Cold Injuries

Cold can cause direct skin injuries, as in frostbite and trench foot, and it can trigger or worsen underlying skin diseases, as in pernio/chilblains, Raynaud. Frostbite can occur after prolonged and often poorly protected exposure to freezing temperatures. The deeper the injury, the poorer the prognosis. Rapid and controlled rewarming and analgesics are the first steps in the treatment. Trenchfoot can occur after prolonged exposure of the feet to cold, humid, occluded, and often unhygienic conditions. Treatment consists of slow rewarming at room temperature and keeping the feet dry and clean. Pernio is a common skin condition characterized by cold, red to purple, painful, burning, and often itchy macules, papules, plaques, or nodules on the acral parts of the body. In severe cases blistering, wounds, ulcers, and secondary infection can occur. Prevention using gloves and warm socks/shoes is important, and treatment is often difficult. Raynaud phenomenon is an episodic spasm of small arteries as an exaggerated response to low temperature or emotional stress. It is characterized by well-demarcated “tricolore” (white, blue, red) discoloration of the distal parts of the digits/toes. Usually, it is primary. However, it can be a manifestation of underlying disease.