Allergy immunotherapy is a form of treatment to prevent allergic reactions by building up the immune system’s resistance. This is done through controlled exposure to substances that the person may be allergic to.
“[It] slows the progression of allergies, reduces symptoms, and hopefully eliminates the allergy,” says Dr. Bassett. “In children, it may prevent or slow down the progression from allergies to asthma.”
Immunotherapy can be administered as allergy shots, drops, or biologic medications.
Allergy shots involve injecting small amounts of allergen extracts into the body to stimulate the immune system without causing an allergic reaction. Your doctor may increase the allergen dose over time to help desensitize you to environmental allergies.
The shots work like a vaccine, as your body develops immunity and tolerance to particular allergens after being exposed to them.
Allergy drops are also known as sublingual immunotherapy (SLIT). In this form of immunotherapy, a small dose of an allergen is delivered in liquid or tablet form under the tongue to boost tolerance and immunity and reduce allergy symptoms.
Several SLIT tablets are available by prescription, including ones that contain dust mites (Odactra), extracts from pollens of different types of grass (Grastek), or weeds such as ragweed (Ragwitek).
Biologic medications are another form of immunotherapy used for an ever-expanding list of allergic diseases such as asthma, eczema, sinus disease (nasal polyps), and hives. Most are given as injections to target a specific reaction in the immune system and try to prevent it from occurring. Some of the most commonly used biologic medications on the market now include dupilumab (Dupixent) to treat allergic skin reactions and omalizumab (Xolair) to treat asthma or hives.