Fungal infections

Definition

Fungal infections are infections caused by fungi, organisms of the kingdom Fungi, that includes yeasts, molds, and mushrooms.

Description

In nature, there are hundreds of thousands of different families and species of fungi. Yeasts consist of round or oval single cells. Other fungi consist of long, filamentous cells called hyphae. Fungi grow best in warm, damp, and humid conditions, and spread and reproduce by budding or making small reproductive bodies called spores. Several fungi are pathogens, meaning that they can infect humans and cause disease. Well-known examples include Athlete's foot and ringworm. Fungal infections are also called mycoses or mycotic infections. According to the Centers for Disease Control (CDC), these infections pose a growing threat to public health, because, in recent years, they have surged in persons having an immune system impaired by disease, as for example, by AIDS , or treatment (immunocompromised). The CDC also notes that, increasingly, previously harmless environmental fungi that live in soil, on plants, in compost heaps, or on rotting food, are causing infections in humans. Infections caused by fungi found in the environment that can infect both people and animals are called zoonotic infections. Examples are aspergillosis and histoplasmosis, infections that affect lungs.

Fungal infections can be superficial or systemic. Superficial infections commonly affect the skin or mucous membranes. They can be mild, only affecting the outer layer of the skin (epidermis), or extend to deeper skin layers, or to the hair and under nails. Infections that extend to even deeper tissues and muscle are called subcutaneous infections. These fungi are often called dermatophytes. Dermatophytes that infect human hosts are referred to as anthropophilic, and develop most commonly on body areas continually exposed to warm, moist environments, such as shoes and bathroom or public bath floors. The infection is commonly transmitted through direct contact with an infected person, but the organisms are also found on infected skin scales or hair in combs, hair brushes, clothing, furniture, theatre seats, caps, bed linens, towels, rugs, and socks. Depending on the species, fungi may survive in the environment as long as 15 months. The risk of fungal infection is increased in those with skin injuries, such as cuts, burns, or abrasions. A fungal infection may also be caused by more than one fungus species.

Systemic fungal infections result from inhalation of airborne fungal spores. These infections can affect the entire body and most often occur in immunocompromised persons. An example is fungal meningitis , caused by the Cryptococcus fungus, that causes inflammation of the membranes covering the brain and spinal cord. It is one of the most common life—threatening fungal infections diagnosed in HIV patients.

Demographics

Accurate data concerning fungal infections are difficult to obtain because reporting requirements vary considerably and because they are also misdiagnosed, or not diagnosed because they occur as a result of a preexisting illness. Available data suggests that fungal infections are on the rise, due to factors such as the human immunodeficiency virus (HIV) epidemic, increased organ transplantations and chemotherapy , and the increasing use of invasive procedures for treatment and life support interventions. Worldwide, the incidence of specific fungal infections varies significantly since they are often caused by fungi that reside in nature and vary considerably in their geographical distribution. According to the CDC, aspergillosis is believed to affect 1–2 persons per 100,000. Positive histoplasmosis skin tests are recorded in as many as 80% of the people living in areas where the Histoplasma capsulatum fungus is common, such as the eastern and central United States. Infants, young children, and older persons, in particular those with chronic lung disease are at increased risk for severe infection.

Superficial fungal infections are among the most common skin diseases, affecting millions of people throughout the world, especially in the tropics and subtropics. Vaginal yeast infections are also very common. According to the national Institutes of Health (NIH), approximately 75% of women have a yeast infection during their lives with 50% of women having two or more infections. Twelve to 15% of men also develop symptoms after sexual contact with an infected partner.

A new area of public health concern is the increase of superficial and deep fungal infections during the past decade in hospitals. In a study covering 115 hospitals over the 1980–1990 period, the CDC reported that the rate of fungal infections nearly doubled, increasing from 2.0 to 3.8 per 1,000 patients discharged. Another area of concern is the growing emergence of fungi previously unrecognised as being pathogens.

Causes and symptoms

The most common fungal infections are caused by dermatophytes that belong to three genera of fungi:

• Epidermophyton, which consists of two species, only one being a pathogen, namely Epidermophyton floccosum.
• Microsporum, with 19 species of which 9 are involved in human or animal infections.
• Trichophyton, with 22 species, most causing infections in humans or animals.

These organisms have the ability to sprout thread-like hyphae that cling to the superficial layer of the skin. In response to this fungal invasion, the skin increases its production of skin cells. As these cells push to the surface, the skin thickens and becomes scaly.

Tinea is the name given to fungal skin infections caused by Trichophyton fungi. These infections derive their names from the area of the body affected. Some common tinea infections include:

• Ringworm. This infection derives its name from the red spots that form and grow into large rings on the skin. It is called tinea corporis. When it affects the scalp, it is known as tinea capitis.
• Athlete's foot. This infection is called tinea pedis, and it affects the skin of the feet, particularly between the toes, which becomes itchy and red.
• Nail fungus. When the fungus infects nail beds, it is called tinea unguium. The infection affects toenails more than fingernails because toenails are often confined in the dark, warm, moist environment provided by shoes. Infected nails are brittle, distorted in shape, often with a dull, yellowish or dark color.
• Jock itch. This infection is called tinea cruris and affects the moist area of the groin. It has an itchy spreading red border, and tends to affect men more than women.

albicans. The organism is harmless in healthy persons. However, it can multiply and cause infections in immunocompromised persons, or as a result of some metabolic imbalance. Yeast infections, also called candidiasis, can affect all parts of the body. When the mouth is affected, white patches form in the oral cavity and the infection is called thrush. It can also affect the esophagus (esophagitis), and in women, the vagina, where it irritates the area around the vagina called the vulva. Symptoms are burning sensations, redness, and swelling of the vagina and vulva, vaginal discharge, and pain when urinating.

