Synthesis of the Data on COVID-19 Skin Manifestations: Underlying Mechanisms and Potential Outcomes

Abstract

The incidence of coronavirus disease 2019 (COVID-19)-related skin manifestations has progressively grown, in parallel with the global severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spreading. The available evidence indicates that cutaneous signs are heterogeneous and can be divided as follows: a) erythematous rashes, b) lesions of vascular origin, c) vesicular rashes, d) urticarial rashes, and e) acute generalized exanthematous pustulosis (AGEP), erythema multiforme (EM) and other polymorphic/atypical reactions. Most cutaneous manifestations appear simultaneously or after respiratory and/or systemic symptoms such as fever, even if rarely urticaria has been reported as the first sign of the disease. It has been proposed that erythematous and vesicular rashes, as well as urticaria, are the result of immunological activation against Sars-CoV-2, similarly to other viral exanthems; alternatively, reactivation or co-infection of herpesviruses and drug hypersensitivity represent possible etiologic diagnosis that has to be considered. Regarding lesions of vascular origin, ischemic ones are the result of systemic hypercoagulability established in severe infections, whereas chilblains seem to be linked to the type I-interferon massively produced to halt virus replication. AGEP is triggered by drugs, whereas EM could represent a delayed immune response to the virus or a hypersensitivity reaction to drugs elicited by the inflammatory process built to fight the infection. A further pathogenic hypothesis is that the virus, or its particles detected in the skin (particularly in endothelium and eccrine glands), could be responsible for certain skin reactions, including chilblains and EM. From the available data, it appears that chilblains are correlated with younger age and less severe disease, while ischemic manifestations occur in the elderly with severe infection. In conclusion, larger studies are needed to confirm the suggested pathogenetic mechanisms of COVID-19-related skin reactions and to determine the potential prognostic significance of each one.

COVID-19 detection using a model of photoplethysmography (PPG) signals

“…In particular, our results suggest that SARS-CoV-2 infection can lead to a “damper” microcirculatory response. The damping of the shape of the curve along with minor slopes confirms the possible effect of vasoconstriction that these patients may show [28] , [29] . This condition can be the result of endothelial damage and cytokine storm induced over time by the SARS-COV-2 infection [4] , [10] , [30] .…”

Smoking increases the risk of post-acute COVID-19 syndrome: Results from a French community-based survey

“…This result is not surprising as female gender is currently considered a non-equivocal predicting factor for ‘long COVID’ 20 - 22 . Moreover, it is well known that autoimmune diseases and allergies are more frequent in women than men 25 , 26 , and cutaneous manifestations following COVID-19 are often of a pseudo-allergic or vascular type 27 . Further studies investigating the underlying mechanisms of cutaneous manifestations following SARS-CoV-2 infection could be helpful to explain the relationship between cutaneous manifestations and female gender.…”

Skin manifestations in patients with coronavirus disease 2019

“…Livedo reticularis/racemosa-like pattern is rarely found in COVID-19 patients (from 0.6 to 3.5% of different series) but livedo racemosa-like lesions have been frequently reported in patients with severe coagulopathy [7,51]. Histology shows a pauci-inflammatory microthrombotic vasculopathy, similar to the 'Chilblain-like pattern' [32 && ,48].…”