JEADV ISSN 1468-3083 JEADV 2006, 20, 667– 671 © 2006 European Academy of Dermatology and Venereology 667 Blackwell Publishing Ltd ORIGINAL ARTICLE The detection of human herpesvirus-8 DNA in plasma and peripheral blood mononuclear cells in adult patients with pityriasis rosea by polymerase chain reaction AAT Chuh,*† PKS Chan,‡ A Lee† † Department of Community and Family Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, China ‡ Department of Microbiology and School of Public Health, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, China Keywords exanthem, herald patch, human herpesvirus-6, human herpesvirus-7, human herpesvirus-8 *Corresponding author, The Bonham Surgery, Shop B5, Ning Yeung Terrace, 78 Bonham Road, Ground Floor, Hong Kong, tel. +852-25590420, 852-25174081; fax +852-23703330; E-mail: achuh@iohk.com Received: 4 January 2005, accepted 15 April 2005 DOI: 10.1111/j.1468-3083.2006.01569.x Abstract Background Herpesvirus-like particles have been reported to be detectable by electron microscopy in lesional biopsy of patients with pityriasis rosea (PR). We report a study investigating the association of PR with human herpesvirus-8 (HHV-8) infection. Methods Our setting is a teaching clinic affiliated to a university. We recruited eight patients aged 28 – 47 years (mean: 34.5 years) diagnosed with PR during a one-year period. We collected acute blood specimens at presentation and convalescent blood specimens three to four weeks later. We also collected skin scrapings from the herald patch where present and from truncal secondary lesions. Results We detected HHV-8 DNA by a nested PCR (polymerase chain reaction) targeting, respectively, a 233-bp and a 160-bp fragment of ORF 26. PCR for HHV-8 DNA was negative in the peripheral blood mononuclear cells and plasma of acute and convalescent specimens of all patients, and negative in all skin scrapings. We detected anti-HHV-8 IgG and IgM antibodies by the indirect immunofluorescence. Four patients had IgG antibodies against HHV-8, but with no significant rise of titre. None were positive for anti-HHV-8 IgM antibody. Conclusion We conclude that PR is not associated with HHV-8 infection. Background The aetiology of pityriasis rosea (PR) is unknown. Recent controversy is centred on the novel herpesviruses, particularly human herpesvirus (HHV)-7. Investigators have reported positive 1–7 as well as negative 8–17 results. Drago et al. 4 have reported the detection of herpesvirus- like particles by electron microscopy in lesional biopsy specimens of their patients with PR. These together with their previous detection of HHV-7 from the peripheral blood mononuclear cells, skin, and plasma of PR patients during their acute disease, suggest a role for HHV-7 in this condition. 4 Nevertheless, with the ubiquitous nature of herpesviruses and their similarity in morphology, further virological evidence to prove the aetiological association is desirable. Because members of the herpesvirus family are mor- phologically undistinguishable under electron micros- copy, the viruses observed by Drago et al. 4 could be HHV-6, HHV-7 or indeed any other herpesvirus. Lesions in PR are orientated along lines of skin cleavage. 18 There is one other disease in which lesions follow lines of skin cleavage: Kaposi’s sarcoma. 19 Apart from Kaposi’s sarcoma, HHV-8 is also aetiologically associated with primary effusion lymphoma, multicentric Castleman’s disease, multicentric Castleman’s disease- related immunoblastic and plasmablastic lymphoma, and various atypical lymphoproliferative disorders. The