[An adult patient with varicella preceded by acute thrombocytopenia].

A 40-year-old man was admitted to our hospital because of a tendency to bleed. A diagnosis of idiopathic thrombocytopenic purpura was made, and oral prednisolone (1 mg/kg/day) was administered immediately. Three days after admission, hemorrhagic skin rashes highly suggestive of varicella appeared. The oral prednisolone was discontinued, and intravenous gamma-globulin (400 mg/kg/day for 3 days) and aciclovir (750 mg/day for 7 days) were started. The platelet count increased to 254,000/microliter over the next five days, and the skin rashes associated with varicella subsided within a week. We suggest that, in a minority of patients with varicella zoster infection, thrombocytopenia can precede the typical skin rashes, so a search for possible underlying viral infection should be made, and if necessary, immediate treatment started.