Other fungal infections can be zoonotic, as for example:

• Aspirgillosis, caused by Aspirgillus fumigatus, a fungus that occurs all over the environment. Animal hosts are birds and they can transmit the infection to humans, for example to farmers or bird handlers. Symptoms are usually respiratory.
• Histoplasmosis, caused by Histoplasma capsulatum. Common hosts are birds and bats. The infection primarily affects the lungs.

Diagnosis

If the fungal infection affects only the skin, the treating physician will first determine if symptoms are caused by a fungus or by another skin condition, such as dermatitis or psoriasis , which have very different treatments. A microscope examination of a skin or scalp sample is usually sufficient to confirm diagnosis. Otherwise, the sample may be sent to a lab to grow the fungus in a test tube and identify the exact species of fungus causing the infection.

Treatment

Several medications are available to treat superficial fungal infections. These antifungal medications may be applied directly to the fungal infection site on the skin or other surface, such as the vagina or the inside of the mouth. They may also be taken by mouth or injected when needed to treat more serious infections.

Treatment of systemic fungal infections depends on the specific organism responsible for infection, the site and the severity of the infection, as well as the extent of immunosuppression in the patient.

Nutrition/Dietetic concerns

Some nutrition experts believe that fungi, like bacteria, thrive on sugar, and that excessive fruit in the diet may provide them with the sugar they require for growth. Nutritionists accordingly point out that a well-balanced diet can also prove beneficial to maintain fungal infection resistance.

QUESTIONS TO ASK YOUR DOCTOR

• Can my fungal infection be cured?
• Will it come back?
• Are complications possible?
• How serious can side effects be from oral antifungal medications?
• How long will treatment take?
• How can I best protect family and friends from infection?

Therapy

Tinea infections can be treated by a variety of different medications. For tinea pedis, cruris, and corporis, antifungal creams (Lamisil, Micatin) are available over the counter at a pharmacy. Prescription antifungal medications are stronger, faster and require fewer applications. In some resistant cases, oral medications are required. They include griseofulvin (Grispeg, Fulvicin), terbinafine (Lamisil), itraconazole (Sporonox), and fluconazole (Diflucan). Tinea capitis, tinea unguium and chronic tinea pedis are difficult to eradicate completely and require oral treatment.

Candida infections are commonly treated with a topical antifungal medication, such as butoconazole, clotrimazole and nystatin. Oral fluconazole can be used to treat resistant or recurring cases of vaginal infection.

Systemic fungal infections are treated with amphotericin B, despite its toxicity side effects, but new formulations are in development. In 2001, two new antifungal drugs were approved by the FDA, caspofungin and voriconazole.

Prognosis

Most healthy people can resist fungal infections. However, this is not the case for immunocompromised persons. Resistant infections are also very difficult to treat with the currently available medications and there is a strong tendency for fungal infections to happen again in many people even after effective clearing with medication. Oral medications are the most effective antifungals, but they can also cause dangerous side effects, including heart and liver failure. Cure rates range between 40% and 90%, but of people successfully treated with oral antifungals, 15% to 20% develop another infection in the following year.

KEY TERMS

AIDS —Acquired immune deficiency syndrome. AIDS is caused by the human immunodeficiency virus, or HIV.

Antifungal —A drug that treats infections caused by fungi.

Dermatitis —Inflammation of the skin, either caused by direct contact with an irritating substance, or an allergic reaction.

Dermatophyte —Any of various fungi that can cause parasitic skin infections.

Epidermis —The outer protective layer of the skin.

Esophagus —The tube that leads from the throat to the stomach.

Eukaryotic —A cell with a distinct membrane—bound nucleus.

Fungus —Any of numerous eukaryotic organisms of the kingdom Fungi, which lack chlorophyll and vascular tissue and can be single—celled or have a body mass of branched filamentous threads that often produce specialized fruiting bodies. The kingdom includes the yeasts, molds, smuts, and mushrooms.

Genus —A category ranking below a family and above a species and generally consisting of a group of species. Pl.: genera.

Immune system —The organs and cells that defends the body against infections and other diseases.

Immunocompromised —Having an immune system that has been impaired by disease or treatment.

Mold —Parasitic, microscopic fungus with spores that float in the air like pollen.

Mycosis —An inflammatory condition caused by a fungus. Pl.: mycoses.

Mycotic disease —Diseases caused by fungi.

Mycotoxins —A diverse class of poisonous compounds produced by certain mushrooms and other fungi.

Pathogen —A disease—causing microorganism.

