Frequently Asked Questions
Q. WHAT DISEASES OR CONDITIONS ARE TREATED WITH ALLERGY SHOTS?
A. “Allergy Shots” (the medical term is allergen immunotherapy) are used to treat some cases of respiratory allergic diseases. This means those allergic diseases affecting the nose, lining membranes of the eye, and bronchial tubes.
The medical name for allergy affecting the nose is allergic rhinitis; allergens in the air affecting the membranes lining the eyeball is termed allergic conjunctivitis; allergic reactions to airborne substances which occur in the bronchial tubes in the lungs may cause inflammation and spasm of the lining of the bronchial tubes, which is known as asthma. Allergy shots are also used to prevent future reactions in persons who have had serious allergic reactions to venoms of stinging insects.
Q. DOES EVERY PERSON WHO HAS PERSISTENT NASAL PROBLEMS OR ASTHMA NEED ALLERGY SHOTS?
A. NO. Many cases of persistent nasal symptoms or asthma are not caused by allergy to airborne substances and will not respond to treatment with allergy injections. Many cases which are indeed caused by allergy can be satisfactorily treated by allergen avoidance or medication, without need for allergy injections. Whether allergen injection treatment is indicated is determined by evaluation of the individual patient’s case by an allergy and clinical immunology specialist.
Q.WHAT DO ALLERGY SHOTS CONSIST OF?
A. Allergy shots consist of the unavoidable ariborne allergens to which the particular patient has been found sensitive in a purified and sterilized form.
Q. HOW DOES INJECTING THE ALLERGENS INTO A PATIENT HELP IN CONTROLLING THE ALLERGIC DISEASE?
A. Injecting these substances stimulates the body’s protective mechanisms to produce immunity to the allergens, which partially counteracts the effects of the allergic antibodies in the patient’s body which promote allergic reactions on exposure to the allergens. The process of acquiring partial immunity to allergen exposure has some similarity to that involved in vaccination with viruses and bacteria, such as polio and tetanus.
Q. DOES IT MATTER HOW MUCH ALLERGEN IS GIVEN IN THE INJECTIONS?
A. Yes. It is absolutely crucial that an adequate dosage of each allergen be given in order for treatment with allergy shots to be effective. If the dosage used is too low, the immune system will not be adequately stimulated to produce protective antibody.
Q. WHY DO ALLERGENS NEED TO BE GIVEN BY INJECTION?
A. It is not possible with materials currently routinely available in the United States for an effective amount of allergens to be absorbed into the body by any other route.
Q. HOW SOON DO ALLERGY SHOTS TAKE EFFECT?
A. Usually it takes several months for allergy shots to produce a noticeable effect. The reason that it takes so long is that the initial dosage must be very low, too low to stimulate the immune response. In the first few months of injection treatment, each dose is greater than the one before.
Protection against the effects of allergen exposure occurs only after the higher dosages are reached. If the dosage were to be started too high or increased too rapidly, unpleasant reactions may occur.
The principle behind allergy immunizations is that immunity is build-up in a stepwise manner, so that the protective response produced by the first injection permits a higher dose to be given on the second injection, and so forth, until the full dose is finally reached. Usually the final, protective dosage is 1000 to 10,000 times higher than the starting dosage.
Often patients continue to have gradual improvement in their allergy symptoms over the first two years of injection treatment. In general, whatever degree of improvement that can be expected from allergen immunotherapy will have occurred by three years after initiation of therapy.
Q. SINCE IT TAKES SEVERAL MONTHS FOR ALLERGY SHOTS TO BEGIN TO WORK, DOES THE PATIENT SIMPLY HAVE TO SUFFER IN THE MEANTIME?
A. No. Sixty years ago this was true, but now there are many effective medications (pills and sprays) available for treatment of inhalant allergy. Most of these take effect within hours to days. When allergy shots do begin to take effect, the amount of pill or spray medication needed to control the condition is decreased. Because of the long interval between beginning allergen injection therapy and the onset of benefit, allergy shots are used as an adjunct to treatment with oral medication and nasal sprays or bronchial inhalers, which take effect much more rapidly.
