[Studies on the novel association of human herpesvirus-7 with skin diseases].
INTRODUCTION AND AIM: Human herpesvirus 7 in pityriasis rosea, this and other viruses in papular-purpuric gloves-and-socks syndrome have been implicated, but their primary or recurrent infections are still in question. PATIENT AND METHODS: In one available blood sample, therefore, IgM, IgG and its high avidity fraction characteristic for recurrent infections were quantitated by indirect immunofluorescence. Peripheral lymphocytes were subjected to nested polymerase chain reaction to detect viral DNA, or cocultivated with several cell cultures. RESULTS: One third of 33 pityriasis rosea patients had elevated IgM, another third had elevated IgG without high avidity molecules to human herpesvirus 7 suggesting primary infection. Thirty percent of controls, more than half of the patients had virtual DNA in their lymphocytes, but only one in 5 skin biopsy specimens were PCR positive. All three co-cultivation attempts yielded viruses extremely rapidly, verified by electron microscopy, polymerase chain reaction and monoclonal antibodies as human herpesvirus 7. These are the first isolates in the geographical regions of Hungary. These data suggest that pityriasis rosea is the consequence of a primary human herpesvirus 7 infection in seronegative adults, and only occasionally is due to virus reactivation. One patient with gloves-and-socks syndrome had an acute, another patient had a persistent coinfection with human herpesvirus 7 and parvovirus B19, two others had a primary herpesvirus 7 infection. Interestingly, this disease might be elicited by both viruses individually or in synergism. CONCLUSION: Neither human herpesvirus 7 nor parvovirus B19 infect skin cells, but both can be detected in the infiltrating lymphocytes of skin eruptions, in which they induce an altered mediator production, that might be responsible for the general and local symptoms.