Periungual lesions in pyoderma gangrenosum.

Pyoderma gangrenosum (PG) is a progressive cutaneous necrosis of unknown origin. We report a case of PG presenting with periungual lesions. A 57-year-old woman was on treatment with ciclosporin A for PG. During tapering of the ciclosporin A dose, proliferating periungual lesions developed on the third and fourth finger of the left hand, the fourth finger of the right hand, and on the right great toe and the left fifth toe. All lesions appeared within a 4-week period. These abnormalities were ulcerated, involved about one-third of the distal part of the lateral nail folds including the part of nail fold bordering on the free edge of the nails, and were very painful. The skin biopsy was consistent with that seen in PG. Increasing the ciclosporin A dose led to significant improvement in the periungual lesions within the next few weeks and complete resolution within 6 months.