Q. WILL ALLERGY SHOTS COMPLETELY CURE NASAL ALLERY OR ASTHMA?
A. No. Symptoms of inhalant allergy are lessened and requirement of allergy medications is greatly decreased in most cases, but the vast majority of patients continue to have some allergy symptoms and need some oral or spray medications despite receiving allergy injections. Complete remission of allergy symptoms occurs only in a very small number of patients.
Q. WHAT ARE THE SIDE EFFECTS OF ALLERGY SHOTS?
A. The most common side effect of allergy injections is mild soreness, redness, swelling, local heat and tenderness at the site of the injections. Typically this is greatest 2 or 3 hours after the injection and is gone by the next morning. If such local reaction lasts over 24 hours, the dosage should be held steady and not increased until the excessive degree of local reaction is no longer occurring.
Nearly all patients receiving allergy injections have some local reaction – it is a sign that the body is making immunity, the local reactions usually become less of a problem, and the dosage can continue to be increased. A potentially much more serious effect of allergy injections is a systemic reaction. Only a small minority of patients have this type of reaction.
Q. CAN SYSTEMIC REACTIONS BE DANGEROUS?
A. Yes. Signs and symptoms of systemic reactions include breaking out in welts all over the body, sneezing or coughing attack, wheezing, flushing, racing heart, weakness, fall in blood pressure, fainting and swelling of the face, tongue, and throat. Typically such reactions begin within one-half hour of the injection, but occasionally they may not occur until 2 hours after the injection. In extremely rare cases, systemic reactions to allergy injections can be fatal, due to interference with breathing and fall in blood pressure.
Q. WHAT IS DONE TO TREAT A SYSTEMIC REACTION IF IT OCCURS?
A. Systemic reactions are treated with an injection of epinephrine (adrenaline) under the skin, which usually acts promptly to stop the reaction. Severe reactions may require more intensive treatment in addition to the epinephrine.
Q. IS THERE ANYWAY OF COMPLETELY PREVENTING SYSTEMIC REACTIONS?
A. No. The administration of effective dosages of allergy extracts entails a small but unavoidable risk of systemic reaction. The incidence and severity of systemic reactions is diminished, however, by meticulous attention to detail in all aspects of the treatment.
Q. IF A SYSTEMIC REACTION OCCURS, SHOULD ALLERGY INJECTIONS BE STOPPED?
A. No. In general, patients who have systemic reactions have large amounts of allergic antibody in their body, and stand to benefit the most from allergy injection treatment. If a systemic reaction occurs, the dosage needs to be temporarily reduced and then built up slowly again.
Q. HOW OFTEN ARE ALLERGY INJECTIONS GIVEN?
A. Since benefit from allergy injections requires that a relatively large dosage be attained, injections are given frequently at the beginning of treatment, usually once or twice weekly. Once the maintenance dosage (full dosage) is reached, the injections are spread out to every two weeks, and eventually to once a month.
Q. WHY MUST ALLERGY INJECTIONS BE GIVEN REGULARLY?
A. Injections must be given regularly for reasons of safety and effectiveness. Systemic reactions are more frequent when injections are given erratically; the escalations in dosage required to build effective immunity cannot be made if an excessive period of time has elapsed between injections.
Q. SHOULD PATIENTS HAVE ALLERGY INJECTIONS MORE FREQUENTLY WHEN THEY ARE HAVING MORE SYMPTOMS?
A. No. While this was a popular practice several years ago, more recent research has clarified that allergy injections act as a prophylactic treatment – if taken regularly prior to exposure to allergens, patients have less intense symptoms when they are exposed to the allergens. There are now a variety of effective medications for treatment of allergy symptoms when they occur.
Q. HOW LONG DOES A PATIENT CONTINUE TO TAKE ALLERGY INJECTIONS?
A. Several years of treatment are required to attain lasting improvement, which persists long-term after injections are stopped, in the patient’s allergic condition. The duration of treatment is determined for each patient on an individualized basis. If injections are given for less than three years, relapse is expected.
Q. SHOULD PATIENTS GIVE THEIR OWN INJECTIONS?
A. Allergy injections should be NEVER be self-administered by the patient. The primary reason for admonition is that in the event of a systemic reaction, the patient may rapidly become too ill to self-administer epinephrine rapidly and take other necessary emergency measures.
Injections are best administered in clinics where physicians and nursing staff are very familiar and experienced with allergen treatment. Epinephrine must be immediately available when allergy injections are given.