Pyoderma gangrenosum. A possible cause of wound necrosis.

Pyoderma gangrenosum is a destructive cutaneous disorder characterized by painful, rapidly enlarging ulcers with under-mined bluish and purplish red margins. This disease is most frequently found in association with ulcerative colitis. However, in the last three years, four cases of pyoderma gangrenosum precipitated by surgical procedures have occurred, and only one of these patients had ulcerative colitis. All four patients responded to steroid therapy and local wound care. Pyoderma gangrenosum can first be suspected by recognition of the previously described classic lesion. In addition, the absence of significant microbial growth and the lack of a specific etiology ascertained on routine and special staining of biopsy material is suggestive of the diagnosis. Histologic characteristics are entirely nonspecific but can be helpful in ruling out other specific entities. The progressively destructive nature of this process in the face of what would seem to be appropriate therapy for bacterial wound infection requires that pyoderma gangrenosum, as well as other aspects of the differential diagnosis of a persistent ulcerative lesion, such as fungal infection, factitious ulcer, or vasculitis, be considered.