Frostbite
Frostbite is a skin injury that occurs when exposed to extreme low temperatures, causing the freezing of the skin or other tissues,[1] commonly affecting the fingers, toes, nose, ears, cheeks and chin areas.[6] Most often, frostbite occurs in the hands and feet.[7][8] 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] Complications may include hypothermia or compartment syndrome.[2][1]
| Frostbite | |
|---|---|
| Other names | Frostnip |
 | |
| Frostbitten toes two to three days after mountain climbing | |
| Specialty | Dermatology, emergency medicine, orthopedics |
| Symptoms | Numbness, feeling cold, clumsiness, 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] |
| Frequency | Unknown[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 by wearing proper, fully-covering clothing, maintaining hydration and nutrition, avoiding low temperatures, and minimizing strenuous physical activity while maintaining a sufficient core temperature.[2] Treatment is by gradual rewarming, generally from cold to warm water, and should only be done when consistent temperature can be maintained and refreezing is not a concern.[2][1] Rapid heating or cooling should be avoided since it could potentially cause heart stress or cause burning.[9] Rubbing or applying force to the affected areas should be avoided as it may cause further damage such as abrasions.[2] The use of ibuprofen and tetanus toxoid is recommended for pain relief or to reduce swelling or inflammation.[1] For severe injuries, iloprost or thrombolytics may be used.[1] Surgery is sometimes necessary.[1] Amputation should be considered a few months after exposure in order to consider whether the extent of injury is permanent damage and thus necessitates drastic treatment.[2]
Evidence of frostbite occurring in people dates back 5,000 years.[1] Evidence was documented in a pre-Columbian mummy discovered in the Andes.[7] The number of cases of frostbite is unknown.[5] 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] 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]