Frostbite is a thermal tissue injury caused when tissue is exposed to sub-zero temperatures (in degrees Celsius) long enough for ice crystals to form in the affected tissue. (1,2,3)
- the term frostbite may cover a wide spectrum of injuries, from minimal tissue damage to substantial tissue necrosis with amputation
- severity of frostbite injury is proportional to the temperature, duration of exposure, and amount and depth of frozen tissue
Historically the condition was seen in military work in the field
- however in the in the past 20 years the number of civilian cases has increased
- those who partake in winter sports such as skiing, hiking, mountain and ice climbing
- it is also common in the elderly or the homeless during cold spells and individuals in which behavioural and physiological compensation can be left wanting
- in addition, industrial injury and malfunctioning or misuse of equipment using NO or CO2 have also been described
- its likelihood is increased if accompanied by wind or high altitude, as encountered by climbers and explorers
Frostbites are commonly seen in hand and feet which accounts for 90% of cases. In addition they may also affect the face (nose, chin, earlobes, cheeks and lips), buttocks/perineum (from sitting on metal seats) and penis (joggers and Nordic skiers).
Clinical features:
- loss of sensation and a pale, waxy, bluish skin discolouration (cyanosis)
- blisters and oedema may be present in the affected areas
- favourable clinical finings include
- clear fluid in the blisters, retained sensation and normal skin colour
- poor prognostic signs include cloudy or haemorrhagic (bloody) fluid in the blisters, cyanosis, lack of oedema and firm skin in the frostbitten area
Click here for an example image of this condition
Risk factors for the development of frostbite other than temperature include:
- physical immersion in water
- wind-chill
- fatigue
- malnutrition
- smoking
- alcohol and substance abuse
- medical comorbidities including peripheral vascular disease, diabetes, neuropathies, dementia and mental illness
Frostnip
- a precursor to frostbite that presents with symptoms similar to grade 1 frostbite
- fully reversible and holds no long-term effects
Reference:
- McIntosh SE, Freer L, Grissom CK, et al. Wilderness Medical Society clinical practice guidelines for the prevention and treatment of frostbite: 2024 update. Wilderness Environ Med. 2024 Jun;35(2):183-97.
- Sheridan RL, Goverman JM, Walker TG. Diagnosis and treatment of frostbite. N Engl J Med. 2022 Jun 9;386(23):2213-20.
- Imray CH, Oakley EH. Cold still kills: cold-related illnesses in military practice freezing and non-freezing cold injury. J R Army Med Corps. 2005 Dec;151(4):218-22.