Allergy shots

Definition

Allergy shots, also called immunotherapy, are a form of treatment that reduces a person's allergic reaction to a particular allergen. Allergy shots can reduce symptoms of allergic rhinitis (hay fever) and allergic asthma . Allergy shots are less effective against molds and are not a useful method for treating food allergies .

Description

Allergy shorts are a series of injections with a solution containing the allergens that cause an allergic reaction. Treatment begins with a weak solution given once or twice a week. The strength of the solution gradually increases with each dose. The incremental increases of the allergen cause the child's immune system to become less sensitive to the substance by producing a "blocking" antibody. Once the strongest dose is reached, the child's sensitivity has decreased, and the injections are given monthly to control allergic symptoms.

General use

The term allergy refers to a person's immunologic sensitivity to any substance that causes an allergic reaction. Allergies can become obvious in the first few months of life in the form of nasal congestion, cough , rash, or diarrhea following food intake. Allergies affect all races and occur in all parts of the world.

Depending on the severity and nature of the allergies, allergen avoidance and allergy medications alone may not effectively manage symptoms in children. Allergens that doctors most commonly use in immunotherapy treatments for allergic rhinitis , allergic conjunctivitis , and allergic asthma include extracts of inhalant allergens from tree, grass, and weed pollens; mold spores; and dust mites. The doctor selects the treatment based on the patient's particular patterns of allergic response.

Allergy shots are not recommended for food allergies. However, if these allergies are left untreated, infants and children may be more likely to develop chronic allergies, asthma, and respiratory infections later in life. Furthermore, knowing and managing the child's sensitivities to food help in isolating the antigens that respond to immunotherapy. Parents can follow a few simple steps to reduce the child's risk to allergies:

• Pay attention to symptoms that persist, like eczema, earaches, or runny nose. See the pediatrician for treatment.
• Review the family history. If allergies run in the family, the child is likely to have them too.
• Minimize exposure to new foods in the first year. Avoid cow's milk until after the first birthday, eggs until the second birthday, and peanut butter or fish until age three. Introduce new foods in small servings.
• Eliminate from the child's diet foods suspected of being an allergy trigger and see if the symptom diminishes. Gradually reintroduce the food to see if the symptom returns. If a reaction recurs, avoid the food in the future.
• A simple blood test can help determine if the infant has allergies to certain foods and other substances. As children often outgrow allergies, they should have a second blood test to see if the allergies persist.

When to use immunotherapy

Parents considering allergy shots for their child should be referred to a board certified allergist. An allergist will follow specific steps to determine if allergy shots are necessary. The allergist will consider the child's age and general health status in deciding to start allergy treatments. The allergist will also inquire as to the child's environment (indoor and outdoor) and related symptoms to decide if testing is necessary. Allergy testing provides convincing evidence of specific antibodies to which the child is reacting. A pediatric allergist can diagnose the specific cause of the allergic reaction and provide the correct allergen extracts. He or she may also consider the following factors when deciding whether a child would benefit from allergy shots:

• The child's particular allergen may be difficult or impossible to avoid because of exposure to environment.
• Expensive medications producing side effects that adversely affect the child's health and quality of life are necessary to manage allergy symptoms. If the child's deterioration in health and the cost of allergy drugs outweigh their benefits, allergy shots may be appropriate.
• A parental commitment to see the child through the therapy is necessary for immunotherapy to work. The treatments demand a significant investment of parental time and support.

Allergy shots are also effective in treating allergic asthma. Allergy shots can help relieve the allergic reactions that trigger asthma episodes and decrease the need for asthma medications.

Skin testing

The allergist may decide to conduct skin testing on a child to determine the specific allergen that is causing a reaction in the child. In a skin test, a small dose of suspect antigens is injected under the skin. The physician looks at the injected area 20 minutes later; if it is red, with a raised area (wheal) in the center, the reaction is positive.

Skin testing should only be performed under the supervisions of a board certified allergist. The child should be followed closely during a skin test, because occasionally skin testing causes a severe reaction. This condition is unusual, since the amount of allergen used is small; however, it can happen if the child is highly sensitive to the allergen.

Preparing the shot

Once the testing is finished, the allergist prepares an allergen abstract (serum) specially for the child. If the child is sensitive to multiple allergens, the physician may mix similar abstracts in one vial. Preparing the vials in combination extracts ensures that the child receives only one shot for each group of extracts, thus reducing the number of injections needed for effective therapy.

INJECTIONS The first intramuscular injection (shot) is important because based on this experience the parent and child build an attitude toward future injections. If the child is old enough to understand, the nurse or physician will explain why the child must receive the injection. The procedure should be explained in simple terms, and should proceed quickly and as gently as possible. The child should be allowed to express his fear and resentment of needles.

Although the healthcare professional will record the allergy shot in the medical record, the parent may want to keep an updated record of the treatment for quick reference during emergencies and when the child is traveling.

INJECTION SITES The following injections sites are recommended for children:

• Infants: Outer front thigh. The parent should place the child in a secure position to prevent movement of the extremity. The parent should hold and cuddle the infant following the injection.
• Toddlers and school-age children: Buttocks, upper outer side. The buttocks do not develop until the child begins to walk, so this site is used only when the child has been walking for one year or more.
• Older children: Upper portion of the buttocks. This site provides a dense muscle mass in older children, which eliminates the possibility of injuring the nervous and vascular organs. The disadvantage of this site is that it is visible to the child who may become apprehensive when the injection is given. Older children can also receive shots in the upper arm and in the upper outer part of the thigh.

