Detection of viral DNA within skin of healed recurrent herpes simplex infection and erythema multiforme lesions.

The polymerase chain reaction (PCR) was used to detect HSV DNA in genomic DNA extracted from skin biopsies obtained from healed skin of five patients with hyperpigmented macules following recurrent cutaneous HSV infections and from eight patients with HSV-associated erythema multiforme (EM). A 92-bp HSV-1 DNA fragment was found in all the skin biopsies from the site of recurrent HSV infection and in five of eight (62%) biopsies from the EM patients. Virus DNA was not found in tissues distant from the site of HSV recurrence or from a patient without a history of HSV infection. These findings confirm the presence of HSV in healed skin from the site of recurrent HSV disease and are consistent with the concept that HSV is involved in EM pathogenesis.