Systemic administration of Janus kinase inhibitors (JAKis) is associated with adverse events, including serious infections, malignancy, and herpes zoster (HZ). Herein, we report a case of a 17-year-old male with alopecia universalis who developed suspected HZ-associated encephalitis (HZAE) during treatment with oral tofacitinib. Oral tofacitinib was immediately discontinued, and the patient was started on antiviral treatment. We present this case to highlight a serious complication that can arise with oral JAKi therapy. Physicians should have a high index of clinical suspicion for HZAE in any patient presenting with a vesicular rash and concomitant neurologic impairments while systemically immunosuppressed.
Keywords: Encephalitis; Janus kinase inhibitor; herpes zoster; tofacitinib.