Characteristics of hair loss after COVID-19: A systematic scoping review.

Abstract

ObjectiveWhile there are literature reporting increased incidence of hair loss in COVID‐19 patients, insufficient evidence exists on the topic to date. This review aims to identify the existing evidence and clinical characteristics of hair loss with COVID‐19 infection.MethodsFollowing the PRISMA Extension for Scoping Reviews, MEDLINE and EMBASE were searched for all peer‐reviewed articles with relevant keywords including “Alopecia,” “Telogen Effluvium (TE),” and “COVID‐19” from their inception to November 20, 2021.ResultsA total of 26 articles, with 9 observational studies and 17 case reports or series (a total of 58 cases), were included. Most studies dealt with TE. There were no clear trends between COVID‐19 severity and the extent of hair loss. Analysis of the 58 cases also found similar results with most of the cases being female (82.8%), the median onset of hair loss of 2.0 months, and the median time to recovery of hair loss of 5.0 months with a resolution rate of 95%.ConclusionWhile this systematic review revealed uncertainty and a lack of strong evidence regarding the association of COVID‐19 and hair loss, hair loss in COVID‐19 may mainly include TE and be reversible in nature. Future studies are warranted to determine the detailed pathophysiology and risk factors of hair loss in COVID‐19, including possible roles of estrogen, progesterone, and pro‐inflammatory cytokines.