Male baldness may be a risk factor for symptomatic coronavirus disease (COVID-19) infection, according to study data published in the Journal of the American Academy of Dermatology. Compared with men of the same age with no hair loss, men with “severe” hair loss were significantly more likely to test positive for COVID-19.
Investigators assessed hair loss patterns in 1941 men hospitalized for COVID-19 using data from the UK Biobank, which houses the demographic and clinical information of more than 500,000 individuals. At Biobank intake, men were asked to categorize their hair loss using images adapted from the Hamilton-Norwood scale. The scale had 4 options: (1) “no hair loss”; (2) “slight hair loss”; (3) “moderate hair loss”; and (4) “severe hair loss.” Hair loss data were compared in patients with a positive COVID-19 test (n=336) and patients with a negative test (n=1605). COVID-19 test results were also extracted from the UK Biobank. Multivariable logistic regression was conducted to assess the relationship between balding severity and the likelihood of testing positive for COVID-19. Models were adjusted for age, body mass index, hypertension, dyslipidemia, and diabetes.
Overall, increasing hair loss was positively correlated with COVID-19 infection. Of the 592 patients reporting no hair loss, 15.03% tested positive for COVID-19. Inpatients with “moderate” (n=551) and “severe” (n=394) hair loss, the percentage of positive tests increased to 18.15% and 20.05%, respectively. These trends persisted in regression models: patients who reported “severe” hair loss had significantly increased odds of a positive COVID-19 test compared with patients with no hair loss (adjusted odds ratio, 1.408; 95% CI, 1.004-1.972; P =.0468). However, patients with “slight” or “moderate” hair loss were not significantly more likely to test positive than patients with no hair loss.
Balding data was self-reported and reflects a limitation of the study, cited by the study authors.
The mechanisms through which androgenic alopecia may affect COVID-19 susceptibility remain unclear. Further study is necessary to build on these observations and to identify proper means of intervention. “The large effect of baldness on the risk of COVID-19 suggests that the presence of severe baldness may help clinicians and public health authorities identify and protect those at greatest risk,” the investigators concluded.