Abstract
Canities subita is a rare condition characterized by sudden hair pigmentation loss. Although its etiology is under discussion, an association with alopecia areata (AA) has been proposed. We present the case of a 60-year-old male with rheumatoid arthritis who experienced abrupt hair whitening and a large bald occipital patch. Diagnosed with canities subita with concomitant AA, treatment with baricitinib led to remarkable hair repigmentation within 8 months and repopulation of the occipital patch. This case supports the link between canities subita and AA, evidenced by similar presentations. However, only a fraction of cases copresent with alopecia, suggesting alternative etiologies. Our findings suggest baricitinib as a potential treatment, particularly in AA-associated cases of canities subita. Further research is warranted to explore the efficacy and mechanisms of baricitinib in treating this condition.