Treatment of severe cutaneous small-vessel vasculitis with mycophenolate mofetil.

A 46-year-old man presented with a 5-week history of painful purpuric ulcerative lesions on his legs (Figure1). A skin biopsy specimen taken by his referring physician exhibited perivascular infiltration of polymorphonuclear leukocytes, fibrinoid deposition on the vessel walls, and extravasation of erythrocytes that was diagnostic of small-vessel vasculitis (leukocytoclastic vasculitis). No involvement of the deep dermis or subcutaneous tissue was noted in the pathology report. A prior 10-day course of prednisone had proven ineffective. His medical history was positive for intermittent hematuria that predated his vasculitis by several years. The hematuria was microscopic and had been worked up by a urologist and determined to be without systemic involvement. There were no other positive findings on review of systems and no evidence of systemic vasculitis. Medications at the onset of his vasculitis included sertraline, ibuprofen, and zolpidem, none of which was new. Laboratory evaluation revealed no abnormalities in his complete blood cell count, comprehensive metabolic panel, hepatitis profile, erythrocyte sedimentation rate, or serum protein electrophoresis. Serologic findings were negative for cryoglobulins; ANCA; and anti-Smith, antiScl-70, anti-Ro (SS-A), anti-La (SS-B), antihistone, anti– Jo-1, and anticentromeric antibodies. Urinalysis findings were positive for 2 blood, 2 protein, and 11 to 30 red blood cells per high-powered field, consistent with the microscopic hematuria in the patient’s history. Findings of direct immunofluorescence studies of a biopsy specimen taken from the presumed newest lesion on the left thigh were scantly positive for IgM in blood vessels and negative for IgA and IgG; C3 findings were moderately positive in a few vessels and in a discontinuous granular pattern along the basement membrane. Treatment was initiated with colchicine, 0.6 mg twice daily, along with dapsone, 150 mg/d. This regimen blocked the development of new lesions, but there was no change in the ulcerations with these therapies. During the course of his treatment, the patient developed abdominal pain, which he attributed to dapsone, and therapy was discontinued.