2023 Volume 22 Issue 2 Pages 98-103
An 81-year-old woman was diagnosed with adult-onset Still’s disease (AOSD). We started treatment with oral steroids and added methotrexate (MTX). After six weeks of treatment, during steroid tapering, she presented to our department with multiple palpable purpura on both lower extremities. Histopathological examination showed ndings of leukocytoclastic vasculitis in the supercial dermis. Immunohistochemistry showed no immunoglobulin or complement deposition and there were no ndings suggestive of collagen disease or systemic vasculitis on blood testing, and there were no signs of worsening of AOSD. We considered the possibility that she developed druginduced vasculitis caused by MTX, but continued administration because it is highly effective in AOSD. The purpura improved with rest and topical steroid application. After discharge from the hospital, she was unable to maintain rest, but only had a slight are-up of purpura. Six weeks after her rst visit to our clinic, she developed sudden fever, rapid expansion, and ulceration of the purpura on both lower legs. We suspected that the drug-induced vasculitis caused by MTX had ared up because the steroid dose was reduced. We discontinued MTX and increased the dose of oral steroids, but there was no improvement. Since the purpura at the time of relapse showed no evidence of vasculitis histopathologically and various culture tests detected Pseudomonas aeruginosa, we diagnosed as ecthyma gangrenosum. Although differentiation of ecthyma gangrenosum for other conditions, such as vasculitis, is difcult, the disease is often seen in immunosuppressed patients. Prompt diagnosis is necessary because appropriate therapeutic intervention is prognostically important. Skin Research, 22 : 98-103, 2023
