Chilblains

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.<ref>Cold Stress: Chilblains. National Institute for Occupational Safety and Health. Retrieved January 6, 2009.</ref>

It occurs most frequently when predisposed individuals, predominantly women,<ref name="What Are COVID Toes? A Case Study">Template:Cite journal</ref> 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.<ref name="What Are COVID Toes? A Case Study"/>

Chilblains can be idiopathic (spontaneous and unrelated to another disease), but similar symptoms may also be a manifestation of another serious medical condition that must be investigated. Related medical conditions include Raynaud syndrome, erythromelalgia, frostbite, and trench foot, as well as connective tissue diseases such as lupus or vasculitis. In infants affected by Aicardi–Goutières syndrome (a rare inherited condition which affects the nervous system) chilblain-like symptoms occur together with severe neurologic disturbances and unexplained fevers.

Signs and symptoms

File:Chilblains from excessively icing the feet.jpg

Chilblains of the feet, caused by excessive exposure to cold and humidity

Dermatitis in extremities (toes, fingers, earlobes, nose, etc), including:

• Burning and itching sensations
• Throbbing pain
• Skin discoloration (red to dark blue) with erythema (blanchable redness)
• Blistering of affected area
• Ulceration (in severe cases only)

Chilblains caused by exposure to cold and humidity can usually heal within 7–14 days.

Prevention

Exposure

• Keep affected area warm, and avoid any extreme temperature changes (including very hot water).<ref name=Harvardweb/><ref name="MNT"/>
• Keep affected area dry.<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

• Wear warm shoes, socks and gloves.<ref name="MNT">{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

• Wear a hat and a scarf to protect the ears and the nose.<ref name="MNT"/>
• Avoid tight fitting socks/shoes.

Other

• Exercise at least four times a week to improve circulation.<ref name="MNT"/>
• Quit smoking, as it damages circulation.<ref name=Harvardweb>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

Treatment

• Nifedipine and amlodipine, which are vasodilators in the class of drugs known as calcium channel blockers, may help in some cases.<ref>Template:Cite journal</ref> Vasodilation may reduce pain, facilitate healing, and prevent recurrences.<ref>Template:Cite journal</ref> It is typically available in an oral pill but can be compounded into a topical formula.
• Diltiazem, a vasodilator, may help.<ref>Template:Cite journal</ref>

Etymology

The word is a compound of Modern English chill ‘cold’ and the archaic word blain (now used only in the word in question), meaning ‘swelling’, ‘blister’ or ‘sore’ and derived from Old English bleġen, bleġene, having the same meaning.<ref>https://en.wiktionary.org/wiki/chilblain Retrieved at 8.45 on Wednesday 20/12/23.</ref>

Alternative remedies

The medieval Bald's Leechbook recommended treating chilblains with a mixture of eggs, wine, and fennel root.<ref>Robert Lacey and Danny Danziger August: The Year 1000: What Life Was Like at the Turn of the First Millennium Little, Brown, 2000 Template:ISBNTemplate:Page needed</ref> A modern-day home remedy is to put garlic on the chilblains.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Other herbal remedies supposed to be vasodilating, rubifacient, and warming, have been recommended.

COVID-19

Chilblain-like symptoms have also been linked to COVID-19.<ref name="Wollina2020">Template:Cite journal</ref><ref name="Young2020">Template:Cite journal</ref><ref name="Kaya2020">Template:Cite journal</ref> COVID toes, as they are commonly known,<ref name="Massey2020">Template:Cite journal</ref><ref name="Bristow2020">Template:Cite journal</ref><ref name=":0">Template:Cite journal</ref> have mostly been reported in older children and adolescents,<ref name="Walker2020">Template:Cite journal</ref><ref name=":0" /> who often have not had other symptoms of COVID-19.<ref name="Ladha2020">Template:Cite journal</ref> The symptoms are usually mild and disappear without treatment.<ref name="Walker2020" /><ref name=":0" /> 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.<ref name="Massey2020" /><ref name="Bristow2020" /><ref>Unusual coronavirus (COVID-19) symptoms: What are they?</ref> They may share some of the microscopic features of chilblains caused by lupus.<ref name="Ladha2020" /> 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.<ref name="Ladha2020" />

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.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

See also

• Equestrian perniosis
• Erythrocyanosis crurum
• Raynaud's disease

External links

• Template:DermAtlas
• Cold stress, National Institute for Occupational Safety and Health