Frostbite
Other names	Frostnip
Frostbitten toes two to three days after mountain climbing
Specialty	Emergency medicine, orthopedics
Symptoms	Numbness, feeling cold, clumsy, pale color [1]
Complications	Hypothermia, compartment syndrome [2] [1]
Types	Superficial, deep [2]
Causes	Temperatures below freezing [1]
Risk factors	Alcohol, smoking, mental health problems, certain medications, prior cold injury [1]
Diagnostic method	Based on symptoms [3]
Differential diagnosis	Frostnip, pernio, trench foot [4]
Prevention	Avoid cold, wear proper clothing, maintain hydration and nutrition, stay active without becoming exhausted [2]
Treatment	Rewarming, medication, surgery [2]
Medication	Ibuprofen, tetanus vaccine, iloprost, thrombolytics [1] [5]
Frequency	Unknown [6]

Frostbite occurs when exposure to low temperatures causes freezing of the skin or other tissues. ^[1] The initial symptom is typically numbness. ^[1] This may be followed by clumsiness with a white or bluish color to the skin. ^[1] Swelling or blistering may occur following treatment. ^[1] The hands, feet, and face are most commonly affected. ^[4] Complications may include hypothermia, compartment syndrome, and chronic pain. ^{[2] [1] [5]}

People who are exposed to low temperatures for prolonged periods, such as winter sports enthusiasts, military personnel, and homeless individuals, are at greatest risk. ^{[7] [1]} Other risk factors include drinking alcohol, smoking, mental health problems, certain medications, and prior injuries due to cold. ^[1] The underlying mechanism involves injury from ice crystals and blood clots in small blood vessels following thawing. ^[1] Diagnosis is based on symptoms. ^[3] Severity may be divided into superficial (1st and 2nd degree) or deep (3rd and 4th degree). ^[2] A bone scan or MRI may help in determining the extent of injury. ^[1]

Prevention is through wearing proper clothing, maintaining hydration and nutrition, avoiding low temperatures, and staying active without becoming exhausted. ^[2] Treatment is by rewarming. ^[2] This should be done only when refreezing is not a concern. ^[1] Rubbing or applying snow to the affected part is not recommended. ^[2] The use of ibuprofen and tetanus toxoid is typically recommended. ^[1] For severe injuries iloprost or thrombolytics may be used. ^{[1] [5]} Surgery is sometimes necessary. ^[1] Amputation, however, should generally be delayed for a few months to allow determination of the extent of injury. ^[2]

The number of cases of frostbite is unknown. ^[6] Rates may be as high as 40% a year among those who mountaineer. ^[1] The most common age group affected is those 30 to 50 years old. ^[4] Evidence of frostbite occurring in people dates back 5,000 years. ^[1] Frostbite has also played an important role in a number of military conflicts. ^[1] The first formal description of the condition was in 1813 by Dominique Jean Larrey, a physician in Napoleon's army, during its invasion of Russia. ^[1]

References