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Overview |
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Definition |
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Frostbite is a cold injury that results from exposure to below-freezing
temperatures for several hours and usually affects the extremities, nose,
cheeks, and ears; male genitalia may be affected as well. Frostbite can occur
with above-freezing temperatures if there is a strong wind, high altitude, or
extreme wetness. Superficial frostbite is characterized by injury to the skin
and subcutaneous tissues that resolves within 3 to 4 weeks. Deep frostbite
involves muscle, nerves, and blood vessels and may result in tissue necrosis and
gangrene. Historically, frostbite has been a problem among military personnel
and high-altitude climbers, but anyone exposed to extreme cold for a long period
of time (e.g., homeless individuals or those sitting in a broken-down car) may
develop frostbite. |
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Etiology |
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The physiologic response to cold is to preserve the core (internal)
temperature. One way in which this is accomplished is through peripheral
vasoconstriction and shunting, thereby preventing hypothermia (a generalized
lowering of body temperature below 93 degrees Fahrenheit (34 degrees Celsius).
This, in turn, prevents adequate blood flow and heat to the extremities.
Extremity heat is initially preserved by alternating cycles of cold-induced
vasoconstriction and vasodilatation (hunting response); this response fails
under extremely cold conditions as the preservation of internal body temperature
takes precedence over the extremities. |
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Risk Factors |
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- Intoxication with alcohol or other substances
- Extremes of age
- Cardiovascular disease
- Peripheral vascular disease
- Diabetes mellitus
- Psychiatric illness
- Exhaustion, hunger, malnutrition, or dehydration
- Winter sports, especially at high altitudes
- Outdoor occupations
- Homelessness
- Trauma
- Smoking
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Signs and Symptoms |
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- Pain progressing to numbness
- White color and waxy appearance of the skin of effected body part (the
result of vasoconstriction)
- Hyperemia (blood engorgement) of the body part after rewarming
- Burning sensation and edema that may last for weeks
- Vesicles and bullae may develop
- Black eschar may develop several weeks into the course of
frostbite
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Differential
Diagnosis |
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Exposure history and physical examination generally lead to rapid,
unequivocal diagnosis. |
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Diagnosis |
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Physical Examination |
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A history detailing the temperature and duration of exposure is essential as
the extent of cellular damage depends on the length of time the tissue is
frozen. Frostbitten areas are initially cold, hard, white, and numb. Warming
produces blotchy red areas, edema, and pain. A superficial injury is suggested
by soft, pliable subcutaneous tissue. A deep injury is suggested by a violet
discoloration after rewarming, hemorrhagic blisters, and lack of
edema. |
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Pathology/Pathophysiology |
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When tissue temperatures drop below 50 degrees Fahrenheit (10 degrees
Celsius), numbness occurs, accompanied by vasoconstriction and leakage of plasma
into the interstitium. At 32 degrees Fahrenheit (0 degrees Celsius) or less, ice
crystals form, usually in the extracellular space but also intracellularly. This
results in water exiting from cells; cell death occurs via dehydration when
one-third of its volume is lost. Thawing or rewarming may lead to red cell
sludging, microthrombi, and hypoxemic vasospasm, affecting the microcirculation
and leading to tissue ischemia and necrosis.
