Abstract
Alopecia areata (AA) is an autoimmune disease that causes recurrent hair loss. No treatment has been effective in the long term because of the unstable efficacy and possible side effects. AA is primarily driven by Th1-type inflammation, centred around CD8(+) T cells and interferon-γ (IFN-γ). Recent studies have revealed that the Janus kinase (JAK) family is also involved in the pathogenesis of AA, leading to JAK inhibitors emerging as a treatment for AA. We present a case of a 39-year-old Japanese woman with severe AA who exhibited a Severity of Alopecia Tool (SALT) score 80 accompanied by atopic dermatitis (AD). Despite conventional treatments, the condition worsened from a SALT score of 80 to 100. We subsequently attempted treatment with an excimer laser (EL), but no hair regrowth was observed. However, the introduction of 0.5% delgocitinib ointment in combination with EL led to complete hair regrowth beginning 2 months later, with complete remission achieved after 1 year. This case highlights the potential efficacy of combining delgocitinib ointment with EL in treating severe AA, particularly in patients with AD. The findings suggest that this combination therapy may provide a safer and more effective alternative to oral JAK inhibitors. Nevertheless, further studies are needed to elucidate the underlying mechanisms and fully evaluate the therapeutic synergy.