Frostbite
During the winter season with extremely cold temperatures, frostbite becomes a real danger. While initially a problem for soldiers in the military, frostbite now occurs in civilians with prolonged exposure to the elements. Frostbite can occur during work as well as during recreation. Males, ages 30-49, are most commonly affected.
Frostbite occurs when tissue freezes. There can be direct cell injury with intracellular or extracellular crystal formation. More commonly a vascular insult or ischemia occurs. During very cold temperatures, blood vessels to the extremities constrict, sending more blood to the heart and brain. This leads to frostbite injury occurring most commonly in the tip of the nose, ears, finger and toes.
The severity of the frostbite is directly related to the duration of exposure to below freezing temperatures and wind chill. Frostbite can occur in as few as 10 minutes, if skin is exposed to temperatures less than 20 degrees Celsius, in the face of 40 mile per hour winds.
Risk factors for frostbite include:
- Intoxication
- Dehydration
- Wind exposure
- Underlying vascular disease
- Smoking
- Fatigue
Classification of frostbite:
1st Degree: Superficial skin injury with erythema, edema, and hyperemia
2nd Degree: Full thickness skin injury with erythema and blistering
3rd Degree: Full thickness skin and subcutaneous injury with edema and bluish discoloration
4th Degree: Full skin necrosis, with necrosis to even deeper structures
Symptoms of frostbite are related to the depth of injury.
Superficial frostbite causes numbness, tingling and a cold sensation. The patient may complain of a whitish, pale digit.
Deeper damage can lead to decreased sensation followed by a loss of sensation. Swelling, blood filled blisters and eventually a purplish blue waxy appearance can occur if damage is severe enough.
Treatment
- Get inside to a warm room and remove all wet clothes immediately.
- Immerse the hand or foot in warm water for 30-45 minutes in water at 40-42 degrees Celsius. If the water is too warm the treatment can be painful.
- Avoid dry heat, as this can burn skin. For example avoid use of a heating pad, sun lamp or radiators.
- After rewarming, elevate the extremity and dress the wound with antibiotic ointment such as Silvadene.
- No systemic antibiotics are indicated in most cases.
- Blisters are not debrided unless they have ruptured.
- Begin range of motion exercises if motion is noted to be limited. Hand therapy can also be helpful to decrease edema and sensitivity.
- No surgery should be performed for at least 2 months to allow tissue to demarcate. Occasionally, excision of necrotic tissue with either direct closure or flap closure is required. Infrequently, release of joint or intrinsic muscle contractures is needed
Long term consequences of frostbite injury include persistent burning or tingling pain, sweating, ulceration and cold sensitivity.
Prevention
- Avoid prolonged exposure to extremely cold and windy days
- Wear warm clothing. The outside layer should block the wind as wind chill can lower the skin temperature.
- Deeper layers should provide wicking to keep skin dry.
- Wear a hat to prevent heat loss.
If there is any doubt about the care and treatment of frostbite digits, do not hesitate to refer to the appropriate specialist. Hand surgeons and plastic surgeons see these injuries frequently in the winter. They can best provide local wound care, surgery if needed and guide hand therapy when appropriate.
Information provided by: Hand & Plastic Surgery Associates, Ltd. – The physicians of HPSA treat the most challenging and complicated hand and wrist problems as well as minor conditions and injuries. They believe that seeing a physician who specializes in surgery of the hand yields the best results. When caring for injured workers, HPSA takes a proactive role to insure that these individuals are returned to work as soon as medically possible. They assist employers and case managers in determining appropriate job placement. Their physicians are also available for independent medical evaluations and second opinions. Visit their website at www.handplastic.com to learn more about HPSA.
