Chronic destructive elbow arthropathy associated with hydroxyapatite crystals in a patient with systemic lupus erythematosus.

We describe the case of a young woman with systemic lupus erythematosus (SLE) who presented with painful acute swelling and limited motion of the elbow. Analysis of synovial fluid exhibited a noninflammatory cell count, negative cultures, amorphous nonbirefringent particles, and a positive Alizarin red S staining. X-rays showed calcifications, spurring, sclerosis, and despite the short duration of symptoms, loss of radial-humeral and cubital-humeral joint spaces. The diagnosis of an acute attack within a chronic degenerative arthropathy of the elbow associated with hydroxyapatite crystals was established. Such crystal-induced arthropathy can be an occasional explanation for acute arthritis in SLE.