09 May 2020
The Covid-19 pandemic has created unprecedented challenges in Singapore and the world. Since the discovery of Covid-19 virus from Wuhan, China in late December 2019, the novel coronavirus (SARS-CoV-2) has spread globally leading to global movement restrictions for the first time in modern history. Our knowledge of the novel coronavirus is also still growing. As doctors and scientists race to unravel more about Covid-19 and hopefully, develop a vaccine and/or cure for Covid-19.
Many of us are familiar with the typical symptoms of Covid-19 infection. The common symptoms of coronavirus infection include fever; cough; shortness of breath; loss of smell and taste; and tiredness. One of the more recent discoveries of Covid-19 is its possible skin manifestations. In recent weeks, rashes and skin findings have merged as potential signs of Covid-19 infection.
Many viral infections besides Covid-19 can be accompanied by rashes. Some of these rashes can have characteristic appearances and behaviours. Examples of viral infections with tell-tale appearances are chicken pox and measles. On the other hand, some of the rashes may have less specific features, making it difficult to diagnose the infection.
Similarly, the presence of a rash does not necessarily indicate the presence of an infection. Rashes can also be caused by allergies, heat and inflammatory disorders. Most rashes are not dangerous or life threatening. However if the rash is persistent, painful, infected or associated with a fever; please see your doctor to get your rash treated.
The first journal publication of Covid-19’s skin manifestation was in late March by an Italian doctor. He analysed 88 patients infected with Covid-19 in Lombardy, Italy1. In this study, 20% of patients infected with Covid-19 had skin conditions; mainly red rashes involving the trunk1.
In a more recent publication in the British Journal of Dermatology, Spanish dermatologists analysed the skin findings in 375 patients infected with Covid-19. This study found 5 dermatological conditions linked to coronavirus infection2. One common skin change in 19% of patients was redness and swelling of the hands and/or feet (pseudo-chilblain)2. Pseudo-chilblain looks like frostbites and affects younger patients. The presence of pseudo-chilblain was associated with less severe disease2.
Another finding in the skin in this Spanish study was vesicular lesions (fluid filled blisters)2. Other signs included urticarial rash (similar to hives) and maculopapular rashes (flat or raised red rashes)2. The last skin symptom related to Covid-19 was a reddish-purple discolouration called livedo reticularis. This finding of pseudo-frostbites, hives and redness in infected patients was also reported by French National Union of Dermatologists-Venereologists (SNDV) organization2.
“Covid toes” are increasingly being reported in the media as an indication of Covid-19 infection. Although dubbed Covid toes, the findings are similar to the pseudo-chilblain or pseudo-frostbite symptoms reported by the Spanish, Italian and French doctors1-3 .
Preliminary research into Covid toes suggest that an increase in blood clots blocking off blood supply to the toes4.
The Covid-19 pandemic is far from over, at least in Singapore. Dermatological findings of Covid-19 infection are increasingly being reported, with Covid toes being more commonly reported worldwide.
There are 5 main characteristic rashes linked to Covid-19 infection. Covid toes or pseudo-frostbite (pseudo-chilblain), urticarial rashes and red rashes are the most common findings. These findings may provide clues about Covid-19 infection in situations when diagnostic test kits are limited. That said, rashes are common and may not be related to coronavirus infection, so it is important not to self diagnose. If in doubt, please check with your doctor
1. Cutaneous manifestations in COVID-19: a first perspective. Recalcati. J Eur Acad Dermatol Venereol.
2. Classification of the cutaneous manifestations of COVID-19: a rapid prospective nationwide consensus study in Spain with 375 cases. Galván et al. Br J Dermatol. 2020 Apr 29.
4. Complement associated microvascular injury and thrombosis in the pathogenesis of severe COVID-19 infection: a report of five cases. Magro et al. Transl Res. 2020 Apr 15.