Mast cell diseases in patients with insect venom allergy: implications for diagnosis and therapy

Abstract

Clonal mast cell disease is detected in up to 5% of adult patients with insect venom allergy. Mastocytosis and monoclonal mast cell activation syndrome (MMAS) are considered high-risk diseases in Hymenoptera venom allergy (HVA). Literature review. Mastocytosis or MMAS are detected in HVA patients more frequently than random chance would permit. Patient histories in mast cell disease often reveal particularly severe sting reactions. Moreover, the risk of side effects is higher and the likelihood that specific immunotherapy (SIT) using Hymenoptera venom (HV) will fail is greater. The determination of baseline serum tryptase (bST) and an examination of the skin are recommended in all adult patients with a previous history of systemic sting reactions. Patients with mastocytosis of the skin and/or bST elevated above 20 µg/l should always undergo further investigation. If bST is elevated in the absence of mastocytosis, or if a more accurate diagnosis of the mast cell disease is relevant, a so-called liquid biopsy can be performed, enabling a KIT mutation (tyrosine kinase receptor) to be investigated in peripheral blood. Bone marrow biopsy, bone density measurement, and upper abdominal ultrasound are also indicated. Due to the specific hazards posed by clonal mast cell diseases, HV-SIT is of particular relevance to this patient group. Patients with clonal mast cell disease are at greater risk of treatment failure and should therefore undergo sting challenge. In bee venom allergy, one should try to achieve a higher maintenance dose (200 µg bee venom) from the start, likewise in patients with wasp venom allergy and sting reactions requiring resuscitation. Lifelong continuation of HV-SIT is recommended in mast cell disease.