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A new systematic literature review suggests that there may be – at most – a weak link between COVID-19 and alopecia areata.
If there is a connection, it's likely not a strong one, said study author Rachel E. Christensen, a graduate student at Rutgers Robert Wood Johnson Medical School, in an interview. "Based on the reported number of cases following COVID-19, alopecia areata appears to be low on the list of common skin manifestations of COVID-19," she said. Of 402 articles screened from three databases in the review, only 11 were identified as related to alopecia areata (AA) and COVID-19, and only 9 of those met the study inclusion criteria. "This number alone highlights the very low number of published articles investigating this connection."
The review was published in JAAD International.
While COVID-19 has been linked to a variety of skin conditions, a 2021 South Korean study of 7,958 cases and 218,779 controls found no connection between infection and AA even after covariates such as age, gender, and income level were taken into account. In a letter to the editor published in 2020, dermatologists in Turkey reported that the percentage of patients with AA at the dermatology outpatient clinic jumped from 0.97% in May 2019 to 1.48% in May 2020. The number of patients in each group wasn't reported.
The investigators launched the systematic review to gain a wider perspective, although there are still limitations. On the one hand, Ms. Christensen said, "we do know that COVID-19, like other viruses, has been linked to various dermatological disorders."
However, "it is difficult to tease apart whether any worsening of alopecia areata we see following COVID-19 is due to the virus itself or the increased psychological burden related to the infection or to the pandemic in general," she said. Indeed, the authors of the report in Turkey attributed the rise in cases to stress.
For the review, the researchers analyzed studies from Italy (four), Turkey (two), Brazil (one), the United States (one), and Poland (one).
Six of the studies reported cases of new-onset AA following COVID-19 infection (seven cases; average age, 37 years; females, three). Another study was a retrospective review of 32 patients with preexisting AA who developed COVID-19; none experienced significant worsening of AA within 6 months.
The review also included a study based on a survey of 389 patients with AA. The investigators found that, at a median 2.14 months after infection, 44% of those who had COVID-19 vs. 12% of those who were COVID negative had a relapse. Finally, a case report noted a patient with preexisting AA whose condition worsened following COVID infection.
The findings suggest that AA "could be a dermatological manifestation of COVID-19, with cases most often appearing 1-2 months following infection," the authors wrote. "However, the heterogeneity of study designs and high proportion of case reports make it challenging to draw any conclusion."
In an interview, dermatologist Brett King, MD, PhD, of the department of dermatology, Yale University, New Haven, Conn., said the review findings suggest that "there is little concern of alopecia areata following COVID infection.
Does new-onset AA happen, and are there exacerbations of preexisting disease related to COVID infection? Probably yes, but rarely."
However, he noted that another form of alopecia, telogen effluvium (TE), is more common after COVID-19 infection. According to King, who was not involved with the systematic review, TE is typically time-limited, compared with AA's more common chronic waxing-and-waning course.
"Distinguishing TE and AA is usually straightforward because AA typically presents with well-circumscribed patches of hair loss," such as circular patches, "while TE manifests as diffuse hair loss," he explained. "Rarely, however, AA does manifest diffuse hair loss without patches, similar to TE. In those cases, it may be difficult to distinguish them. A biopsy may be helpful if there is a question of the diagnosis."
No study funding is reported. The review authors and King report no relevant disclosures.
This article originally appeared on MDedge.com, part of the Medscape Professional Network.
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Cite this: Randy Dotinga. COVID-19–Alopecia Areata Link? Review Doesn't Find Much Evidence - Medscape - Mar 29, 2022.