Correspondence Address:
Dr. Chih-Chiang Chen
Department of Dermatology, Taipei Veterans General Hospital, No. 201, Sec. 2, Shipai Road, Beitou District, Taipei City 11217
Taiwan

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Ever since the outbreak of the COVID-19 pandemic in 2019, the dermatology society worldwide has been faced with tremendous challenges.[1] To minimize the risk of COVID-19 transmission, nonurgent outpatient visits were discouraged and the patient volume decreased consequently.[2] Modification of the treatment for dermatological diseases was widely discussed, as some may concern the risk of infection under the usage of immunosuppressants and biologics. Moreover, a variety of cutaneous manifestations were linked to COVID-19 infection, which may even be the preceding signs in some patients.[3] Thus, dermatologists should be aware of these skin findings to enhance diagnostic accuracy in clinical practices.

Commonly reported COVID-19-associated cutaneous manifestations included morbilliform, urticarial, pernio-like, papulosquamous, and papulovesicular skin rash [Figure 1].[4],[5] Pernio-like skin rash, or the so-called “COVID toe,” was commonly reported in western countries, typically presented as violaceous papules and plaques on toes with occasional bullae formation or ulceration.[6] Comparing to other skin findings, pernio-like skin rash was more likely to be found in the younger population and those with mild COVID-19 infection.[4] Morbilliform skin rash and urticarial skin rash, on the other hand, were less specific and found more prevalently in COVID-19 patients with moderate severity. Retiform purpura (thrombotic vasculopathy) may also be observed in patients with COVID-19, especially in those with severe infection and respiratory failure.[4],[5] In children, a so-called “Kawasaki disease-like inflammatory syndrome,” characterized by gastrointestinal symptoms, myocarditis, and even shock, was documented in various countries.[7] Classic skin and mucosal presentations in Kawasaki disease, such as conjunctivitis, polymorphic rash, and erythema and induration over hand and feet, can also be seen in these COVID-19 affected children.[7] Several other mucocutaneous lesions, such as geographic tongue, erythema multiforme, pityriasis rosea, and dengue-like exanthem, had been documented in the literature.[7],[8],[9] Given the diverse skin manifestations of COVID-19, differentiation from other viral exanthems was difficult but crucial in clinical settings.[3],[10] Additional nasopharyngeal and serological viral testing may be helpful to achieve accurate diagnosis.{Figure 1}

Although the number of researches on the skin manifestations related to COVID-19 infection was soaring, most of them were conducted in western countries. To determine the situation in Asian countries, Yildiray and colleagues reported the cutaneous manifestations of COVID-19 in Turkey recently.[11] They discovered five out of 266 patients (1.9%) developed skin lesions, which was much lower than previous reports.[12] Besides, only urticarial and vesicular skin rash were reported in this study. Ethnic differences, the severity of COVID-19 infection and variation of viral genome were possible explanations for the lower prevalence of skin manifestations in Turkey. Given the paucity of data in Asia, a registry-based database was warranted to shed light on the ethnic differences.

Aside from cutaneous manifestations related to COVID-19 infection, recent studies have focused on the skin findings related to the COVID-19 mRNA vaccine (Pfizer and Moderna). McMahon et al. recorded the cutaneous reactions after mRNA-based COVID-19 vaccines and demonstrated that local site reaction, urticarial skin rash, morbilliform skin rash, delayed local reaction, and erythromelalgia were most commonly presented.[13] Swelling of the cosmetic filler injection site was also reported in both vaccines, which was assumed to be caused by the delayed-type hypersensitivity reaction.

As a dermatologist, we should take notice of COVID-19-related skin manifestations and refer to COVID-19 testing if we encountered any suspected patients. Additionally, any skin manifestations in these patients should be recorded to help elucidate the full picture of COVID-19 infection.

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Nil.

Conflicts of interest

There are no conflicts of interest.

References