Psoriasis —A chronic disease of the skin believed to be genetic and consisting of itchy, dry, red patches, usually affecting the scalp or arms and legs.

Spore —A small, usually single—celled reproductive body that can grow into a new organism, produced especially by certain bacteria, fungi, and non-flowering plants.

Thrush —Yeast infection (candidiasis) of the oral cavity.

Zoonotic diseases —Diseases shared by animals and humans.

Prevention

Superficial fungal infections can be prevented by minimizing the possibility for a fungus to grow. This is best achieved by keeping vulnerable body areas clean and dry. For instance, the groin and feet should be washed daily, ensuring that the web spaces between the toes are carefully dried. Wearing cotton socks and open-toed sandals also keep the feet dry. In locker rooms and swimming pools, an antifungal foot powder can be used after showering. Towels, combs, and head wear should never be shared. Nails should be cleaned daily and kept trimmed and clipped.

Caregiver concerns

Fungal infections are becoming an increasing problem in older adults, due to increased travel and leisure activities in areas that are endemic for these fungi. This age group is also more likely to require care in an intensive care unit, and undergo invasive procedures which contributes to a higher risk of fungal infection.

Resources

BOOKS

Kauffman, Carol, A., and Gerald L. Mandell, editors. Atlas of Fungal Infection. 2nd ed., Philadelphia, PA: Current Medicine LLC, 2006.

Magan, N., Olsen, M. Mycotoxins in Food: Detection and Control. Boca Raton, FL: CRC Press, 2004.

Richardson, Malcom, and Elizabeth Johnson. Pocket Guide to Fungal Infection. 2nd ed., New York, NY: Wiley-Blackwell, 2006.

Richardson, Malcom, and David W. Warnock. Fungal Infection: Diagnosis and Management. 3rd ed., New York, NY: Wiley-Blackwell, 2003.

Suhonen, Raimo E., Rodney P. R. Dawber, and David H. Ellis. Fungal Infections of the Skin and Nails. London, UK: Informa Healthcare, 1999.

PERIODICALS

Jacobs, L. G. “Fungal urinary tract infections in the elderly: treatment guidelines.” Drugs and Aging 8, no. 2 (February 1996): 89–96.

Kauffman, C. A. “Fungal infections in older adults.” Clinical Infectious Diseases 33, no. 4 (August 2001):550–555.

Kauffman, C. A., and S. A. Hedderwick. “Treatment of systemic fungal infections in older patients: achieving optimal outcomes.” Drugs and Aging 18, no. 5 (2001):313–323.

Loo, D. S. “Cutaneous fungal infections in the elderly.” Dermatologic Clinics 22, no. 1 (January 2004): 33–50.

Martin, E. S., and B. E. Elewski. “Cutaneous fungal infections in the elderly.” Clinical Geriatric Medicine 18, no. 1 (February 2002): 59–75.

OTHER

Fungal Infections. Penn State, Health & Disease Information (March 08, 2008). http://www.hmc.psu.edu/healthinfo/f/fungalinfection.htm.

Fungal Infections of Fingernails and Toenails. American Academy of Family Physicians, Familydoctor Website. http://familydoctor.org/online/famdocen/home/common/infections/common/fungal/663.html.

Fungus Infections: Preventing Recurrence. AOCD, Information Page. (March 08, 2008). http://www.aocd.org/skin/dermatologic_diseases/fungus_preventing.html.

Mycotic Disease Listing. CDC Information Sheet. (March 08, 2008). http://www.cdc.gov/ncidod/dbmd/mdb/diseases.htm.

Protect Yourself from Mold. CDC Information page. June 07, 2007. (March 08, 2008). http://www.bt.cdc.gov/disasters/mold/protect.asp.

Tinea Infections: Athlete's Foot, Jock Itch and Ringworm. American Academy of Family Physicians, Family doctor Website. (March 08, 2008). http://familydoctor.org/online/famdocen/home/common/infections/common/fungal/316.printerview.html.

ORGANIZATIONS

American Osteopathic College of Dermatology (AOCD), 1501 East Illinois St., P.O. Box 7525, Kirksville, MI, 63501, (660) 665-2184, (800) 449-2623, (660) 627-2623, info@aocd.org, http://www.aocd.org.

Centers for Disease Control and Prevention (CDC)—Division of Foodborne, Bacterial and Mycotic Diseases (DFBMD), 1600 Clifton Road NE, MS-C09, Atlanta, GA, 30333, (404) 498-1515, (800) 311-3435, http://www.cdc.gov/nczved/dfbmd.

National Institute of Allergy and Infectious Diseases (NIAID), 6610 Rockledge Drive, MSC 6612, Bethesda, MD, 20892-6612, (301) 496-5717, (866) 284-4107, http://www3.niaid.nih.gov.

Monique Laberge Ph.D.

Fungal Infections

What Are Fungal Infections?

What Are the Common Signs and Symptoms of Fungal Infections?

What Are Some Specific Fungal Infections?

How Common Are Fungal Infections?

Are They Contagious?

How Do Doctors Make the Diagnosis?

Can Fungal Infections Be Treated?

Can Fungal Infections Be Prevented?

