Venom allergen immunotherapy.

Venom immunotherapy (VIT) with Hymenoptera venom extracts is highly effective in preventing large local, systemic allergic, and anaphylactic reactions to insect stings. VIT is not required for patients with cutaneous systemic or large local allergic reactions to stings because it is uncommon for reactions to become more severe. The clinical history, with confirmatory skin or serum tests for venom IgE, can clarify the risk for future anaphylaxis and the need for VIT. For initial treatment, rush regimens are recommended because they have the same or less risk of systemic reactions than slower traditional regimens. VIT is relatively safe with a low incidence of systemic reactions. Injection-site reactions can be bothersome but do not predict systemic reactions to venom injections. Patients who need VIT should be screened for baseline serum tryptase and possible underlying mast cell disorders. VIT can be discontinued after five years in most patients, but those with known high-risk factors should continue VIT indefinitely.