Pyoderma gangrenosum in association with erythema elevatum diutinum: report of two cases.

We report on the appearance of centrifugally spreading ulcers with undermined borders in two patients with chronic recurrent erythema elevatum diutinum controlled with dapsone. The ulcerated lesions were consistent on clinical and pathologic examination with the diagnosis of pyoderma gangrenosum. They eventually responded to treatment with oral corticosteroids. The addition of cyclosporine was required in one case. No associated disease was found in any of the patients. The possible pathophysiological mechanisms of this uncommon association are reviewed.