Pyoderma gangrenosum, acne conglobata, and lgA gammopathy

A 62‐year‐old man was evaluated for chronic recurrent pyoderma gangrenosum (PG) of 8 years’ duration. He had a long history of acne conglobata beginning in his early twenties. Although periods of inactivity lasted for months, renewed cyst formation recurred on the face, trunk, and groin. Minocycline, 100 mg twice daily, was useful for the control of acne. Severe periodontal disease developed 25 years prior to presentation. He had coronary bypass surgery 12 years ago. His family history was noncontributory and negative for PG, acne conglobata, or follicular occlusion (FO) triad. The patient presented with an 8‐year history of small hemorrhagic pustules on the legs, progressing over the subsequent few months to large ulcers with raised borders. Spikes in temperature and general malaise for 3 or 4 days sometimes heralded new PG eruptions. On examination, large inflammatory, scarring cysts were present, predominantly on the face, lateral neck, back, and inguinal areas. Both lower legs showed small hemorrhagic pustules and scattered ulcers with raised, irregular borders ( Figs 1–3). The larger ulcers often began as painful nodules, with central necrosis; peripheral expansion led to the formation of a central mucopurulent base surrounded by an undermined, ragged, erythematous or dusky, edematous ulcer rim. A vague, serpiginous halo of erythema surrounded these lesions. 1Multiple necrotic ulcerations of pyoderma gangrenosum on the leg, demonstrating raised, inflammatory borders, a mucopurulent base, and a surrounding halo of erythema. Cribriform scarring is also apparent2Characteristic ulcer of pyoderma gangrenosum consists of a boggy, necrotic base with ragged, undetermined, violaceous edges surrounded by a halo of erythema3Close up of leg ulcer in Fig. 2A biopsy specimen taken from the erythematous border of a leg ulcer showed a massive neutrophilic infiltrate with necrotizing suppurative inflammation and limited necrotizing vasculitis; direct immunofluorescence examination gave nonspecific results. Thrombosis of the small vessels, edema, and extravasation of erythrocytes were also noted. These histologic findings support the clinical diagnosis of PG. Serum protein electrophoresis revealed a monoclonal, immunoglobulin A (lgA) kappa‐type gammopathy. Bone marrow evaluation showed a slight elevation of plasma cells, suggesting a benign monoclonal gammopathy; urine analysis did not demonstrate Bence‐Jones protein. Evaluation for gastrointestinal, liver, and hematologic disease was negative. A complete blood cell count and blood chemistries gave results within normal limits. Oral prednisone, 60 mg daily, dapsone, 200 mg daily, and trimethoprim/sulfamethoxazole DS, twice daily, were administered. Prednisone was reduced to 30 mg every other day when the large ulcers of the legs ceased to expand, and regression was noted. Cribriform scarring was seen in areas of healing. Systemic prednisone eventually produced noticeable side‐effects, including bilateral cataract formation and the development of tachycardia. Isotretinoin was begun with excellent initial results, but the patient had to discontinue therapy due to frontal headaches, scleral hemorrhage, the development of painful heel pads, and elevated hepatic function tests. The patient remained on minocycline, 100 mg twice daily, with relatively good control of the acne. Pustules were treated adequately with topical corticosteroids; larger ulcers were well controlled with intralesional corticosteroids and short courses of oral prednisone. Colchicine, 0.6 mg twice daily, and dapsone, 100 mg twice daily, were continued at maintenance levels for several years, and topical clobetasol propionate was applied to new lesions as they appeared.