What are chilblains (pernio; perniosis):
Chilblains are a painful abnormal reaction of the small blood vessels in the skin when exposed to cold temperatures. Chilblains usually occur several hours after exposure to the cold in temperate humid climates. The cold causes constriction of the small blood vessels in the skin and if rewarming of the skin happens too rapidly, there is leakage of blood into the tissues as the blood vessels do not respond quickly enough to this rewarming. Chilblains are not very common in countries where the cold is more extreme as the air is drier. The living conditions and clothing used in these climates are protective. Chilblains are more likely to develop in those with poor circulation, but chilblains are still common in those with good circulation.

What do chilblains look and feel like:
Chilblains appear as small itchy, red areas on the skin. Chilblains become increasingly painful as they get congested and take on a dark blue appearance. They may also become swollen. As they dry out, chilblains leave cracks in the skin so the risk of getting an infection increases. Chilblains are common on the toes, but can also affect the fingers and the face (especially the nose and ears). Chilblains are also common on areas of the feet exposed to pressure, such as bunions or where the toes are under pressure from tight shoes or where there are corns and callus.

Chilblains start during the winter (when the weather gets colder) – the initial symptoms include burning and itching in the area of the developing chilblain. These symptoms are often intensified when going into a warm room. There is often some swelling and redness. In many cases, the skin over the chilblain can break down and becomes a sore (ulcer). An infection may develop in the chilblain.

Chilblains often occur in some people every year, for the rest of their lives. In other’s, chilblains occur for several years and then just stop occurring. The reason for these patterns of occurrence of chilblains is not known. As they are more common in females, there may be a hormonal influence on the development of chilblains.

What causes chilblains:
Chilblains are more common in those that are just more susceptible to them – the reasons for this are not entirely clear. Factors that contribute to tendency to chilblains include, a familial tendency, poor circulation, anemia, poor nutrition, hormonal changes, some connective tissue disorders and some bone marrow disorders. Damp living conditions may also increase the risk for chilblains.

As a chilblain is an abnormal reaction to cold, these factors above increase the risk that it is going to happen. Chilblains occur when there is too rapid a change from cold to hot, so the chilblains occur after the foot is cold. Some people’s circulation is so sensitive that only small changes in temperature may be enough. A typical history for the development of chilblains is after being outside in the cold, the foot is placed next to a heat source (eg heater) when coming back inside. The small blood vessels do not respond quickly enough to the change in temperature

Chilblains self treatment:
Prevention of chilblains:
Keeping your feet warm is an important way to prevent chilblains – use trousers, high top boots, tights, leg warmers and long, thick woollen socks. If your feet do get cold, allow them to warm up slowly – do not put them straight in front of a source of heat (this gives a chance for the circulation to respond to the warming skin). Do not let the feet become exposed to any source of direct heat (eg a heater), especially if the foot is very cold – this is a common factor causing chilblains. Smoking also interferes with the circulation in the small blood vessels and increases the risk of getting chilblains.

Once a chilblain develops:
* do not rub or scratch chilblains
* avoid direct heat (ie do not expose the feet to a heater), but keep the feet warm by the use of woollen socks and footwear
* use soothing lotions (eg calamine lotion). There are various chilblain creams on the market
* if the skin is broken, use an antiseptic dressing to prevent the chilblains becoming infected
* those with diabetes or poor circulation should see a Podiatrist. The risk of further complications from the chilblains in those with a foot that is ‘at risk’ is too high to delay seeking professional help
* thermal or insulating insoles can help keep the foot warm to prevent chilblains
* lanolin or a similar lotion that is rubbed into the feet will help stimulate the circulation
* there are a number of natural or homeopathic remedies that are recommended for the treatment of chilblains. Some of these do appear to help some people.

Podiatric management of chilblains:
Podiatrists see a lot of people with chilblains in cold humid climates and can give advice beyond what is listed above:
* padding and pressure relief may give some relief for the chilblain symptoms
* topical steroids may need to be used in case of very swollen severe chilblains
* corns and callus are common in the pressure areas where chilblains can occur, so reduction of these will give some pain relief
* heparin ointment may be used in some people to improve the circulation in the area
* a course of UV light at the start of winter in those prone to chilblains has been recommended to help stimulate the circulation in the foot
* a very rare occasions the chilblains may be a symptom of rare medical problems (eg connective tissue disease or a bone marrow disorder)