Drug-induced Hypersensitivity Syndrome by EGFR-TKI in a Patient with Lung Cancer.

An 83-years-old woman diagnosed with advanced Epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma was administered afatinib as a first-line treatment. On Day 17, the patient presented with grade 3 diarrhea and a blood test analysis showed an increased inflammatory response. Afatinib treatment was discontinued on the same day. On Day 26, the patient displayed blepharedema and multiple irregular erythema covering her entire body. Drug-induced hypersensitivity syndrome (DIHS) was suspected, and the systemic administration of 30 mg/day prednisolone was administered. The symptoms subsided thereafter. A blood test analysis 3 weeks after onset revealed a reactivation of Human herpesvirus 6 (HHV-6) and a diagnosis of DIHS due to afatinib therapy was confirmed.