Why is pyoderma gangrenosum a dermatologic emergency?

Pyoderma gangrenosum is one of a group of inflammatory skin diseases called neutrophilic dermatoses because, histologically, they have dermal infiltrates of neutrophils. It is a dermatologic emergency because it is often rapidly progressive, causing severe local tissue destruction. Pyoderma gangrenosum is frequently misdiagnosed as an infectious process or a brown recluse spider bite and is then treated by debridement. However, surgical procedures or any mechanical manipulation of acute lesions induces progression of disease to the normal surrounding skin, enlargement of the lesion, and further tissue destruction. Therefore, it is imperative to recognize and treat these lesions correctly early to avoid massive tissue destruction and loss.