Venom immunotherapy. Side effects and efficacy of treatment

Venom immunotherapy (VIT) protects patients with Hymenoptera venom anaphylaxis from subsequent potentially life-threatening reactions. The most important side effect are systemic anaphylactic reactions (SAR). Compared to the administration of aqueous extracts according to a rush protocol, the frequency of systemic and also local side effects will be lower if depot extracts are used and a slow conventional dose schedule is used, as compared to rush desensitization with aqueous extracts. However, protection often has to be achieved rapidly, and adequate surveillance of sufficient duration is hardly feasible in outpatients. Therefore, VIT according to rush schedules in inpatients remains indispensable. Pre-treatment with H 1 -blocking antihistamines reduces frequency and intensity of local and mild systemic adverse reactions during VIT. Up to 25% of patients again develop a SAR when re-stung while on VIT with the usual maintenance dose of 100 μg venom. Patients with honeybee venom allergy or with mastocytosis are at a higher risk for treatment failure. Almost all of them will become fully protected by increasing the maintenance dose, 200 μg venom being sufficient in most cases. Patients with significant risk factors may be treated from the beginning with an elevated maintenance dose, particularly when they are allergic to honeybee venom.