Symptoms
In localized frostbite, the skin becomes pale, cold, hard, and insensitive to touch and pain. Only when it warms and thaws does redness appear and severe, pulsating pain, burning, and tingling set in. In addition, edema and blisters may form and, in a severe course, tissue dies. Often affected are exposed parts of the body, such as the face, ears, nose, and hands and feet. Like burns, frostbite can be classified into different degrees of severity. The classification according to the depth and type of blisters (clear or bloody) is also common today. It can only be made after thawing, as frostbite looks similar beforehand. Superficial:
- 1st degree: redness, hyperemia and swelling, no blisters or necrosis.
- 2nd degree: severe oedema, hyperemia, blistering (clear fluid).
Deep:
- 3rd degree: subcutaneous frostbite, purple-bloody blisters, skin necrosis, blue-gray discoloration.
- 4th degree: The tissues, muscles, tendons and bones freeze, low oedema, deep red, later dry to black discoloration, tissue loss.
Complications
Complications can range from mild to severe. Pain and sensory disturbances such as throbbing, tingling, electric shocks, or increased sensitivity to cold can persist for weeks to years. Frostbite can cause severe skin and tissue damage that may require amputation of entire limbs.
Causes
Localized frostbite is not just hypothermia; the tissue actually freezes; ice crystals form. On the one hand, cold leads to an undersupply of blood and oxygen to the tissue (hypoxia, ischemia) because of vasoconstriction. Blood circulation is additionally impeded by clots. Second, extracellular water crystallizes, causing an osmotic imbalance, dehydrating and damaging cells and leading to cell death. Ice crystals also mechanically damage cells.
Risk factors
- Low temperatures, wind, humidity, water
- Too light clothing in cold environment
- Occupation, for example, military service
- Leisure activities such as skiing, mountaineering, hiking.
- Middle age (recreational activities).
- Homelessness
- Mental impairment, for example, due to alcohol use, intoxicants, medications, trauma, dementia, or mental illness. Alcohol additionally dilates the vessels and inhibits shivering, leading to heat loss.
- Accidents, such as a car accident or an avalanche accident.
- Vascular diseases, circulatory disorders, neuropathy.
- Tight clothing
- Smoking: Nicotine
- Medication: vasoconstrictors, beta-blockers.
Diagnosis and differential diagnoses
Frostbite is not frostbite, but an inflammatory skin reaction to cold temperatures and a humid climate (see there). Conditions that cause skin blisters can be confused with frostbite, such as burns, insect bites, herpes simplex, impetigo, or pemphigus vulgaris.
Prevention
- Clothing adapted to environmental conditions, protection from cold, wind and water.
- Stay dry
- Do not cut off the extremities with too tight clothes
- Eat and drink enough, avoid dehydration
Whether anhydrous ointments, as traditionally used in Finland, help protect against cold is controversial. It is possible that, on the contrary, they may even be a risk factor for frostbite.
Treatment
If frostbite is suspected, patients should seek medical attention as soon as possible when out of the cold. In general, frostbite should be thawed as soon as possible. It must be ensured that once thawed tissue does not freeze again later, otherwise it will die (!) Wet and cold clothing should be changed. The frozen areas should not be rubbed – as was recommended in the past – otherwise the tissue damage will worsen. In medical treatment, frozen tissue is quickly thawed with warm water (37-42°C) with the addition of disinfectants such as octenidine. Antibiotics are used to treat infections, and analgesics such as opioids are used to treat the severe pain.Non-steroidal anti-inflammatory drugs such as ibuprofen are anti-inflammatory. In addition, other drugs such as antithrombotics, vasodilators and vaccinations (tetanus) are used; for the exact procedure, please refer to the specialist literature. Wounds are professionally dressed and debridement may be performed. If medical help is not available in an emergency, the tissue can also be thawed by oneself, for example by holding it under the armpits of another person or as in medical treatment with a warm water bath. No direct and hot heat source should be used (e.g. hairdryer, fire), as this heats the skin too much and causes burns. It is normal to experience local swelling, redness and possible blistering during and after thawing. Rings, tight clothes and shoes should therefore be removed before thawing. Elevation of the limb reduces oedema formation. For analgesia, take sufficiently high doses of analgesics such as ibuprofen or another NSAID.
