Necrotizing fasciitis versus pyoderma gangrenosum: securing the correct diagnosis! A case report and literature review.

OBJECTIVE: To highlight the key differences in history, examination, and management of pyoderma gangrenosum and necrotizing fasciitis and to outline the importance of distinguishing these 2 conditions.

METHOD: We present a case report of a gentleman with a background of ulcerative colitis having a 1-week history of an erythematous wound and localized abscess to the right leg that failed to respond to antibiotic treatment and later on to surgical debridement of a presumed necrotizing fasciitis. Following referral to our plastic surgery unit, a diagnosis of pyoderma gangrenosum was made and this was confirmed following a response to steroid therapy within 48 hours. A literature review of pyoderma gangrenosum cases misdiagnosed for necrotizing fasciitis was carried out to compare and contrast pitfalls in misdiagnosing these 2 conditions.

RESULTS: Literature review of 10 cases confirmed the association of pyoderma gangrenosum with inflammatory bowel disease, hematological disease, and surgical trauma. The presence of necrotic tissue in a pyoderma gangrenosum lesion can be a diagnostic pitfall; although blood and tissue culture investigations are usually negative in pyoderma gangrenosum, this may not always be the case. Inflammatory markers can be significantly high in pyoderma gangrenosum and pyrexia is not a feature limited to necrotizing fasciitis.

CONCLUSIONS: Inappropriate surgical debridement of pyoderma gangrenosum can cause rapid extension of the lesion by enhancing the posttraumatic response and lead to potential reconstructive challenges with psychological repercussions. On the contrary, treating necrotizing fasciitis with immunosuppressive therapy may worsen the condition. The importance of understanding the pathogenesis, clinical features, and management of both conditions cannot be overemphasized.