Snapshot quiz 15/7

Published: 07/06/2015

Authors: Rance C and Jones A

Pyoderma gangrenosum (PG). PG is an uncommon inflammatory and ulcerative skin condition that typically affects young and middle-aged adults, with a female preponderance. It presents with an inflammatory pustule which rapidly progresses to a painful skin ulcer that has a characteristic violacious border. More than half of patients who develop PG have associated systemic disease, notably inflammatory bowel disease. However, unlike erythema nodosum, which is more commonly seen in inflammatory bowel disease than PG, ulcer severity is less likely to be linked directly to disease activity.

Diagnosis is based on history and clinical examination. Biopsy typically shows dermal neutrophilia, accompanied by a mixed inflammatory cell infiltrate with or without lymphocytic vasculitis. Treatment is of the underlying systemic disease. PG lesions usually regress rapidly following treatment with systemic corticosteroids.