[The blood picture in exanthema subitum (Zahorsky)/ critical 3-day fever-exanthema in young children].

Exanthema subitum was described in 1910 by John Zahorsky/USA; in 1986 and 1988 the human herpesvirus 6 (HHV 6) was discovered as the causative agent of the disease and serologic tests were established for diagnostics (specific IgM and IgG antibodies). Up to this time the diagnosis was based on the typical clinical course: the prodromal febrile stage (3 days) followed by the onset of a (more or less characteristic) rash closely connected with the normalisation of the body temperature. Usually a typical white blood cell count was described for diagnostics on the first day of exanthema: leukocytopenia with eosino- and granulocytopenia associated with consequent lymphocytosis. We analysed the hematologic data for children with a serologically documented HHV6 infection including exanthema (group 1: n = 9), without exanthema (group 2: n = 11) or with a serologically unexplained febrile rash (group 3: n = 13). In children with exanthematous HHV6 infection (exanthema subitum) granulocytopenia and a decreased thrombocyte count (mean values) is the rule. But the total white blood cell count and the mean values for eosinophils did not differ between the groups studied.