classification of frostbite injuries

Last edited 02/2021 and last reviewed 03/2021

Frostbite injuries can be classified into grades 1 to 4 depending on the clinical presentation after rewarming (1,2)

• grades 1 to 2 comprising superficial frostbite injuries
• grade 1, cyanosis is absent, andthe risk of amputation is minimal
• grade 2 frostbite presents with cyanosis on the distal phalanx of fingers or toes, and isassociated with a moderate risk of amputation
• grades 3 to 4 deep frostbite injuries
• grade 3 frostbite injury
• cyanosis upto the metacarpophalangeal joint (MCP; base of the fingers) or metatarsophalangeal joint (MTP; middle of the foot)
• bears a high risk of amputation
• grade 4 injuries
• cyanosis is seen proximal to the MCP or MTP joint
• the risk of amputation is almost 100% (2)

Reference:

• Handford C, Buxton P, Russell K, Imray CE, McIntosh SE, Freer L,et al. Frostbite: a practical approach to hospital management.Extreme Physiology & Medicine 2014;3:7
• Cauchy E, Chetaille E, Marchand V, Marsigny B. Retrospective study of 70 cases of severe frostbite lesions: a proposed new classification scheme. Wilderness & Environmental Medicine 2001;12(4):248-55