In a recent issue of the ARCHIVES, Descamps et al1 reported an association between severe drug adverse reaction, namely, drug hypersensitivity syndrome, and human herpesvirus 6 (HHV-6) infection. Although it was an interesting report, we noted 2 problems.
First, the authors cited our previous report,2 mentioning that "Human herpesvirus 6 genome was detected from peripheral blood mononuclear cells [PBMCs]" in our patient and that the value of the detection "is controversial because it can be present in healthy patients." They misunderstood our result. We isolated HHV-6 from PBMCs in 1 patient. This did not mean that we detected the viral genome in PBMCs. Human herpesvirus 6 DNA is sometimes detected in the PBMCs of healthy adults by polymerase chain reaction. However, HHV-6 is rarely isolated from the PBMCs of healthy subjects. Viral isolation from PBMCs is the most reliable method for diagnosing an active HHV-6 infection.3
Mikiko Tohyama, Koji Hashimoto. Drug Hypersensitivity Syndrome and Human Herpesvirus 6 Reactivation. Arch Dermatol. 2002;138(2):268–269. doi:10.1001/archderm.138.2.266