What is Immunotherapy? (also known as allergy shots)
Immunotherapy (allergy shots) is a treatment used to alleviate allergic symptoms of hay fever or asthma by administering injections of substances called allergens, such as pollens, mold spores, dust mites, animal dander, or insects to which an individual has been found to be allergic by skin testing. Although the precise mechanism of its effect is the subject of current research, immunotherapy “turns down” the allergic reactions to environmental allergens.
Immunotherapy gradually decreases your sensitivity, but improvement is usually not noticed initially, however, continuation of injections leads to further improvement. Sensitivities to allergens are diminished with immunotherapy, resulting in less severe symptoms and the need for fewer medications. While it is uncommon to achieve a complete cure, the vast majority of people derive a very significant benefit from immunotherapy. If no benefit is noted after 12 months of treatment, it may be decided to discontinue immunotherapy.
How are injections given and for how long?
Allergy injections are initially administered weekly in increasing dosages during the “build up” phase, which typically takes 5-7 months (in some instances this process can be sped up by receiving injections twice weekly or with accelerated schedules). Once you have reached your “maintenance” dose, the frequency of injections will be gradually spread out to every 2 weeks, then every 3 weeks, and finally monthly injections. It is very important not to miss any appointments because this will cause a setback in reaching or continuing the maintenance dose. After achieving good results for 3-5 years, you have the option of discontinuing allergy injections. Most patients will continue to do well, others may require additional medication, and some patients will require restarting allergy injections (indefinitely) to control their symptoms.
Immediate and delayed local reactions such as swelling itching or redness at the site of the injection are common. These mild reactions typically subside in less than a day.
Large local reactions and generalized (systemic) reactions occur in 1-5% of patients receiving immunotherapy. These reactions can occur at any time: however they are more common during the “build up” phase. Most generalized reactions are mild and may consist of any or all of the following symptoms: swelling and redness at the injection site, itchy eyes, nose, or throat, nasal congestion or runny nose, tightness in the throat or chest, coughing, or wheezing, and hives or generalized itching. In a very small fraction of the cases, more sever generalized reactions occur which can lead to shock, or in extreme circumstances, even death.
Allergy injections must be administered in a medical facility where a physician is present so that reactions may be promptly treated. Additionally, since virtually all serious systemic reaction will develop within 30 minutes, we require that you wait 30 minutes after every injection for observation. This is for your safety. Since certain medications can increase your risk from a reaction, you should notify the medical staff of any prescription and nonprescription medications you are taking. We should also be notified if you become pregnant or if there is a possibility that you are pregnant.
Modified from AAAAI Web site www.aaaai.org