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.[2]
It occurs most frequently when predisposed individuals, predominantly women,[3] are exposed to cold and humidity. Ulcerated chilblains are referred to as kibes. 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.[3]
Nifedipine and amlodipine, which are vasodilators in the class of drugs known as calcium channel blockers, may help in some cases.[7]Vasodilation may reduce pain, facilitate healing, and prevent recurrences.[8] It is typically available in an oral pill but can be compounded into a topical formula.
The word is a compound of Modern Englishchill ‘cold’ and the archaic word blain (now used only in the word in question), meaning ‘swelling’, ‘blister’ or ‘sore’ and derived from Old Englishbleġen, bleġene, having the same meaning.[10]
The medieval Bald's Leechbook recommended treating chilblains with a mixture of eggs, wine, and fennel root.[11] A modern-day home remedy is to put garlic on the chilblains.[12] While neither of these remedies has been supported by scientific research, vasodilating, rubiefacient and warming herbal remedies, both topical and internal are prescribed and efficacious.
Chilblain-like symptoms have also been linked to COVID-19.[13][14][15]COVID toes, as they are commonly known,[16][17][18] have mostly been reported in older children and adolescents,[19][18] who often have not had other symptoms of COVID-19.[20] The symptoms are usually mild and disappear without treatment.[19][18] Their cause is debated: it is uncertain whether COVID toes are a delayed consequence of the viral infection itself or are, at least partially, connected to environmental factors during the COVID-19 pandemic.[16][17][21] They may share some of the microscopic features of chilblains caused by lupus.[20] It has been suggested that in the absence of exposure to cold and damp, COVID-19 should be considered as a possible cause of chilblains.[20]
In a study at the dermatology department of Saint-Louis Hospital in Paris, researchers found that most of their study participants carried high levels of autoantibodies, proteins generated by the immune system that inadvertently attack the body's own tissues. Compared with healthy individuals, the participants showed high activity of proteins called type 1 interferons, which switch on pathogen-fighting genes in immune cells.[22]
^James, William D.; Elston, Dirk M.; Treat, James R.; Rosenbach, Misha A.; Neuhaus, Isaac M. (2020). "Dermatoses Resulting From Physical Factors". Andrews' Diseases of the Skin (13th ed.). Elsevier. pp. 18–45. ISBN9780323547536.
^Cold Stress: Chilblains. National Institute for Occupational Safety and Health. Retrieved January 6, 2009.
^Rustin, M.H.A.; Newton, Julia A.; Smith, N.P.; Dowd, Pauline M. (2006). "The treatment of chilblains with nifedipine: the results of a pilot study, a double-blind placebo-controlled randomized study and a long-term open trial". British Journal of Dermatology. 120 (2): 267–75. doi:10.1111/j.1365-2133.1989.tb07792.x. PMID2647123. S2CID13230013.
^Robert Lacey and Danny Danziger August: The Year 1000: What Life Was Like at the Turn of the First Millennium Little, Brown, 2000 ISBN0316511579[page needed]
