Systemic vasculitis complicating hairy cell leukaemia treatment with cladribine

Summary A single course of cladribine has been used commonly over the past decade to treat hairy cell leukaemia, with an impressive rate of complete remission and few serious adverse effects. Although vasculitis has been reported in the course of hairy cell leukaemia, it has only rarely been reported as the consequence of cladribine treatment. We describe a 73‐year‐old woman who developed serious systemic vasculitis with associated thrombocytopenia in the course of treatment with cladribine.