Pyoderma gangrenosum: an unusual cause of periaural ulceration.

A case of pyoderma gangrenosum affecting the pinna and neck of a diabetic patient is reported. Appearances were suggestive of malignant otitis externa. A small biopsy resulted in rapid and aggressive exacerbation of the lesion. Pyoderma gangrenosum, although uncommon, should be considered as a cause of ulceration, particularly when the ulcer yields no growth on culture in a non-dependent area.