Ulcerative pyoderma gangrenosum

A 59-year-old woman with systemic lupus erythematosus presented with a 1-month history of an enlarging, exquisitely painful ulcer on her left calf. She reported that it had occurred secondary to a spider bite; however, the spider had not been seen. She had been assessed by a surgeon, who, suspecting an infection, débrided the wound. However, thereafter, the ulcer enlarged more rapidly. Physical examination showed a deep ulcer (8 × 7 cm), with grey, undermined borders and a necrotic base. Pyoderma gangrenosum was suspected and was ultimately confirmed after 2 biopsies were performed to rule out alternative diagnoses. Ulcerative pyoderma gangrenosum is a rare inflammatory disease with an incidence of 3...10 cases per million per year.