Henoch-Schönlein purpura after etanercept therapy for psoriasis.
Etanercept is a recombinant dimeric fusion protein consisting of a tumor necrosis factor-alpha receptor ligand-binding region linked to the Fc portion of human IgG. It is approved for use in the treatment of rheumatoid arthritis, ankylosing spondylitis, juvenile rheumatoid arthritis, psoriasis, and psoriatic arthritis. Since 1998, there have been reports of vasculitic adverse events, including necrotizing vasculitis and leukocytoclastic vasculitis. In addition, the adverse events reporting system of the U.S. Food and Drug Administration has recorded 35 cases of leukocytoclastic vasculitis, 20 after etanercept therapy and 15 after infliximab. Most cases of cutaneous vasculitis describe development of symptoms within 3 months of etanercept use. In only one case report was direct immunofluorescence performed on tissue and no specific immunoreactivity found. We describe the first case of Henoch-Schönlein purpura with acute renal failure associated with increase in etanercept dose after 11 months of use for treatment of psoriasis. Discontinuation of the drug and treatment with a course of systemic steroids led to the complete resolution of the vasculitis and improvement of renal function. Vasculitis occurring even during chronic use of antitumor necrosis factor agents must be considered as possibly related to the therapy.