Resources

Fungal (FUNG-gul) infections are caused by fungi (FUNG-eye) that can grow on the skin, nails, and hair and within internal organs.

KEYWORDS

for searching the Internet and other reference sources

Aspergillosis

Blastomycosis

Candidiasis

Coccidioidomycosis

Cryptococcosis

Fungi

Histoplasmosis

Molds

Mycoses

Mycology

Sporotrichosis

Tinea

Yeasts

What Are Fungal Infections?

Fungal infections are caused by fungi, tiny microbes* found in soil, air, and water, as well as on plants, animals, and people. There are at least 100,000 species of fungi. The most familiar types are the mushrooms that some people like to eat on pizza, the fuzzy white or blue-green mold that grows on forgotten foods in the back of the refrigerator, and the mildew on the shower curtain. Fungi grow best in warm, moist areas, like a steamy bathroom or the spaces between the toes.

*microbes

(MY-krobes) are microscopic living organisms, such as bacteria, viruses and fungi.

Relatively few species of fungi cause fungal infections, also called mycoses (my-KO-seez). Those that produce infection can cause two basic types: superficial and systemic infections. Superficial infections are found on the skin, nails, or hair and usually are not serious. Systemic infections take hold inside the body, in individual organs or throughout the body, and can be severe. Systemic infections are more likely to appear in people who have weak immune systems, such as those who have cancer or AIDS*. In these people, the infections can cause chronic* disease and, in some cases, death.

*AIDS ,

or acquired immunodeficiency (ih-myoo-no-dih-FIH-shen-see) syndrome, is an infection that severely weakens the immune system; it is caused by the human immunodeficiency virus (HIV).

*chronic

(KRAH-nik) means continuing for a long period of time.

What Are the Common Signs and Symptoms of Fungal Infections?

Superficial fungal infections, such as jock itch, vaginal yeast infection, athlete’s foot, and ringworm, typically are annoying but not very serious. Their symptoms generally include itchy, dry, red, scaly, or irritated skin. Systemic fungal infections often begin in the lungs and take time to develop. Severe infections occur in people whose immune systems have been weakened, allowing the infection to spread beyond the lungs to other organs. Symptoms of systemic fungal infections depend on which organs become infected and may include respiratory problems, extreme tiredness, coughing, weight loss, fever, night sweats, and headache.

What Are Some Specific Fungal Infections?

Tinea (TIH-nee-uh) is a general term given to a group of superficial fungal infections that affect the nails, feet (athlete’s foot), groin area (jock itch), scalp, or skin (ringworm). Trichophyton and Microsporum fungi cause these related infections. Ringworm is identified by a red, scaly patch on the skin that looks like an expanding ring around a clearing center. Symptoms of athlete’s foot include redness and cracking of the skin between the toes, and infected nails on the hands or feet usually look white and appear to be crumbling.

Candidiasis (kan-dih-DYE-uh-sis) is a superficial fungal infection caused by various strains of Candida (CAN-dih-duh) fungi. Candida is a yeastlike fungus often found in the mouth and the lining of the intestinal tract of healthy people. In people with weak immune systems, however, it can grow out of control, leading to an infection. A Candida infection of the mouth and throat is known as oropharyngeal (or-oh-fair-in-JEE-ul) candidiasis (OPC) or thrush, and infection of the vagina is known as vulvovaginal (vul-vo-VAH-jih-nul) candidiasis (VVC) or vaginal yeast infection. OPC can affect newborns, people with AIDS or diabetes*, and other people with weak immune systems. Its symptoms include white, thick patches on the tongue, mouth, and throat. Candida infection commonly occurs in newborns in the form of thrush or diaper rash. VVC is associated with vaginal burning or itching and a thick, cheeselike discharge. In certain situations, Candida can enter the bloodstream and spread to internal organs. This is seen most frequently in hospitalized patients who have weak immune systems and have received antibiotics.

*diabetes

(dye-uh-BEE-teez) is a condition in which the body’s pancreas does not produce enough insulin or the body cannot use the insulin it makes effectively, resulting in increased levels of sugar in the blood. This can lead to increased urination, dehydration, weight loss, weakness, and a number of other symptoms and complications related to chemical imbalances within the body.

A yeast colony, as seen with an electron microscope, looks like growing vegetation. Custom Medical Stock Photo, Inc.

Aspergillosis (as-per-jih-LO-sis) is the name for a variety of systemic infections caused by Aspergillus (as-per-JIH-lus) fungi. If it is inhaled through the mouth or nose, the fungus can cause a mild allergic reaction or a more serious infection of the sinuses* and lungs. Symptoms of aspergillosis vary and may include fever, cough, chest pain, and wheezing. In severe cases, typically seen in people with weak immune systems, the infection can spread to other organs, including the brain, skin, and bones.

*sinuses

(SY-nuh-ses) are hollow, air-filled cavities in the facial bones.

Blastomycosis (blas-toh-my-KO-sis) is a systemic infection caused by the Blastomyces dermatitidis fungus commonly found in soil in the southeastern, midwestern, and south-central United States. The disease’s symptoms resemble those of the flu: joint and muscle pain, a cough that brings up sputum*, fever, chills, and chest pain. If it progresses, it can lead to chronic pulmonary* infection, causing permanent lung damage, or widespread disease that affects the bones, skin, and genital and urinary tracts. Blastomycosis leads to death in about 5 percent of patients.

