frostbite

Classification

• much like burns
• 1st degree: skin irritation
• 2nd degree: blisters, reversible damage
• 3rd degree: all layers of skin affected; irreversible damage

Etiology

• exposure to temperatures below freezing point of skin

Pathology

• tissue freezes
• nose, cheeks, ears, fingers, toes extremities) are most commonly affected
• ice crystals form in the extracelluar space resulting in dehydration of cells
• vascular injury results in extravasation of blood, vascular occlusion & ischemia
• interior of cells rarely freezes

Clinical manifestations

• paresthesias, numbness
• blistering & edema
• pain & purpura may occur on rewarming
• dull pain may become throbbing in 2-3 days follwowing rewarming
• pain may last for weeks

Management

• remove from exposure to cold
• treatment of associated hypothermia (if present) takes priority
• elevate involved area to reduce edema
• remove restrictive, wet clothing
• warm fluids (no alchohol, caffeine)
• immerse affected area in water bath heated to 40-42 C (104-107.6 F) until thaw complete
• opiates as needed to diminish pain
• treat associated dehydration (if present)
• debride clear blisters; leave bloody blisters intact to preserve viable blood vessels
• hospitalize 1-2 days (most patients)
• surgery consult if need for amputation contemplated

More general terms

• cold injury
• superficial injury/trauma

Additional terms

• chilblain
• hypothermia