A systematic review of acute telogen effluvium, a harrowing post‐COVID‐19 manifestation

This systematic review focuses on the clinical features, physical examination findings, outcomes, and underlying pathology of acute telogen effluvium (TE), a type of diffuse hair loss, occurring in coronavirus disease 2019 (COVID-19) recovered patients. MEDLINE/PubMed and Embase databases were queried till October 2021 to identify studies reporting acute TE occurring after COVID-19 recovery. Data were obtained from 19 studies, which included 465 patients who were diagnosed with acute TE. The median age of these patients was 44 years and 67.5% were females. The most common trichoscopic findings were decreased hair density, the presence of empty follicles, or short regrowing hair. The mean duration from COVID-19 symptom onset to the appearance of acute TE was 74 days, which is earlier than classic acute TE. Most patients recovered from hair loss, while a few patients had persistent hair fall. Our results highlight the need to consider the possibility of post-COVID-19 acute TE in patients presenting with hair fall, with a history of COVID-19 infection, in the context of COVID-19 pandemic. Despite being a self-limiting condition, hair loss post-COVID-19 is a stressful manifestation. Identifying COVID-19 infection as a potential cause of acute TE will help the clinicians counsel the patients, relieving them from undue stress.