Marie Donlon | July 19, 2022

A team of researchers from the University of Surrey in the U.K. are suggesting that skin swabs are effective at identifying COVID-19 infection in patients.

When measured against the collection of blood and saliva, the non-invasive swab collection of sebum — the oily and waxy substance produced by the sebaceous gland — proved to be nearly as effective at identifying the presence of COVID-19 in infected patients.

Although blood samples are considered the most accurate test for COVID-19, the researchers discovered that COVID-19 changes the composition of lipids (oils and fats) of biofluids, including blood and sebum. As such, the researchers determined that skin sebum responds to changes in the immune system of those with COVID-19 and is thus capable of revealing if a patient is infected.

The researchers measured the changes in the lipids and other metabolites of the blood, saliva and sebum samples taken from more than 80 patients in a hospital setting. The team found that — with a score of 1.0 being the most accurate and sensitive — blood samples scored 0.97, skin swab tests scored 0.88 and saliva tests scored 0.80.

The study, An integrated analysis and comparison of serum, saliva and sebum for COVID-19 metabolomics, appears in the journal Scientific Reports.