ABSTRACT
The expansion of the COVID-19 pandemic has been accompanied by numerous reports of chilblain-like lesions (CLL) in different countries; however, the pathogenesis of these lesions is still unclear. This systematic review and meta-analysis aimed to assess the prevalence of COVID-19 (diagnosed using PCR and/or serology) in patients with CLL. We undertook a literature search in PubMed, Embase, and Scopus (to 15 March 2021), including studies that reported on the number of patients with CLL with positive PCR and/or serology for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or with a clinical suspicion of COVID-19. Regardless of data heterogeneity, a random-effects model was used to pool prevalence estimates. The meta-analysis included 63 original studies, involving 2919 cases of CLL. A subgroup of these patients underwent diagnostic tests for COVID-19 (PCR: n = 1154, 39.5%; serology: n = 943, 32.3%). The pooled prevalence of COVID-19 in the overall sample and in the subgroup who were tested for COVID-19 was, respectively: (i) positive PCR: 2.6% [95% confidence interval (CI) 1.9% to 3.4%] and 5.5% (95% CI, 3.7-7.7%); (ii) positive serology for SARS-CoV-2: 7.2% (95% CI, 4.7-10.2%) and 11.8% (95% CI, 7.9-16.3%); and (iii) positive PCR and/or serology, 15.2% (95% CI, 10.4-20.7%) and 7.5% (95% CI, 5.1-10.3%). Altogether, a small proportion of diagnostic tests for SARS-CoV-2, both PCR and serologies, show positive results in patients with CLL.