Four levels of frostbite injury include: (1) first-degree: redness and edema
for several days; (2) second-degree: blisters and bullae formation within 48
hours that heal over several weeks, leaving an eschar; (3) third-degree: severe
edema, hemorrhagic vesicles, and ischemic necrosis; and (4) fourth-degree: dry
gangrene. |
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Laboratory Tests |
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- Serum electrolytes and arterial blood
gases—to monitor acid base status and electrolyte
shifts, especially during rewarming and rehydration
- Blood and wound Gram's stains and cultures—to
monitor secondary infection and sepsis
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Imaging |
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- Traditional and magnetic resonance
angiography—to assess peripheral circulation and
demarcation of ischemic tissue
- Roentgenograms—to identify osteoarthritic
changes months after injury
- Technetium (Tc)-99 bone scans—to determine
tissue perfusion and viability
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Other Diagnostic
Procedures |
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- Microwave thermography
- Doppler ultrasound and digital
plethysmography—to assess vascular patency and
determine suitability for medical
sympathectomy
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Treatment Options |
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Treatment Strategy |
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Mild frostbite is treated with rapid rewarming, daily whirlpool baths, and
bed rest. The injured area should be washed with an antiseptic agent and a
sterile dressing applied. Deep frostbite is treated by rapid thawing (only if
there is no danger of refreezing) in a water bath of 104 to 108 degrees
Fahrenheit (40 to 42 degrees Celsius) for 15 to 30 minutes; the patient should
be hospitalized and the frostbitten extremity elevated. Narcotics are often
necessary for pain. Prevention and early treatment of infection are critical.
Cotton wool should be used to separate affected toes or fingers to prevent
tissue maceration. Twice daily water (whirlpool) baths with an aseptic solution
at 95 to 98.6 degrees Fahrenheit (35 to 37 degrees Celsius) are continued until
healing has occurred (weeks to months). Deep frostbite is often accompanied by
hypothermia. This is a medical emergency requiring rewarming in a hospital
setting because hypoxemia and acid-base and electrolyte disturbances, which
accompany rewarming, may lead to fatal ventricular arrhythmias.
Never rub or massage frozen body parts and avoid walking on a frostbitten
foot if possible. Use warm, not hot, compresses as patient may be unable to
detect temperatures high enough to cause burns. Remove any rings, watches, or
bracelets to prepare for the swelling that occurs during
rewarming. |
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Drug Therapies |
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- Opioid analgesics—to treat pain during
rewarming
- Ibuprofen (and other NSAIDs)—to treat pain
and inflammation during healing
- Tetanus toxoid—to update immunization and
prevent tetanus
- Topical antibacterials (providone-iodine)—to
prevent infection
- Broad-spectrum antibiotics—to prevent or
treat bacterial infections
- Reserpine and guanethidine—to institute a
medical sympathectomy; the efficacy of these meds for this purpose, though, is
not established
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Surgical Procedures |
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Initially frostbite looks worse than it is because the skin may be more
seriously affected than the subcutaneous tissues; thus, the decision to amputate
should be delayed until necrotic demarcation occurs; this process may take
several months. However, surgery should not be delayed in patients with
refractory pain; sepsis; or wet, infected gangrene.
- Amputation—to treat gangrene or
sepsis
- Sympathectomy—to decrease severe edema,
increase tissue salvage, and alleviate sequelae; long-term benefits have not
been proven
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Complementary and Alternative
Therapies |
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As described earlier, frostbite warrants immediate medical attention with
conventional therapies to help salvage and protect viable tissue in affected
areas. Nutritional support may enhance conventional medical therapy (Purkayastha
et al. 1993). General advice for the prevention of hypothermia (which may lead
to frostbite, see section entitled Etiology) includes maintenance of
adequate hydration and caloric intake prior to and during cold exposure to
preserve core temperature. |
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Nutrition |
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Vitamin C:
A controlled animal study of 150 albino rats evaluated the therapeutic role
of vitamin C and Indian black tea following frostbite. Rats were randomly
assigned to one of six groups. Oral vitamin C plus rapid rewarming in a warm
water bath, and rapid rewarming in the tea decoction alone, showed greater
preservation of tissue compared to controls (P<0.05). Rapid rewarming in a
tea decoction plus oral vitamin C showed the greatest preservation of tissue
(P<0.01). Comparatively, this group also experienced the smallest number of
severe injuries (Purkayastha et al. 1993).
