Cold Injuries

by admin on December 8, 2013

‘Tis the season for frostbite, and other cold injuries.  When discussing cold injuries, the feet are usually part of the conversation because the feet and toes are the most common areas affected by frostbite.  Frostbite is the freezing of body tissue from external cold exposure.  The effects may be temporary or permanent, depending on the length of exposure to the cold, and how deeply the tissues were frozen.  Circulation is the biggest individual factor, since areas with poor circulation are most at risk (extremities, especially if there is not a good network of blood vessels, like in the fingers, toes, nose, and ears.)

The issue of circulation can be a gray area.  Some people have diagnosed circulatory disease, or a disease that can cause damage to the circulatory system (like diabetes), while other people may say they have “bad circulation” for one reason or another.  Usually this is because people feel like their hands and feet get cold easily, although there may not be anything medically wrong with them.  The way that our body reacts to cold exposure is to cut off circulation to the extremities to keep the warm blood flowing in the core, thus reducing the chances of hypothermia.  So in a way, it is normal for us to have cold feet in the winter.  Some people are just more efficient “heat preservers” than others.  Other things that reduce circulation are smoking and beta-blocker drugs.

The body’s downplay of circulation to the extremities in cold weather conditions, however, is exactly what opens the door for frostbite to occur.  If circulation to the extremity is cut down and the temperature below freezing, frostbite can occur.  Factors that make it happen faster are the same risk factors for hypothermia, like windchill and wet clothing.  Unlike hypothermia, where the body temperature lowers below normal, in frostbite the affected part of the body actually freezes.  Because of the way frostbite occurs, the skin is affected first, then the connective tissues, and then bones and joints.  In the medical field, frostbite is classified into degrees of severity, like burns.

First degree frostbite is a short-term freezing of the skin.  The skin will usually1st Degree Frostbite turn red or purple, and often only a particular spot of skin will show discoloration.  The area will be painful, but heals within a week typically.  Second degree frostbite involves the skin full-thickness.  It looks like first degree on day one, but the more severe effects are felt in the days after, when blisters form and burst, leaving the skin to slough off.  This too will heal, but requires skilled wound care, so if you get blisters it is time to see a doctor.  With third degree frostbite the freezing occurs beyond just the level of the skin, affecting 1st Degree Frostbitemost notably the nerves.  Blisters do not occur; the skin will look waxy and different, and not change color back to normal.  Small areas can be treated like second degree frostbite while larger areas may result in death of the tissue that will lead eventually to amputation.  Fourth degree frostbite is freezing all the way through.  The image of a black, shriveled finger or toe is what most people think of when they think of frostbite – there is no coming back.  Amputation is the only treatment for the fourth degree.

The vast majority of frostbite injuries are first or second degree, and it is important to know how to take care of a suspected frostbite injury.  Rapid rewarming is a concept in emergency medicine that basically involves submerging the frostbitten part in warm (105 degree) water to stop the cold damage and open up the blood flow to the area again.  Prompt attention to the matter and rapid rewarming can reduce the severity of frostbite by a whole level.

Of course, people don’t necessarily know when they’ve passed the invisible line between just a cold toe and a frozen one.  This is where prevention is key.  Obviously the colder it is, the faster you can get frostbite.   If it is below zero, try to minimize time outside in general.  If socks or gloves get wet, change them immediately.  When fingers and toes start to tingle, get them to a warm place, or better yet, get inside.  As I said before, risk factors for frostbite are also the risk factors for hypothermia, which is a much more serious condition that can be fatal if not treated.  So beyond the fingers and toes, if you become lightheaded, confused, weak, or shiver uncontrollably, get to an ER immediately.

Stay warm this winter.

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