BREAKING: COVID-19 Vaccination — Not Infection — Increases Risk of Multiple Hair Loss Disorders

by Nicolas Hulscher, MPH

A massive Korean nationwide study published in Annals of Dermatology has found that COVID-19 vaccination — but not COVID-19 infection — significantly increases the risk of hair loss disorders, including complete hair loss (alopecia totalis), patchy autoimmune hair loss (alopecia areata), and excessive shedding (telogen effluvium).

Using over 5.7 million individuals from the National Health Insurance Service database, researchers investigated the risks of new-onset alopecia during 2021, adjusting for demographics (age, sex, income) and comorbidities.

KEY FINDINGS

COVID-19 infection

• Slightly increased risk of total alopecia (aOR 1.076) but not significant after statistical matching.

• No significant association with alopecia areata or telogen effluvium.

COVID-19 vaccination

• Alopecia totalis (complete hair loss): aOR 1.266 (26.6% increased odds, p<0.0001)

• Alopecia areata (patchy autoimmune hair loss): aOR 1.243 (24.3% increased odds, p<0.0001)

• Telogen effluvium (hair shedding): aOR 1.495 (49.5% increased odds, p=0.005)

• Associations held true even after adjusting for infection status, comorbidities, and using matched datasets.

• Androgenetic alopecia also increased (aOR 1.726) in vaccinated individuals in matched analysis.

Mechanistic hypotheses

• Autoimmune triggers from spike protein immune responses.

• Molecular mimicry between spike protein and human hair follicle components.

• Systemic inflammatory and immune stress responses as possible telogen effluvium triggers.

This is the largest population-level evidence to date linking COVID-19 vaccination to increased risk of multiple hair loss disorders. This study corroborates Kim et al, who found among 1,748,136 Koreans that vaccinated individuals were 2.4 times more likely to develop hair loss than those who were not vaccinated:

Hair loss is something no one wants to experience — it can take a heavy emotional and psychological toll, affecting self-esteem, social confidence, and even mental health. While some forms such as telogen effluvium may be temporary, others like alopecia totalis can be long-lasting or permanent.

Nicolas Hulscher, MPH

Epidemiologist and Foundation Administrator, McCullough Foundation

www.mcculloughfnd.org

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