Case historyA 63 year old woman presented with painful, stiV hands. There was swelling of the hands, ankles and feet but no systemic upset. On examination there was soft tissue thickening of the proximal interphalangeal (PIP) and metacarpal phalangeal (MCP) joints of the hands with pitting oedema of the hands, feet and lower legs. The remainder of the examination was unremarkable. The following investigations were negative or normal. Full blood count and diVerential, erythrocyte sedimentation rate (ESR), C reactive protein (CRP), rheumatoid factor, nuclear antibody profile, thyroid function. Serological investigation for parvovirus B19 was negative. Radiographs of the hands revealed soft tissue swelling but no erosions.During the following six months the patient developed synovitis of PIP joints and wrists (fig1) with bilateral dorsal sheath eVusions ( fig 2). Multiple firm nodules were noted on both elbows and forearms measuring up to 1 cm (fig 2) and she developed symptoms and signs of carpal tunnel syndrome.The patient now fulfilled ARA 1987 diagnostic criteria for rheumatoid arthritis 1 with early morning stiVness, swelling of PIP joints for greater than six weeks, symmetrical joint swelling, and rheumatoid nodules. There were, however, atypical features; the ESR was normal, the rheumatoid factor was negative, and there was marked peripheral oedema. Further investigations were performed. Immunoglobulins, vasculitis profile and C3,C4, C3d were normal. Brucella, hepatitis A and B, and Borrelia serology was negative. Chest radiograph and isotype bone scan were normal. Histological examination of the nodules revealed a mixed inflammatory cell infiltrate consisting of lymphocytes, mononuclear cells, and histiocytes. There was some destruction of blood vessels and collagen fibres. Central fibrinoid necrosis with macrophage palisading, characteristic of a rheumatoid nodule, were not identified. Biopsy of peripheral oedematous skin revealed superficial and deep panniculitis with perivascular inflammation composed of lymphocytes and histiocytes. Abdominal ultrasound and computed tomography of thorax, abdomen, and pelvis were negative. A presumptive diagnosis of rheumatoid arthritis with atypical features was made and a trial of treatment was started with 7.5 mg of prednisolone and 250 mg of d-penicillamine daily. The synovitis, oedema, and panniculitis improved but the nodules persisted. Over the next two years, at close review, the patient remained stable with treatment.