Abstract
Telogen effluvium (TE) is an acute and diffuse hair loss due to an abnormal increase in telogen hair follicles in response to external or internal factors. Recently, TE attracts global interest as a major cause of hair loss as a sequela of COVID-19. Typically, hair shedding in TE is expected to cease around 3-6 months from the onset with spontaneous hair regrowth, once the triggering factor is eliminated. However, the substantial shedding causes heavy psychological stress on patients, and there is no evidence-based treatment. To assess the usefulness of topical minoxidil, which has been reported to improve the hair cycle, for TE, an open-label, single-arm clinical trial was conducted enrolling 12 Japanese subjects (3 men and 9 women) who were diagnosed as TE by experts. For each subject, 1 mL of 5% topical minoxidil lotion was applied to the entire scalp twice daily for 24 weeks. Phototrichogram detected that the terminal hair (≥ 60 μm in diameter) count markedly increased respectively by 12.55 ± 4.99 hairs/cm(2) at week 4 and 11.20 ± 4.79 hairs/cm(2) at week 12 from baseline. In the hair wash test assessment, nearly 70% of the subjects were evaluated as improved at least by 2 grades in the evaluation scale (more than 100 shed hair decrease in the count) from baseline. Of note, all investigators and subjects reported notable improvement at week 24 respectively in their reported outcomes. Adverse event was minimal and within the known safety profile of topical minoxidil. Self-healing nature of TE and small sample size represented major factors affecting the validity of the study. Considering its safety profile and wide-availability, topical minoxidil lotion may be helpful in the management of TE making the patients reassured at earlier stage of clinical course. Still, it should be noted that this application is an off-label use.