"COVID toes": A meta-analysis of case and observational studies on clinical, histopathological, and laboratory...

Coronavirus disease (COVID-19) is related to several extrapulmonary disorders; however, little is known about the clinical, laboratory, and histopathological characteristics of pernio-like skin lesions associated with COVID-19 infection.

To evaluate and summarize the clinical, laboratory, and histopathological characteristics of pernio-like lesions reported in the literature.

We conducted a search of the PubMed, SciELO, and ScienceDirect databases for articles published between January 1, 2020 and November 30, 2020, following the PRISMA recommendations (PROSPERO registration ID: CRD42020225055). The target population was individuals with suspected or laboratory-confirmed COVID-19 with pernio-like lesions. Observational studies, research letters, and case/series reports were all eligible for inclusion. Observational studies were evaluated using a random-effects model to calculate the weighted mean prevalence, overall mean, and 95% confidence interval. We evaluated case studies using the chi-square test for dichotomous variables and the Mann-Whitney test for continuous variables.

A total of 187 patients from case reports and 715 patients from 18 observational studies were included. The mean age of patients was 16.6 years (range 14.5-18.8). Feet were affected in 91.4% (87.0-94.4%) of patients in observational studies. The proportion of patients with a positive RT-PCR test was less than 15%. Lesion topography and morphology were associated with age.

Lesions mostly occurred in pediatric patients, and the morphological characteristics tended to differ between pediatric and non-pediatric populations. There is a possible multifactorial component in lesion pathophysiology. The non-positivity of laboratory tests does not exclude an association with COVID-19. Pernio-like lesions may be a late manifestation of COVID-19.