Acute monocytic arthritis

Five patients with the triad of fever, skin rash, and acute polyarthritis were studied with regard to synovial fluid analysis. All cases revealed inflammatory effusions with a predominant monocytosis. Skin biopsies from two cases and synovial membrane biopsy from one case revealed a nonnecrotizing vasculitis. Although the etiology of this syndrome was not ascertained, it bears striking similarities to certain viral arthritides. It also deserves consideration as a form of acute hypersensitivity angiitis.