Drug-induced hypersensitivity syndrome associated with human herpesvirus 6 and cytomegalovirus reactivation

We describe a patient with drug-induced hypersensitivity syndrome (DIHS) associated with human herpesvirus 6 (HHV-6) and cytomegalovirus (CMV) infection induced by sulfasalazine. Two weeks after starting sulfasalazine to treat a rectal ulcer, the patient developed disseminated macular erythema accompanied by fever, liver injury, and lymphadenopathy. Seroconversion of antibodies to HHV-6 was observed. Systemic steroid treatment was not effective against the eruptions. Five months after the onset, he presented with an acute febrile disease. The detection of CMV antigen on peripheral blood leukocytes and positive staining for CMV on cutaneous endothelium indicated active CMV infection. Furthermore, he developed a bacteremia of methicillin resistant Staphylococcus aureus. An associatiation the CMV reactivation with DIHS was suggested, although there remains the possibility that the systemic steroid treatment precipitated CMV reactivation. Recently, HHV-6 has been documented to have immunomodulating effects and to be associated with CMV reactivation. Therefore, we should pay attention to the possibility of CMV reactivation in patients with DIHS in whom the immunomodulating virus of HHV-6 has been reactivated.