Dr. Lorelei Natasha Bourla, MD

Before treatment is begun, patients and their doctors first have to identify different factors that trigger their symptoms. Then, skin tests are done to confirm which substances cause allergic reactions. Blood tests may be performed as well, but they are typically not necessary.

There are two phases to subcutaneous allergen immunotherapy: a build-up phase and a maintenance phase. The build-up phase lasts three to six months, during which patients receive shots with increasing amounts of the allergens once or twice a week. When the effective dose is reached, the maintenance phase begins and may continue for up to five years.

Although allergy shots are the longest-lasting and most effective allergy treatment available, they are not for everyone. If patients have heart problems, high blood pressure, or severe asthma, they should not be given allergy shots. The injections are generally safe, but they may have a little swelling at the injection site, which is normal. Rarely, severe shock-like reactions, called anaphylaxis, can also occur. Patients will likely be required by their doctor to stay for half an hour after their shot, so in the event of an anaphylactic reaction, it can be treated immediately.