Chilblains 

Chilblains (sometimes referred to as pernio) is a condition that happens when small blood vessels, mostly located in the hands and feet, become inflamed after exposure to cold temperatures or wet weather. This inflammation can result in painful swelling, redness, blisters, and itching of the affected area.¹ 

Aetiology

The exact cause of this condition is unknown. Chilblains typically happen due to the body’s “abnormal reaction” to the cold temperature.  This reaction can lead to vasospasm, which is highlighted as a possible contributor to the development of chilblains. A study examined whether cold-induced vasospasm played a part in causing chilblains and found that all participants with the condition showed vasospasm when their hands were put in ice-cold water. This suggests that vasospasm can contribute to how chilblains develop, so using medications that treat vasospasm could potentially be a good way to also help treat patients with chilblains.² Underlying health conditions can also increase the development of chilblains, such as lupus or certain cancers like leukemia.

Epidemiology

• Mostly common in females who are in their teenage years to early 30s
• The incidence of chilblains has increased since COVID-19. This may be due to individuals self-diagnosing with chilblains or to certain lifestyle changes during the lockdown period, such as spending more time in cold environments with little to no heating, engaging in less physical exercise, or wearing clothing that did not provide adequate warmth⁴ 
• The association between COVID-19 and chilblains is still unknown, however, for cases where there is no exposure to the cold, it should be suspected as “being related to SARS-CoV-2 infection”⁵ 
• Despite chilblains affecting both males and females, studies have shown that there is an increased prevalence in women, which could be due to their choice of clothing⁴ 
• Women showed an increase in blood flow in the fingers when exposed to cold temperatures compared to men, suggesting that it should protect them from developing cold injuries⁴ 
• Despite chilblains arising due to cold temperatures, it is less common in cold countries due to the air being less humid and people adapting their lifestyle, such as better clothing and living conditions⁶

Professions at Higher Risk

The demanding conditions some outdoor professions entail, which are usually characterised by long hours in cold and damp environments, can greatly increase their risk of developing chilblains. 

Outdoor Workers

Certain outdoor workers, like farmers and construction workers, are constantly exposed to prolonged cold and wet environments. This issue has persisted for decades. For instance, a study conducted between 1990 and 1992 examined 426 agricultural workers and found that 7% of them developed chilblains. The researchers had concluded that farmers are particularly affected by dermatological issues due to direct contact with various factors, including wet conditions.³ The prevalence of chilblains is lower in studies examining people who work indoors compared to those who work outdoors.⁴ Another common outdoor profession at risk of chilblains is fishermen and maritime workers. Working in constant dampness, frequent exposure to water, and the lack of warmth contribute to the development of chilblains.⁵ Delivery drivers and transportation workers are also at a heightened risk of chilblains due to the long exposure to wet environments and a lack of clothing. 

Military Personnel

The nature of military service involves training in a wide range of environments, from extreme heat to severe cold. This can increase the risk of conditions such as chilblains, particularly when training in wet and cold environments without proper clothing or equipment. Trench foot and chilblains are among the most common cold-weather injuries faced by military personnel.⁶ According to the military health surveillance 2022 analysis, these injuries were more prevalent in men, non-Hispanic Black service members, and younger personnel under the age of 20. The higher incidence may be attributed to several factors, including underlying medical conditions, lifestyle choices such as smoking or alcohol use, excessive sweating, restrictive clothing, low body fat percentage, or lack of physical activity.⁷ 

Preventive Strategies

Personal Protection

Chilblains symptoms usually settle down after 2-3 weeks of cold exposure. Despite this, several at-home treatments can help relieve symptoms and reduce the risk of developing new lesions. Wearing loose, but warm, layered clothing helps to retain warmth, especially in the feet and hands. It is also important to keep the feet dry, since any type of dampness can worsen the condition and outcomes. Wearing properly fitted footwear that is not too tight is important. Whenever possible, try to avoid being outdoors in cold or damp conditions; however, if you need to go out in these conditions, wearing adequate warm, loose clothing like thick socks and gloves on dry feet and hands can help lower the risk of developing chilblains.

It is important to note that if your hands or feet are cold, do not put them directly on hot surfaces to warm them up like a radiator. Blood vessels are sensitive to rapid temperature changes, so any sudden warming causes them to dilate quickly, which may overwhelm and further damage already inflamed vessels affected by chilblains. Doing this can further worsen the pain, swelling, and vascular damage. To avoid the quick temperature change, warming your hands and feet gradually with warm clothing or soaking them in lukewarm (not hot or cold) water can help to slowly warm affected areas, and is also an effective way to restore warmth safely at a temperature that is acceptable.

Lifestyle Changes

Adopting healthier lifestyle choices, such as not smoking or limiting alcohol consumption, can greatly decrease the risk of chilblains. A Turkish study of 69 chilblain patients found that 31% reported their workplace as the site of exposure, 12% attributed it to being outdoors in cold temperatures, and 16% reported smoking.⁸ Smoking increases the risk because nicotine constricts blood vessels, which can lead to limited or poor circulation. Maintaining a nutritious diet rich in vitamins like B12 can also support vascular health and reduce the vulnerability to cold-weather-related injuries. Regular physical activity can help improve circulation and strengthen blood vessels. Exercise can be as simple as walking around the house to help generate body heat, which is especially beneficial in keeping the hands and feet warm when it comes to chilblains.

Summary

Chilblains are a condition that causes painful swelling in areas, mostly commonly on the feet, but it can also affect the hands and face. It occurs when the blood vessels become inflamed after prolonged exposure to cold and damp environments. Certain outdoor professions are at higher risk of developing chilblains, such as farmers, fishermen, and delivery drivers, as well as any job that involves being outdoors all day, like construction workers. Wearing adequate warm but loose clothing can help to decrease the risk of developing chilblains and also help keep the affected, more vulnerable areas warm. There are many at-home treatments that affected individuals can try, such as gradually warming affected areas by soaking them in lukewarm water, layering clothing, or making lifestyle changes, all of which can help minimise the risk.