Eighteen-year-old, NorAm skier, NCAA Division I Rugby player, and lover of the outdoors, presents to the clinic complaining of cold, painful hands. She states hands always feel cold, and in cold weather they are extremely painful. Blood tests to rule out vascular disease were normal. What could be the cause of this?

Normally, in cold weather our bodies work to keep essential organs functioning. Skin is not considered essential. When exposed to cold, blood vessels constrict, decreasing blood flow to the skin. Because the metabolic demand of our skin is low, more important organs like our heart and brain need the blood flow. Paradoxically, exposure to cooler temperatures like those below 15 degrees Celsius or 59 degrees Fahrenheit can cause cold-induced vasodilation. This allows blood to flow to the skin to help prevent more serious injury or frostbite. The vasodilation cycles in 5- to 10-minute intervals.

Nonfreezing cold injury (NFCI) occurs when tissues are damaged due to prolonged cooling exposure, but not freezing temperatures. NFCI is due to exposure of the extremities to temperatures around 0 to 15°C or 32 to 59°F, commonly the hands and feet. Current theory is that NFCI is due to a combination of vascular and neural dysfunction. With prolonged vasoconstriction, the skin experiences reduced blood flow with a neurological component influencing the damage as well.

Some patients living in cold environments like the Inuit, Sami people, and Nordic fisherman have a larger cold-induced vasodilation response and more rapid cycling. This is thought to decrease their risk of NFCI. Is it possible that patients who develop NFCI have a smaller and slower cycling of their cold-induced vasodilation? Could this be the issue with our patient with NFCI?  Further research is needed to learn more about NFCI and find better ways to treat it.

What we do know is there are 4 Stages of NFCI:

Stage 1: During the cold exposure – Loss of sensation, numbness, clumsiness. Usually painless unless rewarming is attempted.

Stage 2: Following cold exposure – occurs during and after rewarming. Skin can develop a mottled pale blue-like color, area continues to feel cold and numb, possible swelling. Usually lasts a few hours to several days.

Stage 3: Hyperemia – affected area becomes red and painful. Begins suddenly and lasts for several days to weeks.

Stage 4: Following hyperemia – affected areas appear normal but are hypersensitive to the cold. Areas may remain cold even after short exposure to the cold. This stage can last for weeks to years.

Outdoor paddle sports like kayaking and canoeing put patients at greatest risk due to the continual exposure to the cold, wet environment. It was thought that in order to have NFCI, one had to be exposed to both cold and wet environments. However, it has been shown that this is not always the case. Like in our patient, exposure to just cold environment can trigger the syndrome. Our 18-year-old patient is an avid skier and spends most of the winter on the mountain. It was also noted that she enjoys paddleboarding and kayaking, which were recognized as triggers for the hand pain. We are unable to determine exactly what caused our patient to develop this syndrome. But we do know it affects their life significantly.

 We choose to live in the mountains because of the things we love. Whether it is hiking, biking, skiing, kayaking, paddleboarding, or the hundreds of other activities offered in this area, we are at risk of NFCI. Currently, there is no good treatment for this syndrome. Prevention is  best. The purpose of this blog is to share information about staying healthy at high altitude. Sharing this information on the stages of NFCI with friends and family will help prevent this painful, debilitating syndrome.

Resources

Nonfreezing cold water (trench foot) and warm water immersion injuries. UpToDate. https://www.uptodate.com/contents/nonfreezing-cold-water-trench-foot-and-warm-water-immersion-injuries/print#:~:text=Nonfreezing%20cold%20injury%20%E2%80%94%20NFCI%20is,to%2059%C2%B0F)%20conditions. Accessed July 14, 2022.

Oakley B, Brown HL, Johnson N, Bainbridge C. Nonfreezing cold injury and cold intolerance in Paddlesport. Wilderness & Environmental Medicine. 2022;33(2):187-196. doi:10.1016/j.wem.2022.03.003

Rachel Cole is a Physician Assistant Student at Red Rocks Community College in Denver, Colorado. She originally grew up in Salt Lake City, Utah, where she learned to love the outdoors. She studied Biology at Western Colorado University in Gunnison, Colorado prior to PA school. She played soccer for the college and fell in love with Colorado and small mountain towns. When she is not studying for school, she enjoys skiing, hiking, backpacking, fishing, waterskiing, canyoneering, and any other activities that get her outside. After graduation she hopes to practice family medicine in a rural community in the mountains.