We thank Drs Tohyama and Hashimoto for their comments on our article. We recently reported in 4 of 7 consecutive patients with drug hypersensitvity syndrome the presence of anti–HHV-6 IgM antibodies with a seroconversion of anti–HHV-6 IgG in 2 of them.1 Serum samples were collated at the day on admission and 2 weeks later, independent of the onset of the disease. We agree with the suggestion that in the 3 patients in whom it was not possible to demonstrate a rise in HHV-6 IgG titers the samples were perhaps collected too early or too late. In our first reported case of association between HHV-6 infection and drug hypersensitivity syndrome, the rise in anti–HHV-6 IgG was also observed late: HHV-6 IgG antibody titers were 80, 160, and greater than 320 in samples collected on days 20, 28 and 35, respectively, after the onset of the disease.2 We were also aware of the limits of this study, but we assumed that when a serum sample was collected before the rise in antibodies, HHV-6 DNA could be detected by polymerase chain reaction as viremia may be present before emergence of antibodies.3 HHV-6 DNA was not detected in these sera. On the other hand, we do not think that all cases of drug hypersensitivity syndrome are associated with HHV-6 infection.
Descamps V, Mahé E. Drug Hypersensitivity Syndrome and Human Herpesvirus 6 Reactivation—Reply. Arch Dermatol. 2002;138(2):269. doi:10.1001/archderm.138.2.266