COVID-19 infection is a major cause of acute telogen effluvium

Acute telogen effluvium is a non-scaring hair loss, usually occurs 3 months after the stressful event that causes hair shedding, and lasts up to 6 months. It can be associated with post COVID-19 infection.

To study the possible effects of COVID-19 on the hair growth cycle and the relationship between COVID-19 and acute telogen effluvium.

This is an observational cross-sectional study that had been conducted during the period from September 2020 to March 2021 years. Thirty-nine patients with post COVID-19 hair loss are confirmed by polymerase chain reaction (PCR) or antibody testing. Hair pull test was carried out to confirm the diagnosis and severity of telogen effluvium.

Thirty-nine patients were evaluated; their ages ranged from 22 to 67 years with a mean and SD of 41.3 ± 11.6 years with 36 (92.3%) females and 3 (7.69%) males. All patients with a diagnosis of ATE were enrolled in this study and had a laboratory-confirmed diagnosis of prior SARS-CoV-2 infection; 15 (38.46%) patients reported mild symptoms, 24 (61.53%) patients presented with moderate disease, and no patient required hospitalization. They all experienced excessive hair loss within 2-3 months after infection. Pull tests were strongly positive (> 10-50% with a mean of 35% of pulled hair away from scalp).

COVID-19 infection is now a frequent and a common cause of acute telogen effluvium. Hence, clinicians should be aware about the relation between this infection and this pattern of hair loss. Drugs that have been used for the treatment of COVID-19 were excluded as a cause of acute telogen effluvium.