Most chilblains observed during the COVID‐19 outbreak are not linked to COVID‐19 infection

Abstract

COVID‐19 is an infectious disease due to a coronavirus called SARS‐CoV‐2. First cases were first reported in Wuhan, China then infection has subsequently spread to the rest of the world. Beside the main signs of the infection (fever, cough, and difficulty breathing), diverse types of skin manifestation (signs) were reported. The most frequently reported type is characterized by red / purple toes, similar to chilblains – a skin disorder usually linked to exposure to cold temperatures. These ‘acral lesions’ that have been linked to COVID‐19 are mainly observed in adolescents and young adults and are clinically described as ‘pseudochilblains’.We conducted, on behalf the French Society of Dermatology, a national survey from March 30 to May 4 2020, asking physicians to report cases of skin manifestations in patients with suspected or confirmed COVID‐19 by using a standardized questionnaire. In this study we report the results relating to manifestations located on hands and/or feet.Among the 311 collected cases of manifestations located on hands and/or feet, 58.5% occurred in women and the median age was 25.7 years. The most frequent clinical presentation was typical chilblains. In total, one third of patients showed classical signs of COVID‐19, 22% only had less specific infectious symptoms, and a half had no clinical signs preceding or during the course of the skin manifestation.The majority of tested patients had no evidence of SARS‐CoV‐2 infection, with 70 out of 75 patients having a negative serology. Serology detects antibodies against the virus (a positive serology allows doctors to conclude that the patient has been infected, while negativity is a strong argument to conclude that the patient was never infected by this virus). 114 out of 121 patients had a negative RT‐PCR (this test detects genetic material of the virus and a positive test shows an ongoing COVID 19 infection).The results of this survey do not rule out that COVID‐19 could be directly responsible for some cases of chilblains, but we found no evidence of SARS‐CoV‐2 infection in a large majority of patients with hand and/or feet skin manifestations during the COVID‐19 lockdown period in France. Linked Article: Le Cleach et al. Br J Dermatol 2020; 183:866–874.