Malignant pyoderma: A clinical variant of pyoderma gangrenosum

A 43-year-old woman was admitted to our clinic with ulcers on her scalp, face, and neck for 2 months that were gradually spreading to the trunk and the upper and lower extremities. Clinical examination and vital signs were completely normal. On dermatologic examination, there were multiple round-to-oval ulcers, 2 to 4 cm in diameter, with necrotic bases. At the same locations, there were also erythematous papulopustular lesions. On laboratory examination, the erythrocyte sedimentation rate was 30 mm per hour and the white blood cell count was 23,000 per mm3. Hemoglobin, hematocrit, urinalysis, blood chemistry, throat, blood, and wound cultures from the wound, stool analysis, VDRL, RPR, TPHA, antistreptolysin-O titer, C-reactive protein, rheumatoid factor, IgG, IgA, IgM, C3, C4, anti-ds-DNA, Th/Ts ratio, c-ANCA, posteroanterior lung roentgenogram, abdominal ultrasonogram, and a computerized tomogram of the brain were within normal limits. Pathologic examination of sections of skin biopsies stained with hematoxylin and eosin taken from four different morphologic lesions (papule, pustule, ulcer, and ulcer edge) revealed dense neutrophilic infiltration throughout the dermis, abscess formation, and necrosis. There was neutrophilic abscess formation within hair follicles suggesting a suppurative folliculitis. Secondary vasculitic changes such as thrombi within vessels and fibrin deposition around the vessel walls immediately beneath the ulcer were also observed. Pseudoacantholytic changes due to dense neutrophilic infiltration within the epidermis and follicular epithelium were also observed. At the periphery of the ulcer, there were no prominent vascular changes indicating a true vasculitis. Specialized stains failed to reveal any infectious organisms. These findings are thought to be consistent with pyoderma gangrenosum. Systemic clinical and laboratory investigations showed neither inflammatory bowel disease nor any other systemic disorder. The patient had been on 100 mg fluocortone therapy for 1 month and the dose was decreased to 60 mg the day before she was admitted. Clofazimine 300 mg was added to the therapy because of inadequate response to corticosteroids. Antiseptic baths with potassium permanganate solution and silver sulphadiazine-containing creams were applied topically. Although the initial clinical response seemed to be good, new lesions appeared within 4 weeks. At this point clofazimine was replaced by dapsone, 200 mg per day; fluocortone was reduced gradually and then discontinued. A dramatic clinical response was observed within 2 weeks. The ulcers had healed with scar formation and there were no new lesions. Dapsone was successfully reduced to 100 mg per day as methemoglobin levels tended to rise. By the end of the second month there was no relapse with good drug tolerance.