Central nervous system demyelination associated with tofacitinib use in alopecia areata: A case report and literature review

We describe a 23-year-old woman with alopecia areata (AA) who developed new central nervous system (CNS) demyelination while on tofacitinib therapy. After 3 months of tofacitinib 10 mg/day and topical tofacitinib, the patient had dramatic scalp hair regrowth (severity of alopecia tool score improved), but in the 4 th month, she developed focal neurological symptoms. Brain magnetic resonance imaging showed multiple new T2-hyperintense lesions in the right pontine tegmentum, showing mild diffusion restriction and subtle contrast enhancement and patchy non-enhancing T2/FLAIR hyperintensities in the juxtacortical region of the right parietal lobe, deep white matter region of the right occipital and left frontoparietal lobes, and in the callosal septal interface. These features represent demyelination and cerebrospinal fluid (CSF) studies showed very high protein with negative CSF myelin oligodendrocyte glycoprotein/neuromyelitis optica antibodies and absence of oligoclonal bands. Tofacitinib was discontinued and the patient received high-dose corticosteroids. We review the literature on Janus kinase inhibitor-associated demyelination, including prior case reports, hypothesized mechanisms, risk factors, and regulatory guidance. Current evidence indicates a temporal association between tofacitinib exposure and CNS demyelination, although causality remains uncertain. The demyelinating episodes appear reversible upon drug withdrawal with immunotherapy. This case underscores the need for vigilance for neurological symptoms in patients on tofacitinib and further research into its neuroimmunologic effects.