that become contaminated with the virus. This is a common method of viral transmission in childcare centers. When a child with a cold touches his runny nose, then plays with a toy, the virus may be transferred to the toy. When another child plays with the toy a short time later, he may pick up the virus on his hands. When the second child touches his contaminated hands to his eyes, nose, or mouth the virus is once again in an environment conducive to replication.

Once acquired, the cold virus attaches itself to the mucosal lining of the nasal passages and sinuses. This causes the infected cells to release a chemical called histamine. Histamine increases blood flow to the infected cells, causing swelling, congestion, and increased mucus production. One to three days following infection, the affected individual begins to experience cold symptoms.

The first cold symptoms are sore throat, runny nose, and sneezing. The initial discharge from the nose is clear and thin. Later it changes to a thick yellow or greenish discharge. Most adults do not develop a fever when they contract a cold. Young children may develop fevers to 102 °F (38.9 °C).

Along with a runny nose and fever, symptoms of a cold include coughing, sneezing, nasal congestion, headache, myalgias (muscle aches), chills, sore throat, hoarseness, watery eyes, fatigue, and loss of appetite. The cough that accompanies a cold is usually intermittent and nonproductive (dry).

Most people begin to feel better four to five days after cold symptoms become noticeable. All symptoms are generally gone within ten days, except for a dry cough that may linger for up to three weeks.

Colds increase susceptibility to bacterial infections such as strep throat, middle ear infections, and sinus infections. Individuals with symptoms that do not begin to improve within a week or those with chest pain, persistent fever (fever for longer than a few days), difficulty breathing, productive cough, skin rash, swollen glands, or whitish spots on the tonsils or throat should consult a health care practitioner. The health care practitioner will determine if these patients have acquired secondary bacterial infections that require treatment with antibiotics.

People who have emphysema, chronic pulmonary disease, diabetes, or a weakened immune system—either from diseases such as AIDS or leukemia, or as the result of immunosuppressive medications (corticosteroids, chemotherapy drugs)—should consult a health care practitioner when they experience cold symptoms. Patients with these chronic health problems are at greater risk for secondary infections.

Diagnosis

Colds are readily diagnosed using a focused history and physical examination. There are no laboratory tests readily available to detect or isolate the causative virus. When patients seek medical care, the health care practitioner (physician or mid-level practitioner) may perform a throat culture or blood test to rule out a secondary bacterial infection.

Though viruses cause both colds and influenza (flu), influenza is usually a more serious viral illness. A cold develops gradually over the course of a day or two. Patients may have a runny nose, sneezing, mild sore throat, headache and body aches, but usually they do not have fever or feel completely exhausted. Influenza symptoms develop suddenly. They are similar to cold symptoms, but usually more severe. Patients with influenza generally feel sicker than those with colds because the influenza virus produces symptoms throughout the body—muscle aches, weakness, fever, and chills.

Allergies also produce rhinitis (runny nose). Symptoms of allergic rhinitis—sneezing, nasal congestion, and itchy, runny nose—are commonly caused by dust mites, animal dander, or indoor molds. Other environmental irritants such as smoke, pollen, pollutants, pesticides, and perfumes may also trigger allergic rhinitis. Allergies are usually more persistent than the common cold. An allergist can perform tests to determine if the persistent cold-like symptoms are attributable to an allergic reaction. Also, some people get a runny nose when they go outside in winter and breathe cold air. This type of runny nose, called vasomotor rhinitis, is not a symptom of a cold.

Treatment

There are no medicines that will cure the common cold. Given time, the body's immune system will make antibodies to fight the infection, and the cold will resolve without any intervention. Antibiotics are useless against a cold. There are, however, medications to provide symptom relief. Pharmaceutical companies in the United States promote an array of products designed to relieve cold symptoms. Most products contain antihistamines, decongestants, and/or pain relievers.

