Detection of Herpes simplex Virus Genomic DNA in Various Subsets of Erythema multiforme by Polymerase Chain Reaction

Abstract

Background: The wide variation in the detection of herpes simplex virus (HSV) DNA (36–75%) by polymerase chain reaction (PCR) in erythema multiforme (EM) may be partly attributed to differences in case selection in terms of subsets of EM studied. Objective: To determine the frequencies of detection of HSV DNA in specific subsets of EM. Methods: Nested PCR was used to detect HSV DNA in skin biopsies with histologically proven EM. Results: PCR was performed on skin biopsies from 63 patients with EM. HSV DNA was detected in 3/11 (27.2%) of single-episode HSV-associated EM (HAEM), 6/10 (60%) of recurrent HAEM, 1/4 (25%) of single-episode idiopathic EM and 6/12 (50%) of recurrent idiopathic EM. HSV DNA was not detected in atypical EM (0/11), suspected drug-induced EM (0/9) or Stevens-Johnson syndrome (0/6). Conclusion: The overall PCR positive rates of HAEM (42.9%) and idiopathic EM (43.8%) were comparable suggesting that idiopathic EM is likely to be related to a subclinical HSV infection.