Response to 'No evidence of SARS-CoV-2 infection by polymerase chain reaction or serology in children with pseudo-chilblain'

Chilblains-Like Lesions in Pediatric Patients: A Review of Their Epidemiology, Etiology, Outcomes, and Treatment

Vascular pathologies associated with SARS-CoV-2 infection are poorly understood. Color and sensory changes to the extremities, often referred to as "COVID toes" or chilblains-like lesions, have been widely reported in children and adolescents since the onset of the pandemic, raising the concern that they could be a vasculitis secondary to the infection. However, it is unclear if the lesions are a result of the infection or an epiphenomenon. Most literature focuses on adults, and while there are reports on children and adolescents, many of them are small. This review will help medical care providers better understand the epidemiology, etiology, outcomes, and potential treatments for chilblains-like lesions seen in children and adolescents during the pandemic.

Are the chilblain-like lesions observed during the COVID-19 pandemic due to severe acute respiratory syndrome coronavirus 2? Systematic review and meta-analysis

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.