Antihistamines block the action of the chemical histamine that is produced when the cold virus invades the cells lining the nasal passages. Histamine increases blood flow and causes the cells to swell. Antihistamines relieve the symptoms of sneezing, runny nose, itchy eyes, and congestion. Side effects are dry mouth and drowsiness, especially with the first few doses. Patients should be advised against taking antihistamines if they intend to drive or operate dangerous equipment. The brand names of common over-the-counter antihistamines are Chlor-Trimeton, Dimetapp, Tavist, and Actifed. The generic names of two common antihistamines are chlorpheniramine and diphenhydramine.

Decongestants work to constrict the blood flow to the vessels in the nose. This can shrink the tissue, reduce congestion, and open inflamed nasal passages, making breathing easier. Decongestants can cause patients to feel jittery or prevent them from sleeping. They should not be prescribed for or used by patients with heart disease, high blood pressure, or glaucoma. The brand names of some common decongestants are Neo-Synepherine, Novafed, and Sudafed. The generic names of common decongestants are phenylephrine, phenylpropanolamine, pseudoephedrine, and in nasal sprays naphazoline, oxymetazoline, and xylometazoline.

Many over-the-counter medications are combinations of antihistamines and decongestants. They also may include an ache and pain reliever, such as acetaminophen (Datril, Tylenol, Panadol) or ibuprofen (Advil, Nuprin, Motrin, Medipren), and a cough suppressant (dextromethorphan). Common combination medications include Tylenol Cold and Flu, Triaminic, Sudafed Plus, and Tavist D. Aspirin should not be given to children with colds because of its association with a risk of Reye's syndrome.

Nasal sprays and nose drops also are promoted to relieve nasal congestion. These usually contain a decongestant, but the decongestant can act more quickly and strongly than ones found in pills or liquids because it is applied locally, directly in the nose. Congestion usually returns after a few hours.

Patients may become dependent on nasal sprays and nose drops. If used for a long time, users may suffer withdrawal symptoms when the products are discontinued. This withdrawal condition is called rhinitis medicamentosa. Nasal sprays and nose drops should not be used for more than a few days. Patients should be instructed to adhere to product-specific recommendations about duration and frequency of use.

Individuals have varied reactions to different cold medications and may find some more helpful than others. A medication may be effective initially, then lose some of its effectiveness. Children sometimes react differently from adults. Patients should be cautioned against giving over-the-counter cold remedies to infants without first consulting a health care professional.

Care should be taken not to exceed the recommended dosages, especially when combination medications or nasal sprays are used. Individuals should determine whether they wish to use any of these medications based on their need for symptom relief, since none of them shorten the duration of a cold. Patients confused about the use of over-the-counter cold remedies should be encouraged to seek counsel from a health care practitioner, such as a physician, midlevel practitioner, nurse, or pharmacist.

Along with the optional use of over-the-counter cold remedies, there are some self-care steps that patients can take to ease their discomfort. These include:

• Drinking plenty of fluids, but avoiding acidic juices, which may irritate the throat.
• Gargling with warm salt water (made by adding one teaspoon of salt to 8 oz of water) for a sore throat.
• Not smoking.
• Getting plenty of rest.
• Using a cool-mist room humidifier to ease congestion and sore throat.
• Rubbing Vaseline or other lubricant under the nose to prevent irritation from frequent nose blowing.
• For babies too young to blow their noses, the mucus should be suctioned gently with an infant nasal aspirator. It may be necessary to soften the mucus first with a few drops of salt water.

Many alternative health care practitioners believe that people contract colds because their immune systems are weak. They observe that everyone is exposed to cold viruses, but not everyone becomes ill. The difference seems to be in the ability of the immune system to fight infection. Prevention focuses on strengthening the immune system by eating a healthy diet low in sugars and high in fresh fruits and vegetables, practicing meditation to reduce stress, and getting regular moderate exercise.

There is some scientific evidence that phytochemicals, nutrients found in fruits and vegetables, may act to prevent viral infections such as colds. An herb, Echinacea purpurea, is widely used to prevent and treat colds. It is believed to act as a transient (brief) immunostimulant, however, patients with autoimmune diseases should not use it since continuous use has been linked to immunosuppression.

The use of zinc lozenges every two hours along with high doses of vitamin C is another an alternative therapy. Some alternative practitioners also suggest eliminating dairy products for the duration of the cold because they contend that dairy products encourage production of mucus.

