Chilblains, also known as pernio, is a medical condition in which damage occurs to capillary beds in the skin, most often in the hands or feet, when blood perfuses into the nearby tissue, resulting in redness, itching, inflammation, and possibly blisters.

Temperature-related chilblains can be prevented by keeping the feet and hands warm in cold weather and avoiding exposing these areas to extreme temperature changes.

Once the diagnosis of chilblains is made, first-line treatment includes avoiding cold, damp environments and wearing gloves and warm socks.

Related medical conditions include Raynaud syndrome, erythromelalgia, frostbite, and trench foot, as well as connective tissue diseases such as lupus or vasculitis.

Compared with healthy individuals, the participants showed high activity of proteins called type 1 interferons, which switch on pathogen-fighting genes in immune cells.