Hand involvement is common in systemic lupus erythematosus, and is different from that seen in rheumatoid arthritis. Raynaud's phenomenon was present in 50 per cent of our patients and, rather than joint deformity and synovitis, often was the primary cause of disability. Deformities in lupus hands are the result of laxity of the supporting soft-tissue structures about the joint. Articular destruction and ankylosis do not occur unless there is coexistent rheumatoid arthritis. Swanneck deformities without tight intrinsics and hyperextension deformity of the thumb interphalangeal joint are characteristic of this disease in the hand.