[Infections with herpesvirus 6--really only "exanthema subitum"? Part 2: Rare or unknown disease pictures].

The human herpes virus 6 (HHV 6) may induce not only the wellknown condition of exanthem subitum, but also a number of more common (cf. Part 1) or rare, even previously unknown, clinical manifestations. Part 2 of this paper deals with the more rarely observed manifestations. These include complications of ARD (sinusitis, otitis media, bronchial pneumonia) hepatitis, encephalitis or Pfeiffer's disease (mononucleosis-like syndrome). In individuals with a relevant disposition (genetic HLA/DR type?) initiation or (re-)activation of rheumatoid arthritis (JCA = juvenile chronic arthritis) or chronic iridocyclitis may occur. Although, on account of the high prevalence of vaccination in our population (approximately 95%), prenatal infections are extremely rare, they may manifest in a severe "septic" form (fatalities have occurred) or may lead to neurological deficits (comparable with cytomegalovirus infection). To date, no specific therapy (e.g. gammaglobulin, virostatics) or reliable preventive measures (e.g. vaccination) are available.