Drug-induced hypersensitivity syndrome and HHV-6 reactivation

Drug-induced hypersensitivity syndrome (DIHS) is an adverse reaction with clinical signs of fever, rash, and internal organ involvement. The culprit drugs of DIHS are limited to several drugs such as carbamazepine, phenytoin, phenobarbital, zonisamide, allopurinol, salazosulfapyridine, diaphenylsulphone, and mexiletine. The association of HHV-6 reactivation with DIHS has been known. Flaring of symptoms such as fever and hepatitis is closely related to HHV-6 reactivation. A combination of immunologic reaction to a drug and HHV-6 reactivation results in the severe course of DIHS.