It’s important to keep in mind that cold-related injury can occur in just about any month of the year depending on the conditions, January - March is the most critical time to be vigilant. In the spirit of a healthy and safe winter season, let us review two common conditions: “frostbite” and the less familiar “frostnip”.
What is frostnip and how does it differ from frostbite?
Frostnip is a mild cold-induced condition consisting of pallor of the affected area with associated tingling or mild pain. The key with frostnip is that it is quickly reversible with rewarming.
Frostbite, on the other hand, is the result of tissue injury due to freezing and rewarming. In addition to direct injury to the tissue cells, small blood vessels feeding the tissues are likely damaged causing resultant inflammation, blood clotting, and subsequent poor blood supply to the tissues.
Frostbite most commonly affects the head, hands, and feet. It can occur extremely quickly (within seconds to minutes) when touching very cold metal surfaces or in high wind or high-altitude conditions.
The degree of frostbite can be difficult to determine by visual inspection at the outset of the injury event and can range anywhere from superficial skin involvement to deep injury to muscle and bone. Early signs of frostbite may be challenging to identify in darker skin tones. Patients typically report cold, numbness, and clumsiness of the affected area. The skin is typically discolored and may be hard or waxy to the touch. Blistering may be evident if the area has begun thawing.
What are the risk factors for frostnip and frostbite?
Risk factors include activities or occupations with increased cold exposure including military, outdoor winter athletics, the elderly, the homeless, and those who abuse drugs and alcohol. Exhaustion, dehydration, and malnutrition may decrease the ability to respond to cold conditions.What can you do to prevent cold weather injury?
Adequate layered clothing for the conditions is key. A good base layer should have properties to wick moisture away from the body. Avoid layering too tightly; layers should be somewhat loose to allow air to warm between the layers. The top layer should be impermeable to wind. Be sure your face is also covered. Excessive sweating of the hands and feet can lead to frostbite so gloves and socks should also have moisture-wicking capabilities.
What is the treatment for frostbite?
If you believe you have suffered frostbite you must seek emergency medical attention right away. In the interim, be sure to remove wet and constrictive clothing and protect the affected area against wind. Do not rub the area as it can cause further injury. If possible, immobilize and elevate the area.
References:
Cline, David, et al. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. McGraw-Hill Education, 2020.
Mäkinen, Tiina M., et al. “Occurrence of Frostbite in the General Population--Work-Related and Individual Factors.” Scandinavian Journal of Work, Environment & Health, vol. 35, no. 5, 1 Oct. 2009, pp. 384–393, pubmed.ncbi.nlm.nih.gov/19730758/#:~:text=The%20annual%20incidence%20of%20severe, https://doi.org/10.5271/sjweh.1349.
McIntosh, Scott E., et al. “Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Frostbite.” Wilderness & Environmental Medicine, vol. 22, no. 2, June 2011, pp. 156–166, https://doi.org/10.1016/j.wem.2011.03.003.
Murphy, James V., et al. “Frostbite: Pathogenesis and Treatment.” The Journal of Trauma: Injury, Infection, and Critical Care, vol. 48, no. 1, Jan. 2000, p. 171, https://doi.org/10.1097/00005373-200001000-00036.
Zafren K. Frostbite: Emergency care and prevention. In: In: UpToDate, Connor RF (Ed), Wolters Kluwer. (Accessed on Jan 5, 2024.)