Cutaneous Manifestations of Mastocytosis

Doctor Karen Hartman, a professor of medicine and head of the Division of Allergy at the University Hospital in Basel, Switzerland, presented on the cutaneous manifestations of mastocytosis. Mastocytosis involves an expansion of mast cells in tissues, especially skin, often seen in three categories: cutaneous mastocytosis, systemic mastocytosis (which may be indolent or advanced), and very rarely, mast cell sarcoma. The most common form is indolent systemic mastocytosis, usually associated with skin involvement and distinct lesions. Key features include the Darier sign, where lesions swell upon scratching. Cutaneous mastocytosis presents in children as mastocytoma or urticaria pigmentosa, while adults typically have a monomorphic variant. The prognosis for childhood forms is generally good, often resolving by adolescence, whereas adult cases tend to persist. Diagnostic approaches include assessing skin lesions, measuring serum tryptase levels, and identifying the KIT DH16V mutation. Advanced systemic mastocytosis may warrant further tests like bone marrow biopsies. Treatment options include managing symptoms, epinephrine auto-injectors for anaphylaxis, and emerging tyrosine kinase inhibitors like evaicritinib, showing some promise for improving skin lesions. Hartman emphasized the importance of collaborative care among dermatologists and researchers to enhance patient outcomes.