Diagnosis of Frostbite
The diagnosis of frostbite is made based on physical examination. Examination of the history of cold exposure and the severity of tissue damage. Frostbite is usually diagnosed clinically, but in more advanced cases, imaging and other tests may be required to determine the depth of the injury and guide treatment.
Clinical Evaluation
A doctor will assess:
Appearance of the affected area – skin colour, texture, swelling, and presence of blisters
Sensation and movement – to check for numbness or nerve damage
History of exposure – including temperature, wind chill, and duration of cold contact
Symptoms after rewarming – such as pain, return of sensation, and skin changes
Experts typically grade the severity of frostbite into four degrees:
First-degree – superficial, with no blisters
Second-degree – clear blisters and swelling
Third-degree – blood-filled blisters and deeper tissue involvement
Fourth-degree – full-thickness damage to muscle, tendons, or bone
Imaging Tests
In moderate to severe cases, doctors may request:
Doppler ultrasound – to assess blood flow in the affected tissues
Bone scans – to determine the extent of deeper tissue or bone involvement
MRI or Technetium-99 scans – helpful in planning surgery or amputation when necessary
Use these tools several days after rewarming to assess tissue viability.
Laboratory Tests
Perform blood tests to:
Check for infection, especially if blisters have ruptured
Monitor electrolyte levels and general health in severe or systemic frostbite
Screen for rhabdomyolysis if muscle damage seems likely
Distinguishing from Other Conditions
In rare cases, frostbite may be mistaken for:
Chilblains (pernio) – inflammatory lesions from non-freezing cold exposure
Raynaud’s phenomenon – temporary narrowing of blood vessels causing colour change
Trench foot – due to prolonged damp exposure, not freezing
Diagnosis of Frostbite
Accurate diagnosis of frostbite ensures appropriate treatment and helps predict recovery or risk of complications such as amputation or nerve damage.
