ABSTRACT
Mast cell (MC) disorders are related to increased MC infiltration, overactivation, or both. Vasoactive mediators including tryptase and histamine and cytokines and chemokines are released from activated MCs, resulting in clinical manifestations. Mastocytosis involves an abnormal clonal expansion and accumulation of MCs in tissues such as the bone marrow and/or skin. MC disorders are classified as primary (systemic mastocytosis/subtypes, cutaneous mastocytosis/subtypes, and monoclonal MC activation syndrome), secondary, and idiopathic MC activation syndromes. Patients with systemic mastocytosis can have symptoms due to multisystem involvement including the skin, respiratory, gastrointestinal, cardiovascular, musculoskeletal, and neuropsychiatric symptoms, as well as anaphylaxis. Cutaneous mastocytosis involves the skin but may present with abdominal cramps and anaphylaxis. MC activation triggers include stress, heat, alcohol, exercise, insect sting, infection, and medications. Investigations include serum tryptase, peripheral blood KIT [D816V] mutation, and bone marrow evaluation depending on the case. Diagnosis of systemic and cutaneous mastocytosis are based on diagnostic criteria. Management in general includes trigger avoidance, epinephrine auto-injector, and a MedicAlert bracelet. In cutaneous mastocytosis, management options include antihistamines, topical/systemic corticosteroids, and phototherapy. Management options for systemic forms include antihistamines, leukotriene receptor antagonists, MC stabilizers, combination therapy, biologics, chemotherapy, and bone marrow transplant.
