LAUSR

CAE: cutaneous adverse events GIST: gastrointestinal stromal tumor KIT: tyrosine-protein kinase KIT/CD117 LCV: leukocytoclastic vasculitis PDGFRA: platelet-derived growth factor receptor alpha TK: tyrosine kinase TKI: tyrosine kinase inhibitor INTRODUCTION Tyrosine kinase (TK) inhibitors (TKI) are a widely used and important class of oncologic agents with diverse and well-described cutaneous adverse events (CAE). Avapritinib is a newly approved selective TKI with activity against tyrosine-protein kinase KIT/CD117 (KIT) and platelet-derived growth factor receptors (PDGFR)used in the treatment of gastrointestinal stromal tumors (GIST) harboring specific exon 18 mutations. Here we present a case of an avapritinib-induced palpable purpuric eruption clinically mimicking cutaneous leukocytoclastic vasculitis (LCV).