After the injection, the parent and nurse should take time to praise the child for his cooperation. Infants and small children should be cuddled and given affection for a few minutes so they do not associate the experience only with the pain . A small child may be given a toy to divert attention. Older children may be allowed to select the site for the injection. In addition, nasal sprays are in the early 2000s being developed as a painless alternative to injection delivery.

Precautions

Strict adherence is essential to an effective immunotherapy program for children. Parents should maintain as exactly as possible the injection schedule that the allergist prescribes. They should also report immediately to their healthcare provider any adverse reactions to the treatment.

Children who receive allergy shots may develop serum sickness or other problems in reaction to the treatment. Serum sickness, an allergic reaction to serum contained in the allergy shot, may occur with the first injection or as a delayed reaction. Children may have a moderate fever, local redness and itching , or pain at the site of injection and a generalized skin eruption, most commonly urticaria (hives ) associated with severe itching. The child may be uncomfortable but not seriously ill. A more severe and less common variety of serum sickness includes several of the following symptoms: malaise, protein in the urine, joint pains, swelling of mucous membranes with hoarseness and cough, vertigo, nausea , and vomiting . A rare and still more severe variety of serum illness produces extreme weakness approaching collapse; the child's temperature may be subnormal and the pulse weak. The rarest and most severe reaction, called anaphylaxis , produces immediate shock and can be fatal.

The symptoms of serum disease, particularly urticaria, may occur when a child acquires sensitivity to several drugs. Penicillin is the most frequent and important offender, and in these circumstances the symptoms are often delayed until days or even weeks after the penicillin therapy begins. Any of the symptoms of serum sickness may be mimicked. Immediate severe reactions to penicillin are almost unknown in children but can occur in adults.

There is an increased risk of a reaction with a variation of allergy shots which "rushes" the first phase of the treatment. In this treatment, steadily increasing doses of allergen extract are given every few hours instead of every few days or weeks. Rush immunotherapy should only be performed in a hospital under close supervision. Also, children who take medication that contain beta blockers for unstable heart conditions should not be given allergy shots unless the allergist thinks the benefits of starting immunotherapy outweigh the risks associated with suspending cardiac inhibitors.

Parental concerns

The goal shared by both physicians and parents in treating childhood asthma and allergies is to minimize medication side effects while maximizing the chance for children to lead normal lives. Parents can take the following steps to increase their child's comfort:

KEY TERMS

Allergen —A foreign substance that provokes an immune reaction or allergic response in some sensitive people but not in most others.

Allergic conjunctivitis —Inflammation of the membrane lining the eyelid and covering the eyeball; congestion of the conjunctiva, with mucus secretion.

Allergic reaction —An immune system reaction to a substance in the environment; symptoms include rash, inflammation, sneezing, itchy watery eyes, and runny nose.

Anaphylaxis —Also called anaphylactic shock; a severe allergic reaction characterized by airway constriction, tissue swelling, and lowered blood pressure.

Antibody —A special protein made by the body's immune system as a defense against foreign material (bacteria, viruses, etc.) that enters the body. It is uniquely designed to attack and neutralize the specific antigen that triggered the immune response.

Antigen —A substance (usually a protein) identified as foreign by the body's immune system, triggering the release of antibodies as part of the body's immune response.

Asthma —A disease in which the air passages of the lungs become inflamed and narrowed, causing wheezing, coughing, and shortness of breath.

Desensitization —A treatment for phobias which involves exposing the phobic person to the feared situation. It is often used in conjunction with relaxation techniques. Also used to describe a technique of pain reduction in which the painful area is stimulated with whatever is causing the pain.

Leukotriene antagonist —An agent or class of drugs which exerts an action opposite to that of another.

Pediatric allergist —A board certified physician specializing in the diagnosis and treatment of allergic conditions in children.

Rhinitis —Inflammation and swelling of the mucous membranes that line the nasal passages.

Urticaria —An itchy rash usually associated with an allergic reaction. Also known as hives.

• Remove carpet, launder bed linens in hot water, and keep windows closed at night and in the early morning hours to minimize exposure to outdoor allergens.
• Avoid exposure to perfume and tobacco, or other forms of smoke.
• Monitor weather and seasonal changes in an effort to minimize exposure to pollen.
• Schedule outdoor playtime or exercise at non-peak pollen periods, such as afternoons or early evening.
• Have the child wear a mask when helping in the garden or cutting the lawn, vacuuming, or dusting.
• Involve the allergist in decisions regarding child's lifestyle.

Resources

BOOKS

Berger, William E. Allergies and Asthma for Dummies. New York: John Wiley & Sons, 2000.

Lockey, Richard F., et al. Allergen Immunotherapy. New York: Marcel Dekker Inc., 2004.

PERIODICALS

Dozor, Allen J. "Kids Health and Safety: Baby Allergy Alert." Parents (September 2004): 94.

WEB SITES

"Allergy." Healthology. Available online at <www.healthology.com> (accessed December 13, 2004).

"Immunotherapy (Allergy Shots)." American College of Allergy, Asthma, and Immunology (ACAAI), March 4, 2000. Available online at <www.allergy.mcg.edu/advice/it.html> (accessed December 13, 2004).

"Immunotherapy (Allergy Shots)." Medfacts. Available online at <www.njc.org/medfacts/shots.html> (accessed December 13, 2004)

Aliene Linwood, RN, DPA