Peristomal pyoderma gangrenosum is best described as which of the following?

• A. A bacterial infection of the skin
• B. A benign skin lesion
• C. Mechanical dermatitis from friction
• D. An ulcerative autoimmune disease, with unknown etiology

Answer: (D)

Peristomal pyoderma gangrenosum is a sterile, inflammatory skin condition around a stoma driven by an abnormal immune response (a neutrophilic dermatosis). It is not an infection, so antibiotics won’t reliably help and cultures are often negative. The lesions are painful ulcers that can expand rapidly and may have undermined, violaceous borders, sometimes following minor trauma to the skin (pathergy). It is commonly associated with inflammatory bowel disease or other autoimmune conditions, and the exact cause is unknown. Treatment centers on systemic immunosuppression (such as steroids or other agents) and gentle wound care, while avoiding aggressive debridement, which can worsen the lesion. This description—an ulcerative autoimmune inflammatory process of the peristomal skin with unknown etiology—best fits.