*sputum

(SPYOO-tum) is a substance that contains mucus and other matter coughed out from the lungs, bronchi, and trachea.

*pulmonary

means referring to or pertaining to the lungs.

Cryptococcosis (krip-toh-kah-KO-sis) is a systemic infection caused by the fungus Cryptococcus neoformans, usually found in soil or bird droppings. Typically, the fungus enters the body through the mouth or nostrils when someone inhales fungi spores*, and symptoms of a lung infection, such as cough and chest pain, may develop. Although infection with Cryptococcus usually produces no symptoms or only mild symptoms in healthy people, the infection may spread in people who have weak immune systems. If it spreads to the central nervous system, it can cause inflammation of the membranes covering the brain and spinal cord. This is especially common among people with AIDS.

*spores

are a temporarily inactive form of a germ enclosed in a protective shell.

Histoplasmosis (his-toh-plaz-MO-sis) is usually a mild systemic infection caused by Histoplasma capsulatum. This fungus is found in the eastern and central United States in soil that contains bird and bat feces*. When the soil is disturbed, the fungal spores may be inhaled. Histoplasmosis can cause flulike symptoms, including body aches, fever, and cough. Most people who become infected do not experience symptoms, but as with other fungal infections, people with weak immune systems are at risk for severe disease. In those cases, the infection affects the lungs and may spread to the liver*, spleen*, bones, and brain.

*feces

(FEE-seez) is the excreted waste from the gastrointestinal tract.

*liver

is a large organ located beneath the ribs on the right side of the body. The liver performs numerous digestive and chemical functions essential for health.

*spleen

is an organ in the upper left part of the abdomen that stores and filters blood. As part of the immune system, the spleen also plays a role in fighting infection.

Sporotrichosis (spo-ro-trih-KO-sis) is a skin infection caused by the Sporothrix schenckii fungus, which is found in soil, thorny plants, hay, sphagnum (SFAG-num) moss, and other plant materials. It enters the skin through a small cut or puncture, such as a thorn might make. Soon, small reddish bumps resembling boils* form around the cut and often ulcerate*. In some cases, infection can spread to other parts of the body, such as the lungs or joints.

*boils

are skin abscesses, or collections of pus in the skin.

*ulcerate

means to become eroded by infection, inflammation, or irritation.

Friendly Bacteria

Naturally occurring “friendly” bacteria and fungi live side by side on the human body. Some bacteria help keep fungi in check by preventing them from reproducing uncontrollably and causing disease. From time to time, however, doctors need to prescribe antibiotics to combat not-so-friendly bacteria that cause illness. Most antibiotics kill many types of bacteria, both good and bad, and using them for long periods of time can destroy too many friendly bacteria, allowing fungi to grow unchecked and eventually cause infection. To preserve the bacteria we need, it is important to use antibiotics only when necessary and prescribed by a doctor.

Coccidioidomycosis (kok-sih-dee-oyd-o-my-KO-sis) is a systemic infection caused by Coccidioides immitis, a fungus found in soil in the southwestern United States, Mexico, and South America. Most people with coccidioidomycosis have no symptoms, but 40 percent of patients experience a flulike illness, with fever, rash, muscle aches, and cough. Also know as valley fever, the infection can cause pneumonia* or widespread disease affecting the skin, bones, and membranes covering the brain and spinal cord.

*pneumonia

(nu-MO-nyah) is inflammation of the lung.

How Common Are Fungal Infections?

Superficial fungal infections, such as athlete’s foot and candidiasis, are fairly common. Systemic infections, on the other hand, are rare, appearing in less than one to two people of every 100,000 in the United States, according to the U.S. Centers for Disease Control and Prevention. They are more common in certain populations, such as people with AIDS or those who have had organ transplants.

With the so-called endemic* mycoses, rates of disease are higher in specific geographic areas. For example, coccidioidomycosis occurs in about 15 of every 100,000 people in parts of the southwestern United States (with 10 to 50 percent of the population testing positive for exposure to the fungus). In areas where histoplasmosis is found, up to 80 percent of the population test positive for exposure to Histoplasma capsulatum, but the disease develops only in people with weak immune systems.

*endemic

(en-DEH-mik) describes a disease or condition that is present in a population or geographic area at all times.

Are They Contagious?

Some fungal infections, such as candidiasis and ringworm, can spread from person to person through contact with the infected area. Most infections, however, develop from fungi found naturally on the human body or in the environment. Many fungi that cause systemic respiratory disease are found in soil or in the droppings of animals or birds. Usually they are inhaled after the soil or droppings are disturbed, sending dust and fungal spores into the air.

How Do Doctors Make the Diagnosis?

Most superficial fungal infections are diagnosed based on their appearance and location. A doctor also may take a skin scraping to examine under the microscope or to culture* in a laboratory. Some fungi glow with a particular color under ultraviolet light, so a doctor may make the diagnosis by shining such a light on the affected area. Systemic infections can be diagnosed by collecting a sample of blood, urine, cerebrospinal fluid*, or sputum to culture.

