Mastocytosis and Hymenoptera allergy

Purpose of review Mastocytosis is a rare disease with associations with anaphylactic reactions to Hymenoptera stings. The purpose of this review is to examine these associations with regard to prevalence, diagnosis, treatment and prognosis in the insect-venom-allergic population. Recent findings Systemic mastocytosis is overrepresented in the Hymenoptera-allergic population and is associated with an increased risk of more-severe reactions following field stings or sting challenges, lack of sensitization to venoms by skin test or radioallergosorbent test, increased side effects to venom immunotherapy, reduced efficacy of venom immunotherapy and treatment failures. Serum tryptase determinations are a simple and reliable screening procedure for systemic mastocytosis. Patients with elevated values should be referred to specialized centers for confirmatory diagnosis including bone marrow histology. Summary The diagnosis of systemic mastocytosis should be considered in Hymenoptera-allergic patients showing any of the management problems associated with this disease. Patients with mastocytosis and Hymenoptera allergy require special attention, mainly because of reduced safety and efficacy of venom immunotherapy. Whether or not venom immunotherapy is given, such patients should continue to carry an Epipen (R) indefinitely.