Objective and Subjective Assessments of the Response of Photobiomodulation Therapy Against Alopecia Areata

Background Alopecia areata (AA), a T cell–mediated autoimmune inflammatory disease with an increasing incidence, not only has cosmetic and psychosocial impacts but is also associated with significant psychiatric comorbidities. Aim To investigate the therapeutic response of photobiomodulation therapy (PBMT) against AA. Method This was a one‐group pretest–posttest study in which PBMT (wavelength: 660 nm) was applied to the AA patients’ scalps twice weekly for 12 weeks. Objective and subjective treatment responses were assessed with the Severity of Alopecia Tool (SALT) and the Chinese version of the Dermatology Life Quality Index (DLQI), respectively. Results Of the 30 adults initially recruited, five were excluded because of loss to follow‐up. Finally, 25 individuals, including 11 males and 14 females, participated in the study. Comparison of the SALT scores on the four portions of the scalp (top, back, right side, and left side) demonstrated significant reductions following treatment (all p < 0.001), suggesting notable improvements in hair regrowth. Cohen’s d values showed high therapeutic responses in all four scalp regions in the order of the back (1.56), left side (1.21), right side (1.10), and the top (0.82). The DLQI dropped significantly after treatment ( p < 0.001), indicating remarkable improvements in the quality of life after PBMT. Conclusions PBMT may be a promising noninvasive treatment option for patients with AA without systemic or local side effects.