Antiphospholipid-antibody-associated panniculitis

A 60-year-old man presented with intermittent, tender, erythematous nodules on the legs that were associated with mild arthralgias. He was otherwise asymptomatic but reported a history of lupus anticoagulant antibodies that were discovered incidentally on laboratory screening at the approximate time that his lesions first occurred. A biopsy specimen showed a septal and lobular panniculitis with neutrophils, histiocytes, numerous eosinophils, foci of fibrosis, and fat necrosis but no vascular pathology. An elevated activated partial thromboplastin time (PTT), appreciably elevated levels of anti-beta-2 glycoprotein I antibody (IgM and IgG), and moderately elevated levels of anticardiolipin antibody (IgM and IgG) were present. The onset and recurrence of his skin condition coincided with increased antiphospholipid antibody levels and treatment with 81 mg aspirin daily was associated with improvement.