COVID-19 Weakly Correlated With Chilblains Incidence

There is a weak correlation for COVID-19 cases with incidence of chilblains, according to a study published online June 23 in JAMA Dermatology.

Patrick E. McCleskey, M.D., from The Permanente Medical Group Northern California in Oakland, and colleagues conducted a retrospective cohort study to examine the potential correlation between COVID-19 incidence and chilblains. Data were included for 780 patients with chilblains reported during the pandemic.

The researchers observed a correlation for COVID-19 incidence with chilblains incidence at 207 location-months (Spearman coefficient, 0.18). Of the 456 patients with chilblains tested during the pandemic, only 3.7 percent were positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and only 2.0 percent were positive for SARS-CoV-2 within six weeks of chilblains diagnosis. Test results from 1.0 percent of patients were positive for immunoglobulin G antibodies to SARS-CoV-2. COVID-19, but not chilblains, disproportionately affected Latinx patients.

"Although this study found a weak geographic and temporal correlation of COVID-19 cases with chilblains cases, these findings may have resulted from behavioral changes," the authors write. "Very few cases of chilblains were positive for COVID-19."