A comprehensive review highlighted the complex relationship between SARS-CoV-2 infections and skin manifestations, revealing both acute and long-term dermatologic impacts linked to immune system responses.
In the study, published in the Journal of Investigative Dermatology, investigators examined 74 peer-reviewed articles to analyze the prevalence, clinical characteristics, and immunopathogenic mechanisms of skin conditions during COVID-19 infections and post-COVID conditions. The findings identified a wide range of cutaneous manifestations, from common rashes to severe lesions, each associated with distinct immunologic pathways.
Morbilliform, papulovesicular, and livedoid/purpuric rashes were attributed to virus-induced endothelial damage and often correlated with moderate to severe disease. Conversely, pseudochilblains (informally known as “COVID toes”) were found to result from exaggerated type I interferon (IFN-1) responses, particularly in patients who were less severely affected by the virus
Over 20% of patients with acute COVID-19 infections were reported to exhibit cutaneous involvement, according to earlier studies. Notably, the prevalence of these conditions varied across COVID-19 waves, appearing more frequently during the Delta variant surge compared with the Omicron wave.
The investigators emphasized that pseudochilblains, often seen in asymptomatic or mild cases, differed mechanistically from other skin manifestations. This condition was linked to a robust IFN-1 response by plasmacytoid dendritic cells, which may have played a protective role.
"Pseudochilblains represent almost 20% of dermatologic manifestations of COVID-19 [infections]. These lesions were mostly reported in asymptomatic patient or patients with mild upper respiratory symptoms, typically children and young adults," detailed lead study author Nesrine Brahimi, of the Temerty Faculty of Medicine at the University of Toronto, and colleagues.
The review also explored dermatologic issues persisting in post-COVID conditions, including chronic inflammatory responses potentially triggered by lingering viral antigens or immune dysregulation.
The study underscored the importance of recognizing the dermatologic manifestations of COVID-19 infections as part of both acute and postviral presentations. Early identification and appropriate management may improve patient outcomes.
Further research is warranted to fully elucidate the pathophysiologic mechanisms and long-term implications of cutaneous COVID-19 conditions.
Full disclosures can be found in the study.
