In March and April 2020, at the peak of the COVID-19 pandemic, several countries imposed lockdown measures. Concurrently, a significant number of chilblains were observed in otherwise healthy adolescents and young adults. The physiopathology of these chilblains has not been completely elucidated and their direct link to COVID-19 remains unconfirmed and debated1 . RT-PCR on nasopharyngeal swabs and anti-SARS-CoV-2 antibodies were negative in most patient series reported2 . Lifestyle changes associated with lockdown - notably increased sedentariness and prolonged barefoot exposure to cold floors - in predisposed subjects (high number of patients with antinuclear antibodies positivity and low BMI) could be a possible explanation for the outbreak of chilblains3,4 . The underreporting of chilblain "outbreaks" in Nordic countries, where strict confinement was not imposed, could also indirectly point towards a link between confinement and chilblains5 .
Chilblains and COVID-19: Can recent epidemiological data shed light on the etiological debate?