Infantile-onset arthritis and multisystem inflammatory disease: "a new syndrome".

A case is presented with early-onset polyarthritis involving both large and small joints, prolonged fever, skin rash, hepatosplenomegaly, persistent cerebro-spinal fluid pleocytosis, brain atrophy, macrocephaly with ventricular dilatation, a persistently open fontanelle, lymphadenopathy, subcutaneous nodules, developmental delay, failure to thrive, persistent hypochromic microcytic anemia, leukocytosis with shift to the left, early thrombocytopenia followed by thrombocytosis, high erythrocyte sedimentation rate, elevated immunoglobulin level, and vasculitis involving several organs. Thirteen cases have been previously reported under different names. A unified name is needed; we suggest "infantile-onset arthritis and multisystem inflammatory disease."