The advent of a new viral disease in the ongoing COVID-19 pandemic has brought new clinical challenges, both in diagnosis and management and also in the pathophysiological association of ‘unusual’ or ‘unexpected’ presentations. Three zoonotic global coronavirus outbreaks have occurred over the last two decades. Severe acute respiratory syndrome (SARS) was first recognised in China in 2002 and identified as being due to SARS-CoV. This was followed by Middle East respiratory syndrome (MERS), colloquially known as ‘camel flu’, detected in Saudi Arabia 2012 and caused by MERS-CoV. The latest is COVID-19, which is caused by SARS-CoV-2 and originated in Wuhan, China, in 2019 (Rongioletti, 2020).
The first COVID-19 (SARS-CoV-2) case, as reported by the South China Morning Post, was detected on 17 November 2019 and allegedly arose from a Chinese seafood and poultry market. The first death from this virus in China was reported on 11 January 2020. To date, COVID-19 has affected well over 10 million people globally and caused the death of more than 500 000 people. The common symptoms of COVID-19 are: high temperature, new continuous cough, shortness of breath/breathing difficulties and body aches and pains. Multi-organ involvement can occur in severe cases (Wang et al, 2020).
With what is in effect a new disease, there was a delay in recognising and reporting dermatological features linked to COVID-19. Subsequently, a wide variety of skin signs and symptoms have been reported. It is interesting to note that with SARS/MERS there is a complete lack of cutaneous manifestations. Conversely, a raft of skin symptoms has been described in relation to SARS-CoV-2. For example, pseudo-chilblain-like lesions of the feet or hands, livedoid or necrotic lesion, and vesicular eruptions have been reported from Italy (Rongioletti, 2020).
Following a literature review, an international group of researchers from Italy, Israel and Canada identified the most common cutaneous manifestations of COVID-19 to be maculopapular exanthem (morbilliform). Other signs included: a papulo-vesicular rash, painful acral purple papules, livedo reticularis lesions and petechiae (Sachdeva et al, 2020).
‘There was a delay in recognising and reporting dermatological features linked to COVID-19. Subsequently a wide variety of skin signs and symptoms have now been reported’
Using a nationwide case collection survey of images and clinical data a Spanish group has reported five major clinical patterns of COVID-19 cutaneous manifestations following a review of 375 patients (Galván Casas et al, 2020). These groups of symptoms have been edited for the sake of brevity.
Interestingly, an increase in herpes zoster was perceived in patients with COVID-19, suggestive of an immunosuppressive component of the COVID diathesis.
With increasing understanding of pathological changes related to COVID-19 we are now enabled to recognise cutaneous changes and attribute them, where appropriate, to the coronavirus. For example, sepsis has been linked to SARS-CoV-2 in some cases, thus a new presentation of skin mottling or rash may herald a serious systemic emergency. It is also known that the virus can cause disseminated intravascular coagulation (DIC) in a fashion similar to meningococcal disease. Early DIC presents with cutaneous manifestations, such as purpura, purpura fulminans, livedo reticularis, livedo vasculopathy (atrophie blanche), anetoderma, chronic venous ulcers, and superficial venous thrombosis(Thornsberry et al, 2013).
In summary, the association of new cutaneous changes in a patient already showing signs of viral illness is perhaps a valuable adjunct in COVID-19. However, reliance on skin changes alone is not reliable for diagnosis—most patients will continue to be uncomplicated with age-related and anticipated changes requiring only symptomatic treatment. Not every new skin manifestation is down to COVID-19.