Colder temperatures mean snow in the mountains of California, and everywhere in the mid-west and east coast. With an increase in outdoor winter activities and lack of appropriate, heated shelter for the homeless population, we are going to see an increase in cold related injuries at our burn centers.
There are three major categories of cold induced injury, frostnip, chilblain and frostbite.
Frostnip is a mild cold induced injury that produces local paresthesia (numbness, prickling or tingling) that completely resolves with passive external rewarming.
With chilblains (AKA erythema pernio), exposure to cold temperatures causes inflammatory changes in the skin without actual freezing of the tissues. Signs and symptoms of chilblains include painful, itchy, red or purple skin lesions with burning and parathesias. The lesions may blister and there may be local edema. Chilblains, though more severe than frostnip responds well to rewarming and does not require surgical intervention.
Frostbite is a cold induced injury that results in freezing and formation of ice crystals within the tissue. Frostbite may occur when the skin temperature drops below 24.8⁰F to 14⁰F. It can occur at higher temperatures in the presence of wind, immobility, malnutrition, or peripheral vascular disease. Early symptoms include; itching, numbness, prickling and pallor in the affected area. Indications of deeper tissue injury in more severe cases include; white or yellow appearance of the skin, decrease in elasticity and mobility of the skin. May progress to hemorrhagic blistering and necrosis with associated edema and stiffness. Severe cases of frostbite may result in major tissue loss and the need for amputation.
A fourth category of cold injuries not generally associated with outdoor exposure to cold are the Flash-freeze injury and cold contact injury. These are rapid cooling injuries that cause more immediate tissue death compared to the above cold injuries. Causes include contact with chemicals such as liquid nitrogen or dry ice (solid form of carbon dioxide). Flash-freeze and cold contact injuries generally cause immediate cell death, do not improve with rewarming, and may require surgical debridement and soft tissue coverage.
So, what is the best treatment for cold injuries?
Prevention!! For frostnip, chilblains and frostbite prevention, the best advice during winter months is to “keep warm, keep dry, and keep moving.” Wear warm, dry, layered clothing as well as a windproof outer “shell.” Avoid alcohol and tobacco. Maintain circulation in the extremities by moving arms, legs, fingers and toes. Avoid constrictive clothing. Other than prevention, acute treatment of frostbite includes:
Rapid rewarming with 104 – 108⁰F water (avoid warming and re-freezing!)
Ibuprofen 400mg every 12 hours
No tobacco use
Thrombolytic therapy (in select patients)
Winter is a great time to get out and enjoy cold weather activities. So whether you’re a snowboarder, hiker, or cross-country skier, remember to do so responsibly and protect yourself from the cold.