What is Immunotherapy?

Immunotherapy or Allergen Immunotherapy aka Allergy shot is a way to desensitizing your body to exposure to substances that cause an allergic reaction in your body.

How does it work?

Immunotherapy involves identifying allergens that disturb your immune system. Once these allergens are identified a diluted solution is made up of these allergens with one part of allergens and 5000 parts of diluent. This vaccine is administered subcutaneously and given over a period of time with gradually increasing doses. With this the body develops a tolerance or immunity towards the allergen and there would be minimal or no symptoms of allergy over the exposure to the allergen.

What are the benefits of Immunotherapy?

Physicians usually prescribe antihistamines to treat allergies. Antihistamines merely block the action of histamine relieving allergic symptoms, they cannot prevent allergic reactions from taking place. On the contrary, Immunotherapy actually trains our immune system to become tolerant to allergic reactions. The gradual exposure to the offensive allergen in increasing amount desensitizes the immune system.

Limitations of Immunotherapy

Immunotherapy is a boon for patients who are susceptible to anaphylaxis due to stinging of insects like wasps and bees but it has not been proven effective in case of food allergies. This may be so because of the different antibody mechanism involved in food allergies.

Side effects of Immunotherapy

Immunotherapy may lead to a large localized reaction to the allergy injection at the site of injection, usually the upper arm of the patient. This leads to redness, swelling and itchiness at the site of reaction. There is also a risk of a systemic reaction like hives or anaphylaxis. But this risk can be avoided if the patient rests well before undertaking Immunotherapy.

How safe is Immunotherapy?

Immunotherapy or allergy shots are generally safe and seen working for both children and adults. They are also reported to be safe for pregnant women although some doctors prefer avoiding them during pregnancy. Immunotherapy is not recommended in case of older patients also. It is surprising that research suggests immunotherapy is very effective when started at a young age since it prevents future sensitization in children.