Riyaz, NajeebaSarita, SArunkumar, GSabeena, SManikoth, NeerajSivakumar, C P2012-09-052012-09-052012-03Riyaz Najeeba, Sarita S, Arunkumar G, Sabeena S, Manikoth Neeraj, Sivakumar C P. Drug-induced hypersensitivity syndrome with human herpesvirus-6 reactivation. Indian Journal of Dermatology, Venereology and Leprology. 2012 Mar-Apr; 78(2): 175-177.http://imsear.searo.who.int/handle/123456789/141041A 45-year-old man, on carbamazepine for the past 3 months, was referred as a case of atypical measles. On examination, he had high-grade fever, generalized itchy rash, cough, vomiting and jaundice. A provisional diagnosis of drug hypersensitivity syndrome to carbamazepine was made with a differential diagnosis of viral exanthema with systemic complications. Laboratory investigations revealed leukocytosis with eosnophilia and elevated liver enzymes. Real-time multiplex polymerase chain reaction (PCR) on throat swab and blood was suggestive of human herpesvirus-6 (HHV-6). Measles was ruled out by PCR and serology. The diagnosis of drug-induced hypersensitivity syndrome (DIHS) was confirmed, which could explain all the features manifested by the patient. HHV-6 infects almost all humans by age 2 years. It infects and replicates in CD4 T lymphocytes and establishes latency in human peripheral blood monocytes or macrophages and early bone marrow progenitors. In DIHS, allergic reaction to the causative drug stimulates T cells, which leads to reactivation of the herpesvirus genome. DIHS is treated by withdrawal of the culprit drug and administration of systemic steroids. Our patient responded well to steroids and HHV-6 was negative on repeat real-time multiplex PCR at the end of treatment.enCarbamazepinedrug-induced hypersensitivity syndromehuman herpesvirus-6Article