The use of zinc lozenges to treat cold symptoms remains controversial. Some studies evaluating the effectiveness of zinc gluconate lozenges found that using zinc in the first 24 hours after cold symptoms occurred shortened the duration of symptoms. Other studies refuted these findings.

Prognosis

Given time, the body will generate antibodies to the cold. Most colds last a week to ten days, and patients start feeling better within four or five days. Occasionally, a cold will lead to a secondary bacterial infection that causes strep throat, bronchitis, pneumonia, sinus infection, or a middle ear infection. These conditions usually resolve rapidly when treated with the appropriate antibiotic.

KEY TERMS

Bronchial tubes— The major airways to the lungs and their main branches.

Coronavirus— A type of virus that causes respiratory disease and gastroenteritis.

Corticosteroids— A group of hormones produced naturally by the adrenal gland or manufactured synthetically. They are often used to treat inflammation. Examples include cortisone and prednisone.

Eustachian tube— A thin tube between the middle ear and the pharnyx. Its purpose is to equalize pressure on either side of the ear drum.

Rhinovirus— A virus that infects the upper respiratory system and causes the common cold.

Health care team roles

Nearly all health care professionals encounter patients seeking advice about, or treatment for, cold symptoms. Physicians, mid-level practitioners, nurses, pharmacists, and health educators are often called upon to evaluate symptoms, instruct patients in self-care techniques, and reassure them that colds are self-limiting disorders that generally resolve without treatment.

Patient education

Along with strategies to prevent the spread of cold viruses, it is vitally important for health care professionals to teach patients that antibiotics have no role in the treatment of the common cold. Antibiotics should not be prescribed for colds because, as of 2001, there are no antibiotics effective against the viruses that cause colds. Further, antibiotics should not be prescribed unnecessarily because they can produce side effects such as rash and diarrhea. Another dangerous public health consequence of overuse of antibiotics is the emergence of strains of bacteria that are resistant to these medications.

Prevention

It is not possible to prevent colds because the viruses that cause colds are common and highly infectious. There are, however, steps individuals can take to reduce their spread. These include:

• Washing hands well and frequently, especially after touching the nose and before handling food.
• Covering the mouth and nose when sneezing.
• Disposing of used tissues properly.
• Avoiding close contact with an infected individual during the first two to four days of their infection.
• Not sharing food, eating utensils, or cups with others.
• Avoiding crowded places where cold germs can spread.
• Eating a healthy diet and getting adequate sleep.

Resources

BOOKS

Castleman, Michael. "Cold and Flu Therapy." In Nature's Cures. Emmaus, PA: Rodale Press, 1996.

"Colds and Flu." In Alternative Medicine: The Definitive Guide, compiled by the Burton Goldeberg Group. Puyallup, WA: Future Medicine Publishing, 1994.

Pelletier, Kenneth R. The Best Alternative Medicine What Works? What Does Not? New York: Simon & Schuster, 2000.

Silverstein Alvin, et al. Common Cold and Flu (Diseases and People). Springfield, MA: Enslow Publishers, 1996.

OTHER

"Zinc: A Weapon Against the Commmon Cold?" Mayo Health Oasis. 〈http://www.mayohealth.org/mayo/9709/htm/zinc.htm〉. (9 September 1997).

Common cold

Definition

The common cold, also called a rhinovirus or coronavirus infection, is a viral infection of the upper respiratory system, including the nose, throat, sinuses, eustachian tubes, trachea, larynx, and bronchial tubes. Over 200 different viruses can cause a cold. Almost all colds clear up in less than two weeks without complications.

Description

Cold season in the United States begins in early autumn and extends through early spring. Although it is not true that getting wet or being in a draft causes a cold (a person has to come in contact with the virus to catch a cold), certain conditions may lead to increased susceptibility. These include:

• fatigue and overwork
• emotional stress
• poor nutrition
• smoking
• living or working in crowded conditions

Although most colds resolve on their own without complications, they are a leading cause of visits to the doctor and of time lost from work and school. Treating symptoms of the common cold has given rise in the United States to a multi-million dollar industry in over-the-counter medications.

