Seronegative polyarthritis as severe systemic disease.

BACKGROUND Severe extra-articular disease is associated with high levels of rheumatoid factor (RF ) in patients with seropositive rheumatoid arthritis (RA ) and a poor prognosis. It is said that patients with seronegative rheumatoid arthritis have a more benign course and less destructive disease. We observed several patients with seronegative non-rheumatoid polyarthritis, with aggressive extra-articular systemic disease. OBJECTIVES Review of seronegative systemic polyarthritis with clinical presentation of typical cases. METHODS Medline search for systemic manifestations of seronegative polyarthritis. CLINICAL PRESENTATIONS 1. A 56-year-old woman was admitted to the cardiac intensive care unit with stabbing presternal chest pain aggravated by breathing and progressive dyspnoea, which gradually developed over a period of two weeks with one episode of fever at 38.0 degrees C. She had suffered chronic pain in her buttocks for three years with polyarthralgia and evanescent palmar-plantar rash. Imaging showed bilateral sacroiliitis (HLA B27 negative) and a large pericardial effusion. Extra-articular manifestations of SAPHO syndrome were proposed and she was successfully treated with combined therapy: pulse methylprednisolone, azathioprine, colchicine and prednisone. 2. A 47-year-old woman with psoriatic arthropathy developed high fever with leucocytosis and thrombocytosis and lung infiltrates during exacerbation of her joint disease . She was treated with pulse methylprednisolone followed by corticosteroid tapering, anti-TNF (infliximab) and methotrexate with complete resolution. 3. A 19-year-old man with inflammatory bowel disease developed acute pericarditis with response to 6-mercaptopurine, salazopyrine and prednisone. RESULTS We discuss a range of seronegative arthritis diseases with possible systemic manifestations including the main procedures for early diagnosis. Infection, malignancy, hypersensitivity, granulomatous disease and other collagen diseases such as systemic lupus erythematosus should be excluded, but investigations for an underlying disease should not delay early corticosteroid and immunosuppressive therapy. CONCLUSION A high level of suspicion of extra-articular disease should always be maintained when treating active seronegative polyarthritis.