A 67‐year‐old man presented in April 1983 with three painful ulcers with bluish margins on the right shin and the lower back. The largest lesion was 6 cm in diameter. The lesions had started as painful nodules 8 months previously; these ulcerated within 2 weeks and fluctuated in size. There was no history of arthritis or bowel disease. Full blood count, erythrocyte sedimentation rate, serum electrolytes, urea, and liver enzymes were normal. Antinuclear antibody and rheumatoid factor were negative. The serum IgA level was elevated at 7.35 g/L (normal 0.8–4 g/L). Immunoelec‐trophoresis revealed IgA kappa paraproteinemia. Bence Jones protein was not found in the urine. Skeletal survey, bone marrow, sigmoidoscopy, and rectal biopsy were normal. No bacterial pathogens were grown. Histology of the edge of the ulcer showed dermal abscesses, dermal granulation tissue, and chronic inflammatory infiltrate extending to the subcutis.
During the next 2 years the patient developed active pyodermatous lesions on the trunk and left arm. Between April 1983 and March 1986, the patient received a combination of prednisolone 15–40 mgand azathioprine 50–100 mg daily, a 12‐week course of dapsone 200 mg daily, and repeated courses of oral and topical antibiotics. During this period, although the disease activity was lessened, the lesions never healed completely.
In April 1986, the pyoderma gangrenosum was more active; the ulcers enlarged and deyeloped active pustules at the margins. While the patient was still taking prednisolone 15 mg and azathioprine 50 mg, oral cyclosporin A 6 mg/kg daily (250 mg twice daily) was started; after 3 weeks, the dosage was increased to 10 mg/kg daily (400 mg twice daily) and the prednisolone was reduced to 5 mg daily over 2 months. At 3 weeks the ulcers started to heal, and at seven weeks all ulcers healed, leaving papery scars. Over a period of 4 weeks, the dosage of cyclosporin A was gradually reduced and the ulcers remained healed at a maintenance dosage of 250 mg daily. There was no change in the paraproteinemia. Weekly whole blood cyclosporin A levels were measured, and they fluctuated between 800 ng/ml and 910 ng/ml. On two occasions the levels were >1500 ng/ml.
During the course of the treatment, the patient developed nausea, hypertrichosis, transient thrombocytopenia, and hypertension (blood pressure of 190/110 mmHg); creatinine clearance fell from 87 to 46 ml/min. At a maintenance dosage of 250 mg daily, the blood pressure was 180/100 mmHg and creatinine clearance was 64 ml/min.