Research is necessary to assess the efficacy of both vitamin C and black tea
for treatment of frostbite in humans. The association of reduced tissue necrosis
with rapid rewarming in Indian black tea decoction demonstrated in the rats may
be partly related to the constituents of tea, but the exact mechanism is not
known. The contents of the tea that may have been responsible for the positive
clinical results include:
- Quercetin – may reduce capillary fragility;
free radical scavenger
- Caffeine – may relax smooth muscle and act as
a nerve stimulant
- Theophylline – may enhance
thermogenesis
Improved outcomes for the groups administered vitamin C may be due to the
following:
- Favorable alterations in metabolic and circulatory function
- Enhancement of wound healing
- Potentiation of cellular immunity, thereby reducing
infection
- Free radical scavanging (Purkayastha et al. 1993).
Vitamin E:
A review of free radical generation during rewarming and reperfusion of
frozen tissues suggests that antioxidant therapy, especially with lipid-soluble
antioxidants (e.g., vitamin E), may be protective against cold-induced injuries
(Bhaumik et al. 1995). |
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Herbs |
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- Poplar buds (Populus spp. including P. nigra, P.
Canadensis, and P. tachamahaca), also known as balm of Gilead and
balm of Mecca, are approved by the Commission E for external use in the case of
frostbite. Poplar buds, which contain essential oils, flavonoids (including
quercetin), and phenol glycosides (including caffeic acid and fatty acids), have
antimicrobial and analgesic properties. Semi-solid ointment or other topical
preparation containing 20% to 30% of bud exudate is applied to affected
frostbitten area (Blumenthal et al. 2000).
- Cayenne Pepper (Capsicuum spp.) in topical form has been
used traditionally in China and Japan to treat frostbite (Blumenthal et al.
2000).
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Homeopathy |
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Formal scientific studies evaluating homeopathic remedies have not been
documented to date for prevention or treatment of frostbite. However,
experienced homeopaths, after considering a patient's constitution, have used
the following remedies in the clinical circumstances described:
- Arsenicum album—For coldness of the
extremities with black discoloration of the nails. Patients for whom this is
appropriate are typically restless and very anxious.
- Hepar—For intolerance of cold and
intense sensitivity to pain, particularly when the head and ears are exquisitely
sensitive to wind and cold. The patients for whom this is appropriate tend to
complain of splinter-like pain or of abscesses that are slow to
heal.
- Veratrum album—For weakness and
collapse with a sensation of internal coldness that is described as ice water in
the veins; also used for the patient suffering from cold hands, feet, and face
accompanied by headache.
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Massage |
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Massage is contraindicated in the case of frostbite.
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Patient Monitoring |
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Because the extent of frostbite is not usually evident on clinical
presentation, monitoring over weeks to months is essential to determine the
depth of injury. |
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Other
Considerations |
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Prevention |
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- Several layers of warm clothing, especially protection from wind and
water, that do not constrict movement
- Dry, warm gloves, socks, and insulated boots
- Head covering, preferably with ear flaps in extreme conditions, as 30%
of heat loss occurs from the head
- Consuming fluids and food before and during lengthy outdoor
excursions
- Attention to white areas on face and ears of companions who might be
unaware of impending frostbite
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Complications/Sequelae |
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- Increased cold sensitivity in the affected area following
recovery
- Changed skin color
- Faulty nail growth
- Hyperhidrosis
- Pain with use of affected extremity post-recovery
- Loss or alteration of sensation
- Frostbite arthritis
- Squamous and epidermoid cell
carcinomas
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Prognosis |
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Prognosis is entirely dependent on the extent of tissue injury, ranging from
complete recovery with no sequelae to amputation.
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References |
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Barker JR, Haws MJ, Brown RE. Magnetic resonance imaging of severe frostbite
injuries. Ann Plast Surg. 1997;38(3):275-279.
Beers MH, Berkow R. Merck Manual of Diagnosis and Therapy. 17th ed.
Whitehouse Station, NJ: Merck Research Laboratories; 1999:2450-2451.