Colds make the upper respiratory system less resistant to bacterial infection. Secondary bacterial infection may lead to middle ear infection (otitis media), bronchitis, pneumonia , sinus infection, or strep throat . People with chronic lung disease, asthma , diabetes, or a weakened immune system are more likely to develop these complications.

Transmission

People with colds are contagious during the first two to four days of the infection. Colds pass from person to person in several ways. When an infected person coughs, sneezes, or speaks, tiny fluid droplets containing the virus are expelled. If these are breathed in by other people, the virus may establish itself in their noses and airways.

Colds may also be passed through direct contact. If a person with a cold touches his runny nose or watery eyes, then shakes hands with another person, some of the virus is transferred to the uninfected person. If that person then touches his mouth, nose, or eyes, the virus is transferred to an environment where it can reproduce and cause a cold.

In addition, cold viruses can be spread through inanimate objects (door knobs, telephones, toys ) that become contaminated with the virus. This is a common method of transmission in childcare centers. If a child with a cold touches his runny nose, then plays with a toy, some of the virus may be transferred to the toy. When another child plays with the toy a short time later, he may pick up some of the virus on his hands. The second child then touches his contaminated hands to his eyes, nose, or mouth and transfers some of the cold virus to himself.

Demographics

Colds are the most common illness to strike any part of the body, with over one billion colds in the United States each year. Anyone can get a cold, although pre-school and grade school children catch them more frequently than adolescents and adults. Children average six to ten colds a year. In families with children in school, the number can be as high as 12 per year. Women, especially those aged 20 to 30 years old, have more colds than men, possibly because of their closer contact with children. Individuals older than 60 usually have fewer than one cold per year. Repeated exposure to viruses causing colds creates partial immunity.

Causes and symptoms

Colds are caused by more than 200 different viruses. The most common groups are rhinoviruses and coronaviruses. Different groups of viruses are more infectious at different seasons of the year, but knowing the exact virus causing the cold is not important in treatment.

Once acquired, the cold virus attaches itself to the lining of the nasal passages and sinuses. This condition causes the infected cells to release a chemical called histamine. Histamine increases the blood flow to the infected cells, causing swelling, congestion, and increased mucus production. Within one to three days the infected person begins to show cold symptoms.

The first cold symptoms are a tickle in the throat, runny nose, and sneezing. The initial discharge from the nose is clear and thin. Later it changes to a thick yellow or greenish discharge. Most adults do not develop a fever when they catch a cold. Young children may develop a low fever of up to 102°F (38.9°C).

In addition to a runny nose and fever, signs of a cold include coughing, sneezing, nasal congestion, headache , muscle ache, chills, sore throat , hoarseness, watery eyes, tiredness, and lack of appetite. The cough that accompanies a cold is usually intermittent and dry.

Most people begin to feel better four to five days after their cold symptoms become noticeable. All symptoms are generally gone within ten days, except for a dry cough that may linger for up to three weeks.

When to call the doctor

Colds make people more susceptible to bacterial infections such as strep throat, middle ear infections, and sinus infections. People who have colds that do not begin to improve within a week or who experience chest pain , fever for more than a few days, difficulty breathing, bluish lips or fingernails, a cough that brings up greenish-yellow or grayish sputum, skin rash, swollen glands, or whitish spots on the tonsils or throat should consult a doctor to see to determine if they have acquired a secondary bacterial infection that needs to be treated with an antibiotic.

Children who have chronic lung disease, diabetes, or a weakened immune system—either from diseases such as AIDS or leukemia or as the result of medications, (corticosteroids, chemotherapy drugs)—should consult their doctor if they get a cold. Children with these health problems are more likely to get a secondary infection. For children with asthma, colds are a common trigger of asthma symptoms.

Diagnosis

Colds are diagnosed by observing a child's symptoms. There are no laboratory tests as of 2004 for detecting the cold virus. However, a doctor may do a throat culture or blood test to rule out a secondary infection.

