Frostbite - Medical Health Care Library Wiki


Main Article	Forum

Frostbite

	Original Author Healthocrates Staff
	Physician/Scientist DRcrumfield
	Health Care Professional No contributions yet. Be the first!
	Contributing Member No contributions yet. Be the first!
	Add New Topic Tab

Winter cold and snow provide a number of opportunities to get outside and participate in activities such as skiing, sledding, and snowmobiling. However, without proper protection, cold weather-related injuries can occur even when temperatures are above freezing (32 F, 0 C). This is especially true if there are high winds or if clothing is wet. In general, however, it is both the temperature and the duration of exposure that play a role in determining the extent and severity of cold weather-related injuries. The information below describes the different types of cold weather-related injuries, as well as what to do to prevent and treat them prior to reaching a healthcare provider.

What type of injuries can be caused by cold weather?

Cold weather-related injuries can be divided into two general categories. These are those that occur without the freezing of body tissue (chilblains and trench foot) and those that occur with the freezing of body tissue (frostbite).

Cold weather-related injuries without tissue freezing:

Chilblains

Chilblains is a common type of cold weather-related injury that can develop several hours after exposure to extreme cold. Chilblains are itchy, painful, reddish, or purplish areas of swelling that usually affect the fingers, toes, nose or ears; though other areas of the body may also be involved. In some individuals, blisters or small open sores may also form. Chilblains usually last for several days, and the affected area usually heals after several weeks. Though the affected area may remain sensitive to the cold in the future, there is usually no permanent damage. It is not uncommon for a recurrence of chilblains in susceptible individuals.

Trench foot (immersion injury)

Trench foot (immersion injury) was named after the condition suffered by many soldiers in the trenches during World War I. Trench foot develops after prolonged exposure to a wet, cold environment and is typically a more serious condition than chilblains. The symptoms of trench foot include:

pain,
numbness, and swelling,
The affected area may appear:
red,
blotchy,
pale,
bluish or even black with advanced injury.

As with chilblains, blisters and open sores can also develop. With severe trench foot, the development of gangrene requiring amputation can also occur. The usual recovery period from uncomplicated trench foot can be for several weeks and as with chilblains, subsequent cold sensitivity of the affected area may also occur.

Cold weather-related injuries with tissue freezing :

Frostbite

Frostbite occurs when there is freezing of the affected area and it is the most serious of the cold weather-related injuries. Frostbite usually affects the hands, feet, nose, or ears; though other parts of the body may also be affected. This type of injury results from decreased blood flow and heat delivery to body tissues resulting in damaging ice crystal formation.

Frostbite injuries can be classified as either superficial or deep depending on the depth of injury. Superficial frostbite injuries involve the skin and subcutaneous tissues, while deep frostbite injuries extend beyond the subcutaneous tissues and involve the tendons, muscles, nerves, and even bone. Superficial frostbite injuries have a better prognosis than deep injuries.

Frostbite symptoms

The symptoms of frostbite may progress from pain/burning to numbness and eventual complete loss of sensation. Depending on the extent and time of injury, the affected area may appear pale, red, bluish/gray or black with the presence of clear or purplish colored blisters. The skin and underlying tissue may feel hard to the touch with advanced injury.

The prognosis for frostbite injuries depends on the extent of injury and whether or not there are any resultant complications from the initial injury, such as infection. It may be weeks to several months before it is possible to determine exactly how much tissue damage has occurred, and what if any tissue needs to be removed/amputated. Sometimes cold sensitivity or numbness of the affected area persists.

Who is most likely to get a cold weather-related injury and what can be done to prevent it?

Anybody can develop a cold weather-related injury, but the young and the elderly are especially prone to these types of injuries. In the young, the small size of their extremities and their limited mobility makes them more likely to be affected while in the elderly, poor circulation and limited mobility increase their susceptibility. Individuals who work outdoors, the homeless, and those who engage in outdoor activities are also at increased risk for developing cold weather-related injuries.

Alcohol and illicit drug use make it more likely that individuals will develop a cold weather-related injury because these people may not sense that they are in danger. Certain medical conditions, such as diabetes, hypothyroidism (low thyroid), psychiatric illness, and circulatory problems can also make it more likely that one will develop a cold weather-related injury.

The prevention of cold weather-related injuries is best achieved through careful preplanning and preparation for the cold, when possible.

Dress warmly using multiple layers and adequately cover body areas prone to injury.
Try to have an extra change of dry clothing so you can remove any wet clothing if necessary.
Always keep your hands and feet dry and avoid wearing tight fitting clothing on these areas as it may decrease the circulation.
Most importantly, however, move indoors to a warmer environment when you begin to feel cold.

How should frostbite and other cold weather-related injuries be treated?

The treatment for cold weather-related injuries involve removing oneself from the precipitating cold environment, with subsequent rewarming of the affected areas using moist heat.
The use of dry heat (such as over a fire or a portable heater) can lead to burns because of ones lack of sensation and it can also further dry out the already injured tissue.
Avoid massaging or rubbing the affected area with snow (a common "folk remedy") as this will only aggravate the injury.

With regard to frostbite, it is important NOT to thaw the affected area if there is a risk of it re-freezing! Re-freezing will only lead to more severe damage. If you are camping or outdoors and you are unable to get indoors, leave the extremity frozen until definitive medical care can be instituted.

Rapid rewarming is the most effective treatment for cold weather-related injuries. This is accomplished by immersion of the affected area into circulating hot water that is between 40 to 42 C (104 to 108 F) for 15 to 30 minutes or until thawing is complete. Make sure to test the temperature of the water with a thermometer or a hand that is not frozen in order to avoid burning the injured area! There may be quite a bit of pain when the injured area is rewarmed. Acetaminophen (Tylenol and others), aspirin (Bayer and others), naproxen (Aleve and others) or ibuprofen (Advil and others) may be used to help with the discomfort. If stronger pain medications are required, contact a healthcare provider.

Other treatments for cold-related injuries include local wound care for blisters and open sores. Keep the wounds clean and dry and avoid rupturing blisters. Topical aloe vera cream is recommended.

When should I seek medical care for a cold weather-injury?

Chilblains can usually be treated at home, though if signs of infection, blisters or open sores develop, individuals should consult a health care practitioner. Also, those patients with recurrent chilblains may also seek medical care.

Individuals with trench foot or frostbite should consult a health care practitioner. These are more serious cold weather-related injuries and often require admission to the hospital and long-term medical or surgical management. Lastly, if there is blistering or open sores and you are not up to date on your tetanus vaccination (within the last 10 years), you should receive a tetanus booster.

Frostbite Chilblains, and Trench Foot At A Glance:

Cold weather-related injuries occur with and without freezing of body tissues.
The young and the elderly are especially prone to cold weather-related injuries.
Alcohol and illicit drug use increases the risk of cold weather-related injuries.
Examples of cold weather-related injuries include chilblains, "trench foot," and frostbite.
Frostbite can lead to loss of body parts.
It is important not to thaw an extremity if there is a risk of it re-freezing.

Notes:
Dr. Nelson Crumfield

[Watch page ]

EditText of this page (last edited June 10, 2010)