*culture

(KUL-chur) is a test in which a sample of fluid or tissue from the body is placed in a dish containing material that supports the growth of certain organisms. Over time, ranging from hours to weeks, the organisms will grow and can be identified.

*cerebrospinal

(seh-ree-bro-SPY-nuhl) fluid is the fluid that surrounds the brain and spinal cord.

Can Fungal Infections Be Treated?

Most superficial fungal infections are treated at home with antifungal creams or shampoos for 1 to 2 weeks. Oral (taken by mouth) antifungal medication also may be prescribed, if necessary. Some cases of fungal infection last for a while and may need to be treated with medicine for 2 to 4 weeks or even longer. Systemic illnesses often require hospitalization so that the patient can receive intravenous* antifungal drugs and supportive care.

*intravenous

(in-tra-VEE-nus) means within or through a vein. For example, medications, fluid, or other substances can be given through a needle or soft tube inserted through the skin’s surface directly into a vein.

Can Fungal Infections Be Prevented?

Preventing fungal infections can be difficult, because fungi are everywhere. In general, people who are otherwise healthy rarely contract systemic fungal infections. Practicing good hygiene, keeping the skin dry, and changing socks and underwear every day can help prevent superficial skin infections.

See also

Coccidioidomycosis (Valley Fever)

Skin and Soft Tissue Infections

Resources

Organization

U.S. Centers for Disease Control and Prevention (CDC), 1600 Clifton Road, Atlanta, GA 30333. The CDC provides fact sheets and other information on fungal infections through its website.

Telephone 800-311-3435 http://www.cdc.gov

Website

KidsHealth.org. KidsHealth is a website created by the medical experts of the Nemours Foundation and is devoted to issues of children’s health. It contains articles on a variety of health topics, including fungal infections.

http://www.KidsHealth.org

Fungal infections

Definition

Fungi are types of parasitic plants that include molds, mildew, and yeast. A fungal infection is an inflammatory condition in which fungi multiply and invade the skin, the digestive tract, the genitals, and other body tissues, particularly, the lungs and liver. Fungal infections of the skin are often called ringworm or tinea.

Description

Microscopic fungi, which are called dermatophytes, often live exclusively on such dead body tissues as hair, the outer layer of the skin, and the nails. The fungus grows best in moist, damp, dark places with poor ventilation and on skin that is irritated, weakened, or continuously moist. Superficial fungal infections include tinea capitis, an infection of the neck and scalp; tinea barbae, also called barber's itch, along the beard area in adult males; tinea corporis on parts of the body, such as the arms, shoulders, or face; tinea cruris, or jock itch , involving the groin; tinea pedis, or athlete's foot ; tinea versicolor; and tinea unguium, or infection of the nails. The term tinea gladiatorum is sometimes used to describe ringworm infections in atheletes. Tinea gladiatorum is most common in swimmers, wrestlers, and athletes involved in other contact sports. Fungal infections of the skin and nails are very common in children, but they can affect all age groups.

Systemic fungal infections occur when spores are touched or inhaled, or there is an overgrowth of fungi in or on the body. Such infections are most often a serious problem in those with suppressed immune systems. Candidiasis is a rather common fungal infection. When it occurs in the mouth, it is called thrush. Less often, it occurs in the mucous membranes of other parts of the digestive system, or in the vagina, heart valves, urinary tract, eyes, or blood. Other systemic fungal infections include aspergillosis, which mostly affects the lungs and may also spread to the brain and kidneys; blastomycosis, a lung infection that may spread through the bloodstream; coccidioidomycosis, also known as San Joaquin or valley fever ; mucormycosis, which can develop into a very serious, life-threatening infection; and histoplasmosis.

Causes & symptoms

Fungi are widespread in the environment, so it is not unusual that a certain amount of fungi and their spores end up being inhaled into the lungs or landing on the skin. Under conditions of moisture, warmth, irritation, or injury, these fungi grow rapidly and may cause illness. Superficial fungal infections may be due to an overgrowth of fungi already present, or the infection may be the result of contact with an infected person or with contaminated surfaces, bed sheets, towels, or clothing. Fungal infections can be spread from one part of the body to another by scratching or touching. Additionally, tinea unguium infections

have been linked to the use of methyl methacrylate, a glue used for attaching acrylic fingernails.

Fungal spores are often present in soil and are likely to be inhaled when the soil is dug up or otherwise disturbed. Systemic fungal infections are commonly contracted in this way. In addition, fungi that normally inhabit the intestines, such as Candida albicans, may multiply, causing an infection due to an overgrowth of the fungi.

Tinea infections usually cause itchy, red, scaly, ring-shaped patches on the skin that spread easily. Hairs in the area of infection often fall out or break off, and the skin may crack. The skin may also develop a secondary bacterial infection. In tinea unguium, the nails discolor, crack, and thicken. Tinea versicolor may cause pigment changes in the skin that persist for up to a year.

Systemic fungal infections develop slowly. Symptoms often may be nonexistent, or there may be only the feeling of having a cold or the flu. Coughing, a fever, chest pain, chills , weight loss, and difficulty with breathing may become evident. Additional symptoms depend on the type and site of the infection.

