Vegetative pyoderma gangrenosum: An unusual presentation

A 44-year-old woman presented with a 6-month history of subcutaneous nodules involving her face and shins. Her past history revealed myomatous uterus with menometrorrhagia, resulting in an iron deficiency anemia, treated by ferrum sulfate tablets. She also had diabetes mellitus type II treated by glibenclamide and metformin tablets. There was no evidence of bromide or iodide ingestion. On initial examination, several firm, tender, erythematous subcutaneous nodules, 2-4 cm in diameter, were present on the face (Fig. 1) and shins (Fig. 2), two with normal overlying skin. Within a few weeks, the nodule on the left shin enlarged and several superficial ulcers appeared, surrounded by purplish borders, secreting sinuses, and a vegetative exophytic surface (Fig. 3). Physical examination was normal. Incisional biopsies from the ulcer margins showed pseudoepitheliomatous hyperplasia, diffuse neutrophilic infiltration with microabscess formation (Fig. 4), and the presence of a dense infiltrate composed of epithelioid cells, giant cells, and a few lymphocytes forming non-necrotizing granulomas within the dermis and subcutaneous lobules (Fig. 5). Leukocytoclastic vasculitis was also present in the lower dermis. Routine blood tests and urine analysis were normal, except for a high erythrocyte sedimentation rate (120/h) and anemia with a hemoglobin level of 10 g%. The results of the following laboratory tests were found to be within normal limits: rheumatoid factor; antinuclear antibody; C3; C4; serum immunoglobulins; serum protein electrophoresis; stool for parasites and occult blood; X-ray of the chest, left shin, hands, and facial bones; isotopic bone scanning; abdominal ultrasonography; chest and abdominal computerized tomography. Repeated smears and tissue cultures for bacteria, mycobacteria, and fungi obtained from several ulcer sites were negative. Smears and cultures for Leishmania and polymerase chain reaction (PCR) for Leishmania were negative. Based on the clinical and histologic picture, our case was diagnosed as vegetative pyoderma gangrenosum. The lesions did not respond to systemic antibacterial agents including minocycline and cotrimoxazole. A marked improvement was observed following treatment with prednisone at an initial dose of 40 mg/day. Relapse of the lesions was observed after several attempts to reduce the steroid dose. Using dapsone as an adjuvant therapy in increasing dose up to 250 mg/day induced significant improvement, which allowed us to reduce the dose of prednisone to 10 mg/day. Dapsone was discontinued after 3 weeks of treatment due to acute hepatitis induced by the drug. A few days after cessation of dapsone, the cutaneous lesions recurred, and were only partially controlled by a prednisone regimen of 10/20 mg on alternate days. Complete remission was achieved after 6 months of therapy, leaving a small cribriform scar on the leg.