Human herpesvirus 6 and 7 DNA in peripheral blood leucocytes and plasma in patients with pityriasis rosea by polymerase chain reaction: a prospective case control study.

An association between pityriasis rosea and human herpesvirus 7 (HHV-7) has been reported but remains controversial. The purpose of the present study was to investigate the association between HHV-6 and HHV-7 with pityriasis rosea. Fifteen patients aged 6-54 years with a diagnosis of pityriasis rosea and 15 age-matched controls were recruited. None of the patients had HHV-6 or HHV-7 DNA detected by polymerase chain reaction in the acute or convalescent plasma specimen. In the acute peripheral blood leucocytes specimen, 3 patients and one control had RHV-6 DNA detected (p=0.299; NS), while 7 patients and 5 controls had HHV-7 DNA (p=0.355; NS). Antibody to HHV-6 was detected in the acute specimen of 13 patients and 13 controls, while antibody to HHV-7 was found in all 15 of patients and controls. We thus found no evidence of recent HHV-6 or HHV-7 infection in patients with a diagnosis of pityriasis rosea.