Influenza is sometimes confused with a cold, but flu causes much more severe symptoms, as well as a fever. Allergies to molds or pollens also can make the nose run. Allergies are usually more persistent than the common cold. An allergist can do tests to determine if the cold-like symptoms are being caused by an allergic reaction. Also, some people get a runny nose when they go outside in winter and breathe cold air. This type of runny nose is not a symptom of a cold.

Treatment

There are no medicines that will cure the common cold. Given time, the body's immune system makes antibodies to fight the infection, and the cold is resolved without any intervention. Antibiotics are useless against a cold. However, there are many products that have been developed by pharmaceutical companies in the United States designed to relieve cold symptoms. These products usually contain antihistamines, decongestants , and/or pain relievers.

Antihistamines block the action of the chemical histamine that is produced when the cold virus invades the cells lining the nasal passages. Histamine increases blood flow and causes the cells to swell. Antihistamines are taken to relieve the symptoms of sneezing, runny nose, itchy eyes, and congestion. Side effects are dry mouth and drowsiness, especially with the first few doses. Antihistamines should not be taken by people who are driving or operating dangerous equipment. Some people have allergic reactions to antihistamines. Common over-the-counter antihistamines are Chlor-Trimeton, Dimetapp, Tavist, and Actifed. The generic name for two common antihistamines are chlorpheniramine and diphenhydramine.

Decongestants work to constrict the blood flow to the vessels in the nose. They can shrink the tissue, reduce congestion, and open inflamed nasal passages, making breathing easier. Decongestants can make people feel jittery or keep them from sleeping. They should not be used by people with heart disease, high blood pressure, or glaucoma. Some common decongestants are Neo-Synepherine, Novafed, and Sudafed. The generic names of common decongestants include phenylephrine, phenylpropanolamine, pseudoephedrine, and in nasal sprays naphazoline, oxymetazoline, and xylometazoline.

Many over-the-counter medications are combinations of both antihistamines and decongestants; an ache and pain reliever, such as acetaminophen (Datril, Tylenol, Panadol) or ibuprofen (Advil, Nuprin, Motrin, Medipren); and a cough suppressant (dextromethorphan). Common combination medications include Tylenol Cold and Flu, Triaminic, Sudafed Plus, and Tavist D. Aspirin should not be given to children with a cold because of its association with a risk of Reye's syndrome .

Nasal sprays and nose drops are other products promoted for reducing nasal congestion. These usually contain a decongestant, but the decongestant in the nasal preparations can act more quickly and strongly than ones found in pills or liquids because it is applied directly in the nose. Congestion returns after a few hours. People can become dependent on nasal sprays and nose drops. If used for a long time, users may suffer withdrawal symptoms when these products are discontinued. The label on the preparation should be checked for recommendations on length and frequency of use, since nasal sprays and nose drops should not be used for more than a few days.

People react differently to different cold medications and may find some more helpful than others. A medication may be effective initially then lose some of its effectiveness. Children sometimes react differently than adults. Over-the-counter cold remedies should not be given to infants without consulting a doctor first.

Care should be taken not to exceed the recommended dosages, especially when combination medications or nasal sprays are taken. These medicines do not shorten or cure a cold; at best they can only help a person feel more comfortable.

In addition to the optional use of over-the-counter cold remedies, there are some self-care steps that can be taken to ease discomfort. These include:

• drinking plenty of fluids, but avoiding acidic juices, which may irritate the throat
• gargling with warm salt water—made by adding one teaspoon of salt to 8 oz of water—for a sore throat
• avoiding second-hand smoke
• getting plenty of rest
• using a cool-mist room humidifier to ease congestion and sore throat
• rubbing Vaseline or other lubricant under the nose to prevent irritation from frequent nose blowing
• for babies too young to blow their noses, the mucus should be suctioned gently with an infant nasal aspirator (It may be necessary to soften the mucus first with a few drops of salt water.)

