title: Drug-induced hypersensitivity syndrome with human herpesvirus-6 reactivation.
abstract: A 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.
authors.affiliation: Department of Dermatology and Venereology, Government Medical College, Calicut, India. najeeba_riyaz@rediffmail.com
authors.forename: Najeeba
authors.initials: N
authors.lastname: Riyaz
authors.forename: S
authors.initials: S
authors.lastname: Sarita
authors.forename: G
authors.initials: G
authors.lastname: Arunkumar
authors.forename: S
authors.initials: S
authors.lastname: Sabeena
authors.forename: Neeraj
authors.initials: N
authors.lastname: Manikoth
authors.forename: C P
authors.initials: CP
authors.lastname: Sivakumar
mesh_terms: D000927:Anticonvulsants / Q000009:adverse effects; D002220:Carbamazepine / Q000009:adverse effects*; D003875:Drug Eruptions / Q000209:etiology* / Q000821:virology*; D015654:Herpesvirus 6, Human; D006801:Humans; D008297:Male; D008875:Middle Aged; D019349:Roseolovirus Infections / Q000821:virology*; D014775:Virus Activation / Q000187:drug effects*
chemical_list: D000927:Anticonvulsants; D002220:Carbamazepine