Fungal infections are more common and more severe in people taking antibiotics, corticosteroids, immunosuppressant drugs, and contraceptives. This is also the case in people with endocrine disorders, immune diseases, and other conditions such as obesity, AIDS, tuberculosis , major burns, leukemia , and diabetes mellitus . Fungal infections often occur due to the use of antibiotic drugs for other conditions, because antibiotics kill off the bacteria that normally keep fungi at bay.

Diagnosis

Fungal infections of the skin, hair, and nails often can be diagnosed based on the characteristic appearance of affected areas. A KOH (potassium hydroxide) prep is a simple laboratory test to confirm the diagnosis. The test uses tissue samples treated with a 20% potassium hydroxide solution to detect fungi. Examining the skin with a Wood's ultraviolet lamp is another easy and convenient method to determine the presence of a fungus. Culture and sensitivity testing can be used if a more definitive diagnosis is required. Systemic fungal infections may be initially diagnosed from blood tests. Confirmation is determined by cultures made from sputum, blood, urine, bone marrow, or infected tissue samples.

Treatment

Among the herbs that slow down or halt the growth of fungus are goldenseal (Hydrastis canadensis ), myrrh (Commiphora molmol ), garlic (Allium sativa ), pau d'arco (Tabeebuia impestiginosa ), turmeric (Curcuma longa ), oregano (Origanum vulgare ), cinnamon (Cinnamonum zeylanicum ), jewelweed, sage (Salvia officinalis ), Impatiens aurea, yellow dock (Rumex crispus ), the lichen known as old man's beard (Usnea barbata ), black walnut husks and bark (Juglans nigra ), licorice (Glycyrrhiza glabra ), and Calendula officinalis. These herbs can be applied to external fungus as infusions, salves, powders, or vinegars. Many of them can also be taken internally as capsules or tinctures. Antifungal herbs can be quite strong, however, and care should be taken that a given remedy is suitable for internal use.

When an infusion is used, the affected area should be washed or soaked in the herbal water for at least 15 minutes twice daily. Store-bought or homemade tea bags can be soaked in water or vinegar for about 10 minutes and then used as a poultice for the same effect. Herbal vinegars make excellent remedies for fungus, as vinegar is in itself antifungal. "Gourmet" vinegars with such antifungal ingredients as oregano and garlic are often readily available at grocery stores. The vinegar can be applied a few times daily with cotton or compresses. In addition, a bentonite clay dusting powder can be useful for drying out the environment of moist skin in which fungus thrives. It works best when mixed with powdered antifungal herbs such as myrrh or goldenseal. Dusting powder is especially helpful for athlete's foot.

Many herbs high in essential oils also have antifungal action, particularly tea tree (Melaleuca alternifolia ), oregano, lavender (Lavandula officinalis ), Eucalyptus spp., rose geranium (Pelargonium graveolens ), peppermint (Mentha piperita ), chamomile (Matricaria recutita ), and myrrh. Peppermint oil is especially helpful in relieving the itching associated with many fungal infections. The simplest way to use aromatherapy to fight fungal infections is to add several drops of any single essential oil or combination of oils to bathwater. Essential oil can also be added to mixtures for soaking or compresses. Tea tree is the herb most frequently recommended for the treatment of superficial fungal infections. As with all essential oils, the full-strength oil should be diluted in a carrier. A dilution of tea tree oil can be made by adding the essential oil to a carrier oil. This mixture can be added directly to the site of a skin infection.

A healthy diet should be maintained. Foods that are high in yeast, such as beer and wine, breads, and baked goods should be avoided. Fermented foods and sugary foods, including honey and fruit juices, should also be avoided until symptoms have cleared. Antifungal culinary herbs such as garlic, tumeric, oregano, sage, and cinnamon should be used liberally in foods. Yogurt containing live cultures can be incorporated into the diet to supply needed gut bacteria, and help reduce digestive infections such as candidiasis and thrush. Lactobacillus acidophilus and Lactobacillus bulgaricus can also be taken directly as supplements.

Supplements that can be taken for fungal infections include vitamins A, B complex, C, and E. Caprylic acid, an extract of the coconut plant, is also recommended as an antifungal, as well as grapefruit seed extract . Essential fatty acids , contained in evening primrose oil , fish liver oil, or flaxseed oil, can help reduce the inflammation of systemic or superficial fungal infections. A dose of one of these oils is recommended as a daily supplement.

Allopathic treatment

Superficial fungal infections are usually treated with such antifungal creams or sprays as tolnaftate (Aftate or Tinactin), clotrimazole, miconazole nitrate (Micatin products), econazole, ketoconazole, ciclopirox, naftifine, itraconazole, terbinafine, fluconazole, or Whitfield's tincture made of salicylic acid and benzoic acid. If the infection is resistant, a doctor may prescribe an oral antifungal drug such as ketoconazole or griseofulvin. Drugs used for systemic infections include amphotericin B, which is highly toxic and is used for severe or life-threatening infections; the azoles, particularly fluconazole and itraconazole, which have been found to be the least toxic of these medications; and flucytosine alone or in combination with other antifungal medications. Fungal infections that become inflamed may be treated with a combination antifungal/steroid medication. Certain infections may require surgery.

