COVID toes: where do we stand with the current evidence?

Background: Numerous of cases of chilblains have been observed, mainly in young subjects with no or mild symptoms compatible with COVID-19. The pathophysiology of these lesions is still widely debated and an association with SARS-CoV-2 infection remains unconfirmed. Objectives: This paper focus on the unresolved issues about these COVID toes and in particular whether or not they are associated with COVID-19. Arguments: - The temporal link between the outbreak of chilblains and the COVID-19 pandemic is a first suggests a link between the two events. Journal Pre-proof 3 - Positive anti-SARS-CoV/SARS-CoV-2 immunostaining on skin biopsy of chilblains seem to confirm the presence of the virus in the lesions, but lack specificity and must be interpreted with caution. - Conversely, RT-PCR and anti-SARS-CoV-2 serology were negative in the majority of patients with chilblains. Therefore, SARS-CoV-2 infection can be excluded, with relative certainty, even after accounting for possible lower immunization in mild/asymptomatic patients and for some differences in sensitivity/specificity between the tests used. - Some authors hypothesize that chilblains could be the cutaneous expression of a strong type I interferon (IFN-I) response. High production of IFN-I is suggested to be associated with early viral control and may suppress antibody response. However, the absence of other cutaneous or extracutaneous symptoms as observed in other interferonopathies raises unanswered questions. - To date, a direct link between chilblains and COVID-19 still seems impossible to confirm. A more indirect association due to lifestyle changes induced by lockdown is a possible explanation. Improvement of chilblains when protective measures were adopted and after lifting of lockdown, support this hypothesis. Conclusion: Conflicting current evidence highlights the need for systematic and repeated testing of larger numbers of patients and the need for valid follow-up data that take into consideration epidemic curves and evolution of lockdown measures.

• Tipo de recurso: Article of investigation
• Fecha de publicación: 2020
• Institución: Universidad de Bogotá Jorge Tadeo Lozano
• Repositorio: Expeditio: repositorio UTadeo
• Idioma: eng
• OAI Identifier: oai:expeditiorepositorio.utadeo.edu.co:20.500.12010/14779
• Acceso en línea: https://doi.org/10.1016/j.ijid.2020.10.021; http://hdl.handle.net/20.500.12010/14779
• Palabra clave: COVID-19; SARS-CoV-2; Chilblains; COVID toes; Acral lesions; Serology tests; RT-PCR; Pandemic; Síndrome respiratorio agudo grave; COVID-19; SARS-CoV-2; Coronavirus
• License: Abierto (Texto Completo)