Frostbite & Frostnip

What is the difference between Frostbite and Frostnip? 

Frostnip is the condition when the superficial portion of the skin (the epidermis) is injured by cold.  The skin becomes blanched, and sensation becomes altered, such that numbness and tingling occur.  As the skin is warmed, it turns red and may be painful. 

Frostbite is the condition of a deeper tissue injury from cold.  It is characterized by a partial or full-thickness cold injury to the dermis (the skin layer below the epidermis).  Frozen tissues look white and often feel soft and spongy.  As the skin is warmed, it turns red and involves substantial pain.  Blisters may occur. 

Severe, deep, frostbite will result in a tissue with a lifeless appearance and a heavy, wooden, solid feel. 

Frostbite is most frequent in high altitudes, where there are diminished oxygen levels, and in tissues furthest from the heart.   

How are these injuries treated? 

So long as there is no danger of any re-exposure to cold or the possibility of re-freezing the tissue, it is best to rapidly warm the affected part in warm water.  Aim for water about 40 degrees Celsius or about 105 degrees Fahrenheit.  The skin should not be rubbed to warm up the tissue, as this may cause further damage to the tissues.  If the tissues may be re-exposed to the cold, it is best to put off rewarming the tissue, as refreezing causes even more damage than the initial freezing. 

Any blisters are usually left intact, but when they are broken, the tissue should be properly cleansed with an iodine solution and normal saline, then dressed with a Silvadene dressing. 

Depending upon the depth of tissue injury, strong analgesics may be necessary to control pain.  

The patient should not smoke, as this will cut down on circulation to the injured tissues.  

In severe cases, the patient may need to be admitted to the hospital, especially if hypothermia has occurred.