Insect Allergy

Abstract

Between 0.5–3.3% of adults and 0.15–0.8% of children in the US will experience a systemic reaction to a Hymenoptera sting, with higher risk in individuals likely to be exposed to these insects. Allergy to Hymenoptera venoms is an immunoglobulin E (IgE) mediated reaction to venom components of bees, vespids (hornets, wasps, and yellow jackets), or imported fire ants (IFA). Insects other than Hymenoptera may cause IgE-mediated reactions too. Cross-linking of venom-protein specific IgE bound to high-affinity receptors on mast cells and basophils releases a variety of mediators such as vasoactive factors, cytokines, and chemo-attractants. These mediators result in local and systemic allergic signs and symptoms. Correct diagnosis of insect allergy relies on a detailed history as well as identification of specific IgE, usually with skin tests, at least 2–4 weeks following the insect sting. Validated testing for specific-IgE identifies insect allergy in subjects with a history of a systemic reaction following a sting. Increased baseline serum tryptase detects individuals at greater risk. Avoidance of circumstances with higher probability of stings and appropriate use of IM epinephrine is one strategy for addressing insect sting allergy. Allergen immunotherapy, using venom for wasps, yellow jackets, honey bees and hornets and whole body extracts for imported fire ant, reduces the risk of systemic allergic reactions to a level similar to the general population. After 3–5 years of allergen immunotherapy, the treatment can be discontinued, usually with life-long protection.