Expected results

Infections usually respond to treatment within several weeks. However, many fungal infections are resistant to treatment, and it may take an extended time and repeated treatments to effect a cure. Infections may spread, and secondary bacterial infections may develop. Medications for fungal infections are often strong, and their use may cause such undesirable side effects as headache, dizziness, nausea, vomiting , or abdominal pain. Fungal infections are usually not serious in otherwise healthy individuals. However, a systemic fungal infection may be severe and life-threatening for those with compromised immune systems.

Prevention

Good personal hygiene should be maintained. In the case of superficial infections, the skin should be kept clean and dry, and care should be taken to avoid contact with other parts of the body. If someone in the household has a superficial fungal infection, bed sheets, towels, floors, shower stalls, and other contact surfaces should be washed with hot water and disinfected after use.

Resources

BOOKS

Duke, James A., Michael Castleman, and Alice Feinstein. The Green Pharmacy. Emmaus, PA: Rodale Press, 1997.

PERIODICALS

Farschian, M., R. Yaghoobi, and K. Samadi. "Fluconazole Versus Ketoconazole in the Treatment of Tinea Versicolor." Journal of Dermatologic Treatment 13 (June 2002): 73-76.

Kohl, T. D., et al. "Tinea gladiatorum: Pennsylvania's Experience." Clinical Journal of Sports Medicine 12 (May 2002): 165-171.

Lipozencic J., M. Skerlev, R. Orofino-Costa et al. "A Randomized, Double-Blind, Parallel-Group, Duration-Finding Study of Oral Terbinafine and Open-Label, High-Dose Griseofulvin in Children with Tinea Capitis Due to Microsporum Species." British Journal of Dermatology 146 (May 2002): 816-823.

Weinstein, A., and B. Berman. "Topical Treatment of Common Superficial Tinea Infections." American Family Physician 65 (May 15, 2002): 2095-2102.

ORGANIZATIONS

American Academy of Dermatology. 930 East Woodfield Rd., PO Box 4014, Schaumburg, IL 60168. (847) 330-0230. <www.aad.org>.

OTHER

drkoop.com Medical Encyclopedia. "Ringworm." http://www.drkoop.com/conditions/ency/article/001439.htm.

Merck & Co., Inc. The Merck Manual of Diagnosis and Therapy. http://www.merck.com/pubs/mmanual/section10/chapter113/113a.htm.

Merck & Co., Inc. The Merck Manual of Diagnosis and Therapy. http://www.merck.com/pubs/mmanual/section13/chapter158/158a.htm.

Patience Paradox

Rebecca J. Frey, PhD

FUNGAL INFECTIONS

Fungal infections of the skin are among today's most common infectious diseases, and they occur worldwide. Superficial fungus infections fall into three broad categories: the dermatophytes (ringworm), tinea versicolor, and cutaneous candidiasis (yeast infection).

Tinea Corporis (Ringworm of the Skin). The typical lesion is an itchy, round or oval patch of skin with central clearing and a red scaly margin— hence the name "ringworm." If it occurs in the groin, it is called "jock itch" or "tinea cruris." If there are only two or three rings of infection, topical therapy with antifungal creams will be sufficient. For widespread infection, oral antifungal pills may be necessary.

Tinea Capitis (Fungal Infection of the Hair). Fungal infections of the scalp are most common in children. The infection presents as round scaly patches of hair loss, often with broken-off stubbly hairs. The infection must be treated with oral antifungal therapies. The prognosis is excellent and shaving the scalp is not necessary.

Tinea Pedis (Fungus of the Feet, or Athlete's Foot). Tinea pedis is the most common type of fungal infection, presenting as itchy, scaling, and/or macerated webspaces. There may be a powdery white scaling of the bottom of the feet. Sometimes the infection presents as blisters on the bottom of the feet. The infection can spread to the groin (tinea cruris). Topical antifungals will cure the webspace infections but oral antifungals are necessary to treat the blistering infections. Afflicted individuals should keep their feet dry and spray their shoes with antifungal sprays.

Tinea of the Nails (Onychomycosis). Toenails are more commonly affected than fingernails. The nail becomes opaque, yellowish, thickened, and crumbly with the accumulation of material under the nail. There may be an associated athlete's foot infection. Oral antifungals are necessary to cure the problem.

Candidiasis (Yeast Infections). Yeast infections occur in closed spaces on the skin, such as the corner of the mouth, under breasts, in armpits, and in the groin. It is a red, moist, and often odorous tender rash, and is more severe in patients taking antibiotics or who have systemic diseases such as diabetes. Heat and sweat aggravate the problem. Candidiasis can also occur in the mouth (oral thrush) or as a yeast vaginitis. Treatment is with topical antiyeast creams and/or oral medication. To prevent recurrence, the area must be kept dry.

Tinea Versicolor. Tinea versicolor presents on the upper trunk—as brown spots in the winter and white spots in the summer. It is easily treated by washing the area with antidandruff shampoos, but the therapy must be repeated monthly to prevent recurrence.

Susan Swiggum

John Adam