Rare Case of Pyoderma Gangrenosum in the Setting of PAPA Syndrome in a 12-Year-Old Child

Abstract

We report on a 12-year-old boy who presented with an intermittently painful wound present for months without any tendency to heal after a slackline accident two years ago. A biopsy of the ulcer margin revealed epithelial hyperplasia, marked fibrosis, and vascular proliferation without evidence of vasculitis. Pretibial findings on the right side were a 3.8 ×  3.1 cm fibrin-covered, flat ulcer with slight reddening of the surrounding area. Other findings were unremarkable with hypermobility of the wrists and finger joints. Local therapy with a foam dressing, topical steroid in the wound margin, and class II compression stockings showed no effect. The pediatric rheumatologist evaluated the ulcer with a camptodactyly of digit 5, subluxation of the wrists on both sides, and symmetric ulnar deviation. Elevated S100 as an isolated autoimmune phenomenon or concomitant with systemic autoimmune disease or autoinflammation (eg, Pyogenic sterile arthritis, pyoderma gangrenosum, and acne syndrome) was also observed. The therapy with oral steroids, initially 30 mg/day and gradual reduction in the course, only achieved a tissue bridge's formation with the same size extension of the ulcer. Unfortunately, the patient spontaneously developed a second ulcer on the left lateral malleolus, which is why the therapy was changed to dapsone 50 mg/day and tacrolimus in the wound margin after nine weeks. In the absence of success, further treatment with ciclosporin or tumor necrosis factor-alpha antibody therapy is planned in interdisciplinary cooperation.