A study of synovial fluid and cytology in arthritis associated with herpes zoster

A case of herpes zoster complicated by acute arthritis with effusions is described. The white cell count in the synovial fluid was low, with a predominance of neutrophils. The synovium showed superficial deposits of fibrin, slight intimal hyperplasia, and subintimal polymorph infiltration. Varicella virus was not detected by culture or electron microscopy, but varicella antigen was demonstrated in the cytoplasm of macrophages in the effusion. Other findings did not determine whether the antigen had appeared in the joint from circulating immune complexes, or following synovial phagocytosis or proliferation of virus.