Thursday, April 17, 2014

Definition

Frostbite is the temporary (superficial) or permanent (deep) skin tissue damage caused by prolonged skin-tissue temperature of 23 degrees F and below.

Description

Frostbite is the freezing of skin and damage to underlying blood vessels upon exposure to extreme cold.

Blood flow halts in frostbitten skin, and the area must be thawed and rewarmed swiftly to prevent tissue death (gangrene) and infection. The ears, nose, hands, and feet are particularly susceptible.

Frostbite is sometimes accompanied by a life-threatening drop in internal body temperature, known as hypothermia, which must be treated first.

Frostbite is not a common problem, but can be a big problem for people who do not regularly experience severe cold weather, as well as for people who do winter camping, high-altitude climbing, hunting, and snowmobiling.

Frostnip, a superficial freezing of the outer layer of the skin - also can occur if you are exposed to cold weather. The skin turns white as blood circulation decreases, then stings, and becomes quite painful.

Frostnip can occur during vigorous outdoor activity and you may not be aware of it until you stop exercising.

Causes

Exposure to extremely cold temperatures (32 degrees or below) for prolonged periods of time causes frostbite. The risk becomes greater as the temperature drops and the wind increases.

The risk of frostbite increases with impaired circulation. Those with peripheral vascular disease or diabetes mellitus and those taking beta-blocker drugs are more vulnerable.

Symptoms

Common warning signs include a progressive numbness and a loss of sensitivity to touch. The affected area will also tingle or feel as if it is burning. As the condition worsens, the pain begins to fade or eventually disappear.

The skin also changes color when exposed to extreme cold. It blanches, then may appear red, and finally white-purple if allowed to freeze.

Most people say the affected part of the body feels "wooden," and it may appear to have a wooden texture.

Frostbite can affect any part of the body, but the tip of the nose, ear lobes and rim, fingertips, and toes are the most likely areas.

In mild cases, full recovery can be expected with early treatment. Severe cases of frostbite can result in infection, or gangrene - the death of some body tissue due to the lack of blood supply.

Treatment

When you first notice signs of frostbite, come out of the cold immediately and rewarm the affected area as rapidly as possible.

Do not rub the skin in an effort to get blood flowing back to the area. This causes friction and will destroy the already damaged skin and underlying tissue, as well as increase the risk of infection.

To thaw frostbitten skin, immerse the affected part in a bath kept at a constant temperature of 104 to 105 degrees F for an hour or more. This will cause the blood vessels to dilate and circulation to return to the area.

Rapid rewarming is an intensely painful procedure. Take two ibuprofen, aspirin, or acetaminophen to dull the pain.

Do not smoke or chew tobacco. Nicotine constricts the blood vessels, reduces blood flow to chilled areas, and delays the healing process. If you do not have access to warm water, stick the frozen body part under an armpit or between the thighs.

When the skin has thawed and rewarming is complete, cover the damaged skin with bandages and warm clothing. Contact your doctor or go to an emergency room.

If there is any chance of refreezing a thawed body part, do not rewarm it in the first place. Freezing, rewarming and freezing the skin again causes much more tissue damage than being frozen once. As it rethaws, the skin turns red, swelling develops, and the area becomes quite painful. Dark blisters appear on the skin and continue to form over the ensuing week(s) as new skin develops.

Questions

Is it frostbite?

Is there any permanent damage?

What treatment is necessary?

Prevention

Before going outside in extremely cold temperature, apply skin moisturizer to the face, hands, and any other body part that may be exposed to the cold. Dress warmly, wear dry clothing, and stay out of the wind. Wear a face mask for extra protection. Wear heavy mittens instead of gloves in freezing cold weather. When the fingers are together in a mitten, their collective body heat keeps the hand warm.

Children playing outside should be watched carefully to make sure that they do not lose or remove mittens or head-coverings.

Be extremely careful when pumping gas into your car if the temperature is below freezing. Gasoline on exposed skin evaporates very quickly, lowers the temperature of the skin, and makes it more susceptible to frostbite.

When you exercise in below-freezing temperatures, wear layers of clothing. The more layers you wear, the better insulated you are. The innermost garment must be nonabsorbent and loosely woven.

Go inside, if possible, when you feel too cold. Remember that fatigue, lack of oxygen in high elevations, and consumption of alcohol may cause you to disregard discomfort and cold.

Avoid smoking or drinking before venturing out into extreme cold. Tobacco decreases circulation by constricting blood vessels, and alcohol interferes with the body's ability to regulate temperature.