COVID-19 May Increase Risk of Vitiligo, Chronic Urticaria, Alopecia Areata

COVID-19 infection may raise patients’ risk of developing vitiligo, chronic urticaria, alopecia areata, and herpes zoster, according to recent findings, with higher rates of these skin conditions identified even following multivariable adjustment for confounders.1

These findings on post-infection skin conditions resulted from a nationwide population-based study conducted in South Korea, with the analysis being authored by Min Hee Kim from the department of Ophthalmology, Otolaryngology and Dermatology of Korean Medicine at Kyung Hee University Hospital.

There are a variety of case reports that have been recently released which highlight skin-related complications linked to COVID-19.2 However, Kim noted that research into long-term dermatological conditions that had been potentially triggered by COVID-19, a category distinct from such skin symptoms which immediately occurred after infection, had been lacking.

“While the immediate public health impact of COVID-19 infection has decreased since the pandemic, the long-term complications following infection continue to cause global distress,” Kim and colleagues wrote. “Therefore, research into these post-infection sequelae remains crucial.”1

Trial Design Details

The investigators noted that the healthcare system used in South Korea involves an enrollment of approximately 97% of its citizens in national health insurance, adding that the remaining 3% are supported by a medical aid program. Both of these healthcare programs are integrated into the Korean National Health Insurance Service (NHIS), an organization that provides an extensive dataset for the purposes of assessing the country’s health landscape.

The NHIS’s specialized health information database was utilized for Kim and colleagues’ analysis, with data on different procedures conducted, prescriptions, and surgeries being available thanks to the NHIS and the Korea Disease Control and Prevention Agency. Both have been actively facilitating access to COVID-19-related information to advance medical research, so Kim et al. relied on the NHIS-COVID-19 cohort database spanning from April 2020 - September 2022.

The investigators noted that up until March 2022, diagnoses of COVID-19 in the country had depended exclusively on RT-PCR testing, adding that positive rapid antigen test results were also deemed diagnostic by March. For the purposes of diagnostic consistency, the team’s analysis was restricted to cases confirmed via RT-PCR up until March 13, 2022.
Overall, the researchers included individuals with diagnoses of COVID-19 from April 2021 - March 2022 as participants in their evaluation of skin-related conditions associated with the infection. They randomly selected around 5 million individuals, given the vast volume of data available, with the study’s aim set on any relationships observed between COVID-19 and 4 dermatological conditions: vitiligo, chronic urticaria, alopecia areata, and herpes zoster.

The research team matched the electronic health records for 5,003,010 with records for 5,022,126 control patients, observing both cohorts until September 2022. After making adjustments for various factors such as sex, year of their diagnosis, age, level of income, and residence, the team involved 4,948,016 subjects from each cohort in their final analysis.

Notable Findings

Altogether, the participants involved in the investigative team’s research accounted for 19.15% of South Korea’s 2022 population. The team’s univariate analysis demonstrated that there had been an increased risk of developing vitiligo (HR 1.12, 95% CI 1.06–1.18, P < .0001), developing chronic urticaria (HR 1.12, 95% CI 1.10–1.14, P < .0001), developing alopecia areata (HR 1.17, 95% CI 1.14–1.20, P < .0001), and developing herpes zoster (HR 1.18, 95% CI 1.16–1.19, P < .0001) among those with COVID-19 versus the control arm.

Following their multivariable analyses, during which the investigators adjusted for confounding factors, they aligned with these trends: vitiligo (HR 1.15, 95% CI 1.06–1.24, P = .0006), chronic urticaria (HR 1.13, 95% CI 1.10–1.16, P < .0001), alopecia areata (HR 1.14, 95% CI 1.09–1.18, P < .0001), and herpes zoster (HR 1.15, 95% CI 1.13–1.17, P < .0001).

Overall, the investigators’ findings suggest a major spike in the incidence of the aforementioned dermatological conditions after infection with COVID-19. The team noted that shared risk factors including female sex, advanced age, and obesity were highlighted as potential contributors to the overlap between COVID-19 and these conditions.

Given their statistical adjustments and the inclusion of a washout period, the researchers still managed to isolate an authentic rise in reported new-onset dermatological diseases in the COVID-19 cohort.

“These findings offer valuable insights into the effects COVID-19 may have on the immune system and highlight the need for heightened awareness of skin-related autoimmune conditions in the aftermath of a COVID-19 diagnosis,” they wrote. “While this study identifies a correlation between COVID-19 and dermatological conditions, further research is needed to explore the causal mechanisms in greater detail.”1

References

1. Kim MH. Epidemiological insights into chronic urticaria, vitiligo, alopecia areata, and herpes zoster following COVID-19 infection: A nationwide population-based study. J Dermatol. 2024; 00: 1–6. https://doi.org/10.1111/1346-8138.17600.
2. Martora F, Villani A, Fabbrocini G, Battista T. COVID-19 and cutaneous manifestations: a review of the published literature. J Cosmet Dermatol. 2023; 22: 4–10.