Panniculitis: an unusual presenting manifestation of rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic inflammatory disease affecting primarily the joints but also other organs including skin. Panniculitis is an extremely rare manifestation of the disease manifesting mainly as reddish, ulcerative painful nodules and papules, usually in the legs. Histopathologically, it is characterised by liponecrobiosis, granulocytic and histiocytic infiltrates and vasculopathy. Herein, we describe a middle-aged woman with past medical history of hypertension and diabetes mellitus, and unremarkable family history, who presented with symmetrical polyarthritis, low grade fever and painful subcutaneous nodules in the abdomen. Her laboratory tests showed high acute phase reactants, positive rheumatoid factor and anti-Ro autoantibodies and negative anti-CCP. Surgical resection and histological examination of the nodules revealed neutrophilic lobular panniculitis associated with RA. She was treated with low doses of glucocorticosteroids and methotrexate. The latter was substituted with leflunomide due to toxicity. The patient had significant clinical and laboratory improvement.