Diseases

Cold Injury (Frostbite) Information

Chilblains signs and symptoms

Chilblains (also known as pernio) are a common type of cold weather-related injury that can develop in predisposed individuals after exposure to nonfreezing temperatures and humid conditions. Chilblains typically develop because of an abnormal vascular response several hours after the area exposed to cold is re-warmed.Chilblains are itchy, painful, reddish, or purplish areas of swelling that usually affect the fingers, toes, nose, or ears. In some individuals, blisters or small open sores may form, increasing the risk for developing an infection. 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 chilblains to recur in susceptible individuals.

First aid treatment for frostbite, frostnip, trench foot, and chilblains

The initial treatment for any cold weather-related injury involves removing yourself or others from the precipitating cold environment, if possible, to prevent further heat loss.

• Move indoors, and remove all wet clothing and constricting clothing (such as socks, boots, and gloves), and replace with dry clothing.
• Avoid massaging or rubbing the affected area, as this will only aggravate the injury.

• Gradually rewarm the affected area, and treatment can generally be accomplished at home.
• Some individuals may benefit from various lotions, while others may require treatment with corticosteroid creams.
• If open sores develop, they should remain clean and be monitored for signs of infection.

• Frostnip will generally improve with conservative rewarming measures at home.
• Frostnip to the hands, for example, can be treated by breathing into cupped hands or placing the hands in the armpit area.
• Alternatively, the affected area can be submerged in warm water until normal sensation is restored.

• Individuals with trench foot should have their wet shoes and socks removed,and the feet should be elevated, cleaned and air dried.
• Depending on the severity of the condition, some individuals may require antibiotics and/or surgical management of infection or wet gangrene (tissue destruction by bacterial infection, usually Clostridium spp).

• Frostbite requires immediate medical attention. Ideally, treatment should be instituted in a health-care facility, when possible.
• Prior to transport to a health-care facility, if possible, loosely wrap the affected area in a dry sterile bandage or a clean blanket to prevent further trauma. Cotton may be placed between the toes or fingers, if affected, to prevent any potential damaging effects of rubbing against one another.
• The most effective treatment measure for frostbite is rapid rewarming. This is accomplished by immersing the affected area into a circulating tub of warmed water that is between 40 to 42 C (104 to 108 F) for 20 to 40 minutes or until thawing is complete. Warm wet packs at the same temperature may be used if a tub is not available.
  • It is important NOT to rapidly rewarm and thaw the affected area if there is a risk that it may refreeze. This leads to more severe tissue damage and must be avoided.
  • During the rewarming process, the pain may be extreme and oral or intravenous analgesics may be required.
• After rapid rewarming is complete, the affected area should be dressed and splinted. Further treatment will focus on wound care, pain control, and providing a tetanus vaccine booster shot, if needed.
• Surgical consultation may be obtained for managing wound care, as well as for the longer-term sequelae of serious frostbite injuries that my require amputation of gangrenous tissue.

Frostbite and cold weather-related injuries definitions and facts

• Cold weather-related injuries occur with and without freezing of body tissues.
• Cold weather-related injuries include chilblains, trench foot, frostnip, and frostbite.
• Signs and symptoms may include
  • tingling,
  • numbness, and
  • changes in the color and texture of the skin.
• Treatment generally includes moving out of the cold environment, removing wet clothing, and rewarming the affected area.
• Frostbite is a serious cold weather-related injury that requires immediate medical attention and rapid rewarming. Do not thaw the affected area if there is the risk of refreezing.
• Certain individuals, such as the elderly, children, alcoholics, and the homeless, are at increased risk of developing cold weather-related injuries.
• Prevention of cold weather-related injuries is best accomplished through proper planning and preparation for cold weather.

Frostnip signs and symptoms

Frostnip is a mild cold weather-related injury that typically affects the face, ears, toes, and fingers.Symptoms of frostnip usually occur after exposure to cold weather. The affected area(s) may:

• appear pale,
• be accompanied by burning, itching or pain;
• tingle
• feel numb

Superficial and severe frostbite stages

Frostbite occurs when there is freezing of body tissue, and it is the most serious of the cold weather-related injuries. Frostbite usually affects the hands, feet, nose, ears, and cheeks, though other areas 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, which ultimately leads to cell death. Upon rewarming of the affected tissue, vascular damage and complex cellular metabolic abnormalities lead to tissue death.Damage to tissue is most pronounced when there is prolonged cold weather exposure, the affected area slowly freezes, and the subsequent rewarming process is slow. Repeated thawing and refreezing of the affected tissue is particularly damaging, and should always be avoided.Frostbite injuries can be classified as either superficial or deep, depending on the tissue depth of injury.

• Superficial frostbite injuries involve the skin and subcutaneous tissues.
• Deep frostbite injuries extend beyond the subcutaneous tissues and involve the tendons, muscles, nerves, and even bone.

Trench foot signs and symptoms

Trench foot also referred to as immersion foot was named after the condition suffered by many soldiers in the trenches during World War I, though it is a condition still encountered today, often in homeless individuals. Trench foot develops after a prolonged exposure to a wet, cold, environment and is typically a more serious condition than chilblains. Tight-fitting, constricting boots and footwear serve to exacerbate the condition. Trench foot does not require freezing temperatures, and can occur with temperatures of up to 60 F (15.5 C).The symptoms of trench foot may include:

• pain,
• itching,
• numbness, and
• swelling.

When to seek medical care for frosbite or frostnip

• Chilblains can generally be treated at home, though if signs of infection develop from an open sore, individuals should consult a health-care professional. Patients with recurrent chilblains should also seek medical care, as there may be another underlying disease process leading to this condition.
• Frostnip can be managed at home, and this condition does not typically require further evaluation.
• Individuals with trench foot should generally consult a health-care professional to assess the degree of injury and to monitor for any signs of infection or gangrene.
• Individuals with frostbite or suspected frostbite should immediately go to an emergency room. Furthermore, these individuals may also be suffering from hypothermia, which requires additional treatment and evaluation, and may constitute a life-threatening condition. These are serious cold weather-related injuries that may require admission to a hospital.