Association between alopecia areata and COVID-19: A systematic review

BACKGROUND: COVID-19 may play a role in various immune-related dermatologic conditions. The relationship between COVID-19 and alopecia areata remains unclear. OBJECTIVE: To review the existing literature for clinical studies and reports investigating the association between new-onset alopecia areata or the exacerbation of preexisting alopecia areata following infection with SARS-CoV-2. METHODS: A systematic review of the literature was performed using PubMed, Embase, and MEDLINE databases from inception to October 2021. Included articles assessed alopecia areata following infection with SARS-CoV-2. RESULTS: Of 402 total articles, 9 were identified as meeting the inclusion criteria. Six articles described case reports of 7 patients with new-onset alopecia areata following confirmed infection with SARS-CoV-2, and 3 articles reported on alopecia areata recurrence or exacerbation following SARS-CoV-2 infection in patients with preexisting disease. Studies investigating the exacerbation or recurrence of alopecia areata following infection reported mixed findings. LIMITATIONS: A majority of the included studies were case reports. The heterogeneity of articles precluded data synthesis. CONCLUSION: Alopecia areata may be a dermatologic manifestation of COVID-19, with cases most often appearing 1 to 2 months following infection. Additional research is necessary to better elucidate the relationship and draw conclusions.