Cold injury | |
---|---|
Other names | Cold weather injury |
Frostbitten fingers after descent from mountain climbing | |
Symptoms | Numbness, skin discoloration, blisters, swelling, cold sensation[1][2] |
Complications | Necrosis, gangrene, chronic pain, amputation[3][4] |
Types | Freezing, nonfreezing[5] |
Causes | Exposure to cold temperatures[6] |
Risk factors | Military occupation, recreational winter activities, homelessness, inadequate or wet clothing, substance abuse, diabetes, peripheral vascular disease[6][7] |
Diagnostic method | Based on symptoms[1][6] |
Differential diagnosis | Hypothermia, Raynaud's phenomenon, chilblains (pernio), cold urticaria[8][9] |
Prevention | Minimize cold exposure, wear protective clothing, change wet clothing, avoid substance use, maintain appropriate nutrition[1][4] |
Treatment | Move to warm and dry environment, rewarming, medication, wound care, surgery[4][10] |
Cold injury (or cold weather injury) is damage to the body from cold exposure, including hypothermia and several skin injuries.[6] Cold-related skin injuries are categorized into freezing and nonfreezing cold injuries.[5] Freezing cold injuries involve tissue damage when exposed to temperatures below freezing (less than 0 degrees Celsius).[6][7] Nonfreezing cold injuries involve tissue damage when exposed to temperatures often between 0-15 degrees Celsius for extended periods of time.[6] While these injuries have disproportionally affected military members, recreational winter activities have also increased the risk and incidence within civilian populations.[6] Additional risk factors include homelessness, inadequate or wet clothing, alcohol abuse or tobacco abuse, and pre-existing medical conditions that impair blood flow.[6][7]
Freezing cold skin injuries include frostbite and frostnip.[8] These injuries often affect the fingers, toes, nose, and ears since they are less commonly covered by clothing when in cold environments.[1] Affected skin becomes numb, turns white or blue, and develops blisters.[1] Frostnip is a superficial skin injury that won't freeze the skin or cause long-term damage.[8] Frostbite involves freezing of fluids inside and outside of cells that results in cell breakdown, electrolyte imbalances, and inflammation.[8] Surrounding blood vessel constriction and injury disrupts blood flow to affected tissue, which may cause tissue death (necrosis).[11] Diagnosis is based on symptoms, but imaging can help assess viable tissue and risk of amputation.[6] Pre-hospital treatment involves transfer to a warm environment, changing wet clothing, and rapid rewarming with warm water if refreezing is not expected.[11] Hospital management involves rewarming, wound care, and medications to treat pain and possible blood clots.[11] Amputation of unsalvageable tissue may be required weeks to months after initial injury.[11]
Nonfreezing cold skin injuries include trench foot, a subclass of immersion foot caused by exposure to cold temperatures.[2] These injuries often affect the feet after being subjected to wet cold for several hours or days.[4] Affected individuals report a tingling or numbing sensation, red or blue discoloration, and swelling or blisters in affected skin.[2] The mechanism of injury isn't fully understood, but may involve cold-induced damage to blood vessels and nerves that results in small blood vessel (capillary) destruction, swelling, and tissue necrosis.[5] Diagnosis is based on symptoms.[2] Pre-hospital treatment includes transfer to a warm environment and exchanging wet clothing.[4] Hospital management includes gradual rewarming with air drying, elevating affected skin, and pain management.[4]