Human betaherpesvirus 7 (HHV-7) is one of nine known members of the Herpesviridae family that infects humans.
Both HHV-6B and HHV-7, as well as other viruses, can cause a skin condition in infants known as exanthema subitum, although HHV-7 causes the disease less frequently than HHV-6B. HHV-7 infection also leads to or is associated with a number of other symptoms, including acute febrile respiratory disease, fever, rash, vomiting, diarrhea, low lymphocyte counts, and febrile seizures, though most often no symptoms present at all.
There are indications that HHV-7 can contribute to the development of drug-induced hypersensitivity syndrome, encephalopathy, hemiconvulsion-hemiplegia-epilepsy syndrome, hepatitis infection, postinfectious myeloradiculoneuropathy, pityriasis rosea, and the reactivation of HHV-4, leading to mononucleosis-like illness.
Complications with HHV-7 infection has been shown to be a factor in a great variety of transplant types.