Abstract and Introduction
Background: Symptoms of SARS-CoV-2 infection have differed during the different waves of the pandemic but little is known about how cutaneous manifestations have changed.
Objectives: To investigate the diagnostic value, frequency and duration of cutaneous manifestations of SARS-CoV-2 infection and to explore their variations between the Delta and Omicron waves of the pandemic.
Methods: In this retrospective study, we used self-reported data from 348 691 UK users of the ZOE COVID Study app, matched 1 : 1 for age, sex, vaccination status and self-reported eczema diagnosis between the Delta and Omicron waves, to assess the diagnostic value, frequency and duration of five cutaneous manifestations of SARS-CoV-2 infection (acral, burning, erythematopapular and urticarial rash, and unusual hair loss), and how these changed between waves. We also investigated whether vaccination had any effect on symptom frequency.
Results: We show a significant association between any cutaneous manifestations and a positive SARS-CoV-2 test result, with a diagnostic value higher in the Delta compared with the Omicron wave (odds ratio 2·29, 95% confidence interval 2·22–2·36, P < 0·001; and odds ratio 1·29, 95% confidence interval 1·26–1·33, P < 0·001, respectively). Cutaneous manifestations were also more common with Delta vs. Omicron (17·6% vs. 11·4%, respectively) and had a longer duration. During both waves, cutaneous symptoms clustered with other frequent symptoms and rarely (in < 2% of the users) as first or only clinical sign of SARS-CoV-2 infection. Finally, we observed that vaccinated and unvaccinated users showed similar odds of presenting with a cutaneous manifestation, apart from burning rash, where the odds were lower in vaccinated users.
Conclusions: Cutaneous manifestations are predictive of SARS-CoV-2 infection, and their frequency and duration have changed with different variants. Therefore, we advocate for their inclusion in the list of clinically relevant COVID-19 symptoms and suggest that their monitoring could help identify new variants.
Skin-related symptoms of SARS-CoV-2 infection were reported in the wildtype wave in 2020 and were notable both for their variety, spanning more than 30 different cutaneous manifestations,[1,2] and for their utility as a presenting symptom of COVID-19 that could lead to testing and diagnosis. Research from our group evaluating the prevalence of cutaneous manifestations in the UK between May and June 2020 found that 9% of users with SARS-CoV-2 infection confirmed by polymerase chain reaction (PCR) reported a skin rash. Moreover, using an independent retrospective survey, we showed that, for 21% of participants, the rash was the first symptom to appear, and in 17% it was the only sign of the infection.
To date, the World Health Organization has identified five variants of concern that have been globally dominant. The Alpha variant (B.1.1.7) became dominant in September 2020, followed by the Beta variant (B.1.351) in May 2020 and the Gamma variant (P.1) in November 2020. Currently, circulating variants of concern are Delta (B.1.617.2) and Omicron (B.1.1.529), whose earliest documented samples were detected in October 2021 and November 2021, respectively. Variants are associated with different clinical presentations, as shown by a study comparing the prevalence of symptoms between the Delta and Omicron waves in the UK. For instance, during the Omicron wave, users were more likely to report sore throat and hoarse voice and less likely to report at least one of the three classic COVID-19 symptoms (i.e. those included in the UK National Health Service guidelines: anosmia, fever and persistent cough) compared with the Delta wave. However, changes in COVID-19 symptoms across variants have not been evaluated for cutaneous manifestations. Anecdotally, dermatologists have noted fewer consultations for rashes during the Delta and even fewer during the Omicron wave, but data are needed to formally assess how cutaneous manifestations of SARS-CoV-2 infection have changed with the different variants.
In this retrospective study, we report on the diagnostic value, frequency and duration of five cutaneous manifestations (acral, burning, erythematopapular and urticarial rash, and unusual hair loss) of SARS-CoV-2 by leveraging longitudinal self-reported information collected via the ZOE COVID Study app during the Delta and Omicron waves. Additionally, we investigated whether vaccination influenced the frequency of skin-related symptoms.
The British Journal of Dermatology. 2022;187(6):900-908. © 2022 Blackwell Publishing