Allergy shots, desensitization, hyposensitization, injections, or immunotherapy - whatever term you use, is the treatment of allergic disorders by injecting small doses of allergen to the allergic patient. The procedure usually takes many weeks or months and begins with a small amount of a highly diluted allergen which is injected in the upper arm, just under the skin. Each week, increasing amounts of allergen are injected first by increasing the dose, followed by an increase in concentration until the patient reaches a "top" dose-either the strongest dose we offer or the highest amount tolerated by the patient.
Once the patient reaches this "top" dose we call this the maintenance dose and we continue weekly injections at this level. Hopefully the patient is experiencing relief of symptoms and possibly is decreasing the use of their medication. Depending upon the time and how the patient is doing we try to stretch out the interval between shots to every 2, 3 and eventually every 4 weeks. Reactions to the shots may cause us to slow down the program and even go backwards. We are trying to achieve a maximum dose with no side effects and excellent control of the symptoms.
The allergy shots may be missed due to illness or vacation. Depending on the individual situation adjustment in dose and schedule will be made. If you have a significant fever or flu or if you are actually wheezing the "shot" needs to be cancelled and rescheduled for a week later.
Frequently a question arises as to how long will this program last. There is no standard answer to that question. It is an individual decision. For the most part, the longer the program is continued the longer the benefit from the therapy. As a general rule you should expect to stay on the program for 3-5 years. If a patient is on every 4 weeks, and is not taking anything for the allergy other than the shots, and this situation has been present for at least a year, there should be a strong consideration of stopping the shots. Some allergists will use 3 successive seasons of relief. Again, this is an individual decision. There is no way other than by history to know when to stop the allergy shot program. Skin test results may decrease during treatment, but are not usually used as a discontinuation criterion.
There is also no way to know how long a patient will do well after the program is stopped. Some may have life-long relief, others may have a relapse. With relapses, another course should be started.
If after one year of treatment and the patient is at a "top" maintenance dose and there is no change in the symptoms - we need to consider:
- Lack of environmental control
- Chronic infection
- Another allergy has developed
Often times there may be a new sensitivity that develops in some patients. At this point a re-evaluation is necessary. If nothing can be found then a discussion about stopping the program should occur. Please give the program at least one year before deciding if it has worked for you (or your child).