Frostbite severity is determined by the depth of the freezing and subsequent injury. Grading scales are sometimes used to guide therapy.
Diagnosis is clinical, but technetium-99m or magnetic resonance scanning can give an early indication of prognosis.
The mainstay of treatment is rapid initial rewarming of the injured tissue.
Being a thermal injury, wound management is similar to the management of burns and involves debridement of white blisters, regular aloe vera application, and regular hydrotherapy. Early therapy with a non-steroidal anti-inflammatory drug is advised.
Emerging data suggest thrombolytic therapy may be of benefit in severe frostbite if given within 24 hours of injury. It is best given within 6 hours of injury.
It takes 1 to 3 months to determine the viability of the injured tissue and surgery should normally be delayed.
Risk factors for amputation include severe injury grades, late presentation, lower extremity involvement, and wound infection.
Frostbite is an injury produced by tissue freezing following exposure to cold. Frostbite requires temperatures of 0°C (32°F) or colder to occur.
History and exam
Key diagnostic factors
- presence of risk factors
- cold or numbness of affected extremity
- pain during rewarming
- purplish skin discoloration
- white or yellow skin plaque
- superficial skin vesiculation
- deep purple blisters
- tissue necrosis and mummification (dry gangrene)
Other diagnostic factors
- joint dislocation
- cold exposure
- previous frostbite
- vascular insufficiency
- high altitude
- extremity trauma
- constrictive clothing or equipment
1st investigations to order
- clinical diagnosis
Investigations to consider
- technetium-99m pertechnetate scintigraphy
- magnetic resonance angiogram of affected extremity
- plain radiography
- thermography and duplex imaging
- Cutaneous burns
- Raynaud's phenomenon
- Heat illness and cold injury: medical management part 2 guidance
- Wilderness Medical Society clinical practice guidelines for the prevention and treatment of frostbite: 2019 update
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