Case Report: A Novel KRT74 Variant in an Eight-Year-Old Boy with Alopecia Totalis Successfully Treated with Baricitinib

This case report describes the successful treatment of an 8-year-old boy with alopecia totalis, associated with a novel KRT74 gene variant, using the JAK inhibitor baricitinib. The patient experienced significant hair regrowth within 1 month of treatment, with continued improvement over 8 months. Genetic analysis identified a heterozygous KRT74 variant, also found in his mother and brother, who did not have alopecia. The study suggests that KRT74 variants may affect immune responses in the scalp, contributing to alopecia areata, and highlights the potential of baricitinib in treating genetically driven inflammatory conditions. It also proposes further research into KRT74 as a biomarker for alopecia areata susceptibility.