Bhaumik G, Srivastava KK, Selvamurthy W, Purkayastha SS. The role of free
radicals in cold injuries. Int J Biometeorol. 1995;38(4):171-175.
Blumenthal M, Goldberg A, Brinckmann, J, eds. Herbal Medicine; Expanded
Commision E Monographs. Boston, Mass: Integrative Medicine Communications;
2000:52-56, 311-313.
Carey CG, Schaiff RA. The Washington Manual of Medical Therapeutics.
29th ed. Philadelphia, Pa; 1998:498-499.
Danzel DF. Frostbite. In: Rosen P, et al., eds. Emergency Medicine:
Concepts and Clinical Practice. Vol 1. 4th ed. St. Louis, Mo: Mosby;
1998:953-961.
Goldman L, Bennett JC. Cecil Textbook of Medicine. Vol 1. 21st ed.
Philadelphia, Pa: W.B. Saunders Company; 2000:366.
Laskowski-Jones L. Responding to winter emergencies. Nursing.
2000;30(1):34-39.
Lehmuskallio E, Lindholm H, Koskenvuo K, Sarna S, Friberg O, Viljanen A.
Frostbite of the face and ears: epidemiological study of risk factors in Finnish
conscripts. BMJ. 1995;311(7021):1661-1663.
McAdams TR, Swenson DR, Miller RA. Frostbite: an orthopedic perspective.
Am J Orthop. 1999;28(1):21-26.
Mills WJ Jr. Frostbite: experience with rapid rewarming and ultrasonic
therapy. Part II. 1960. Alaska Med. 1993;35(1):10-18.
Mills WJ Jr. Frostbite and hypothermia: current concepts. 1973. Alaska
Med. 1993:35(1):28.
Mills WJ Jr. Frostbite: a discussion of the problem and a review of the
Alaskan experience. 1973. Alaska Med. 1993;35(1):29-40.
Mills WJ Jr. Summary of treatment of the cold injured patient: frostbite.
1983. Alaska Med. 1993;35(1):61-66.
Mills WJ Jr, Whaley R. Frostbite: experience with rapid rewarming and
ultrasonic therapy: Part I. 1960. Alaska Med. 1993;35(1):6-9.
Mills WJ Jr, Whaley R, Fish W. Frostbite: experience with rapid rewarming and
ultrasonic therapy. Part III. 1961. Alaska Med. 1993;35(1):19-27.
Moschella SL, Hurley HJ. Dermatology. 3rd ed. Philadelphia, Pa: W.B.
Saunders Company; 1994:1855-1856.
Murphy JV, Banwell PE, Roberts AH. Frostbite: pathogenesis and treatment.
J Trauma. 2000;48(1):171-178.
Pinzur MS, Weaver FM. Is urban frostbite a psychiatric disorder?
Orthopedics. 1997;20(1):43-45.
Pulla RJ, Pickard LJ, Carnett TS. Frostbite: an overview with case
presentations. J Foot Ankle Surg. 1994;33(1):53-63.
Purkayastha SS, Chhabra PC, Verma SS, Selvamurthy W. Experimental studies on
the treatment of frostbite in rats. Indian J Med Res.
1993;98:178-184.
Raffle PAB, et al. Hunter's Disease of Occupations. 8th ed. London,
England: Edward Arnold; 1994:310-311.
Reamy BV. Frostbite: review and current concepts. J Am Board Fam Pract.
1998;11(1):34-40.
Schwartz AI, et al. Principles of Surgery. Vol 1. 7th ed. New York,
NY: McGraw-Hill; 1999:983-984.
Urschel JD. Frostbite: predisposing factors and predictors of poor outcome.
J Trauma. 1990;30(3):340-342.
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Copyright © 2000 Integrative Medicine
Communications This publication contains
information relating to general principles
of medical care that should not in any event be construed as specific
instructions for individual patients. The publisher does not accept any
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