Allergy shots, also known as allergen immunotherapy, are a long-term treatment that decreases symptoms for patients with seasonal allergies (hay fever), perennial allergic rhinoconjunctivitis (an allergy to dust mites, mold spores, pet dander, cockroach), allergic asthma, eczema, and stinging insect allergy. Allergy shots result in “desensitization” to allergens. Patients can then have increased exposure to their allergic triggers without developing troublesome symptoms.