Acalabrutinib is a second-generation, highly selective Bruton's Tyrosine Kinase inhibitor (BTKi) indicated for use in some mature B-cell malignancies. The authors describe a uniquely distributed drug reaction presenting as palpable purpura over the bilateral upper limbs. BTKi is theorised to cause haemorrhage through off-target inhibition of Tec kinases and EGFR receptors. Dermatologists play an integral role in the multidisciplinary management of these patients to limit the negative impact on patient quality of life and, more importantly, to restrict dose reduction or treatment discontinuation.
Keywords: Acalabrutinib; Bruton’s tyrosine kinase inhibitor; EGFR inhibitor; Purpuric drug eruption; Small vessel vasculitis.
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