Alternative treatment

Alternative practitioners emphasize that people get colds because their immune systems are weak. They point out that everyone is exposed to cold viruses, but not everyone gets every cold. The difference seems to be in the ability of the immune system to fight infection. Prevention focuses on strengthening the immune system by eating a healthy diet low in sugars and high in fresh fruits and vegetables, practicing meditation or using other means to reduce stress, and getting regular moderate exercise .

Once cold symptoms appear, some naturopathic practitioners believe the symptoms should be allowed to run their course without interference. Others suggest the following:

• Aromatherapy remedy: Inhaling a steaming mixture of lemon oil, thyme oil, eucalyptus, and tea tree oil (Melaleuca spp.).
• Ayurvedic medicinal remedy: Gargling with a mixture of water, salt, and turmeric powder or astringents, such as alum, sumac, sage, and bayberry to ease a sore throat.
• Herbal remedies: Taking coneflower (Echinacea spp.) or goldenseal (Hydrastis canadensis ). Other useful herbs to reduce symptoms are yarrow (Achillea millefolium ), eyebright (Euphrasia officinalis ), garlic (Allium sativum ), and onions (Allium cepa ).
• Homeopathic remedies: Microdoses of Viscue album, Natrum muriaticum, Allium cepa, or Nux vomica.
• Chinese traditional medicinal remedies: Taking yin chiao (sometimes transliterated as yinquiao) tablets that contain honeysuckle and forsythia when symptoms appear as well as using natural herb loquat syrup for cough and sinus congestion.
• Nutritional therapy: The use of zinc lozenges every two hours along with high doses of vitamin C as well as eliminating dairy products for the duration of the cold.

Prognosis

Given time, the body produces antibodies to cure itself of a cold. Most colds last a week to ten days. Most people start feeling better within four or five days. Occasionally a cold will lead to a secondary bacterial infection that causes strep throat, bronchitis, pneumonia, sinus infection, or a middle ear infection. These conditions usually clear up rapidly when treated with an antibiotic.

Prevention

It is not possible to prevent colds because the viruses that cause colds are common and highly infectious. However, there are some steps individuals can take to reduce their spread. These include:

• washing hands well and frequently, especially after touching the nose or before handling food
• using instant hand sanitizers, which are antiseptics and not antibiotics
• covering the mouth and nose when sneezing
• disposing of used tissues properly
• avoiding close contact with someone who has a cold during the first two to four days of their infection
• not sharing food, eating utensils, or cups
• using paper towels rather than shared cloth towels
• avoiding crowded places where cold germs can spread
• eating a healthy diet and getting adequate sleep
• using a daycare facility with six or fewer children, to dramatically reduce germ contact

Parental concerns

The over-use of antibiotics has led to the development of antibiotic-resistant stains of bacteria. For these bacteria, antibiotics may be ineffective. Therefore, parents should not press the doctor to prescribe antibiotics when their children only have a cold.

Also, a parent should not give a child aspirin during a cold, because aspirin has been linked to the development of Reye's syndrome in children recovering from viral illnesses, especially influenza (flu) or chickenpox . Reye's syndrome can lead to permanent brain damage or death.

KEY TERMS

Bronchial tubes —The major airways to the lungs and their main branches.

Coronavirus —A genus of viruses that cause respiratory diseases and gastroenteritis.

Corticosteroids —A group of hormones produced naturally by the adrenal gland or manufactured synthetically. They are often used to treat inflammation. Examples include cortisone and prednisone.

Eustachian tube —A thin tube between the middle ear and the pharnyx. Its purpose is to equalize pressure on either side of the ear drum.

Reye's syndrome —A serious, life-threatening illness in children, usually developing after a bout of flu or chickenpox, and often associated with the use of aspirin. Symptoms include uncontrollable vomiting, often with lethargy, memory loss, disorientation, or delirium. Swelling of the brain may cause seizures, coma, and in severe cases, death.

Rhinovirus —A group of small RNA viruses that infects the upper respiratory system and causes the common cold.

Resources

BOOKS

Royston, Angela. Colds (It's Catching) Oxford, UK: Heinemann Library, 2001.

Silverstein, Alvin. Common Colds. Minneapolis, MN: Sagebrush Corp., 2001.

Judith Sims Tish Davidson, A.M.