Digital gangrene in systemic lupus erythematosus.

Digital ulcers and gangrene are common skin manifestations of connective tissue diseases, especially systemic sclerosis, although they are relatively rare in systemic lupus erythematosus. We describe here three patients with digital gangrene and systemic lupus erythematosus. None of the patients showed high disease activity of systemic lupus erythematosus at the time the digital gangrene developed. Two patients were positive for anti-RNP antibodies; however, no symptoms of other collagen diseases were present. One patient had anti-phosphatidylserine/prothrombin complex antibodies, and the other had anti-cardiolipin beta2 glycoprotein I antibodies and lupus anticoagulant at low titre. All patients showed narrowing or occlusion of radial and/or ulnar arteries in addition to digital arteries. Although a complication of anti-phospholipid syndrome is considered to be a possible cause, there may be unidentified causes other than thrombosis, atherosclerosis, overlap syndrome and vasculitis.