Toxic epidermal necrolysis due to zonisamide associated with reactivation of human herpesvirus 6.

BACKGROUND Recently, human herpesvirus 6 (HHV-6) reactivation has been frequently observed in patients with drug-induced hypersensitivity syndrome or drug rash with eosinophilia and systemic symptoms but not in patients with other types of drug eruptions, eg, Stevens-Johnson syndrome and toxic epidermal necrolysis (TEN). This finding suggests that there is a close relationship between HHV-6 reactivation and drug-induced hypersensitivity syndrome. OBSERVATIONS A 71-year-old man who was not immunocompromised developed TEN because of zonisamide therapy. After the onset of the rash, significant increases in HHV-6 IgG titers and HHV-6 DNA levels were observed in the patient's whole blood samples, indicating that an HHV-6 reactivation had occurred. Furthermore, the patient's clinical manifestations of TEN appeared to recur concurrently with HHV-6 reactivation. Conclusion Our case suggests that HHV-6 reactivation may also occur in several types of drug eruptions, including Stevens-Johnson syndrome and TEN.