Researchers used noninvasive swabs to collect sebum. (Credit: Getty)

Skin swabs are surprisingly effective at identifying COVID-19 infection, according to new research, offering a route to a noninvasive future for testing for the virus. Researchers used noninvasive swabs to collect sebum — an oily waxy substance produced by the body’s sebaceous glands — from 83 hospitalized patients, some of whom were diagnosed with COVID-19. The team also collected blood and saliva samples for this comparative study.

COVID-19 has been found to significantly change the makeup of lipids (fats and oils) of biofluids such as blood or sebum. By measuring changes in lipids and other metabolites of the samples, the research team observed that (with a 1.0 score being the most accurate and sensitive) blood samples scored 0.97. Skin swab tests scored 0.88, and finally, saliva tests scored 0.80.

The researchers say the findings suggest that skin sebum responds to changes to the immune system in COVID-19 patients. They believe that illness can alter the body’s natural balance across the whole range of biological systems, including skin, digestive health, and others, which can help identify and understand illness better by providing a whole-body atlas of a disease.