Frostbite is a limited, bruised, inflammatory disease of the skin in the terminal areas that occurs during the cold season. Frostbite etiology Cold is the main cause of frostbite development. The cause of frostbite is the contraction of small local arteries when the skin is cold (0-10°C), humid, or when there is a rapid change in temperature or cold. In addition, the patient’s own skin humidity, peripheral microvascular malformation, autonomic nerve dysfunction, malnutrition, endocrine disorders and other factors may also be involved in the development. Lack of exercise, sweaty hands and feet, tight shoes and socks, and long-term outdoor work at low temperatures can all contribute to the development of frostbite. Clinical manifestations of frostbite Frostbite occurs in early winter and early spring, and is most common in children, women and those with poor peripheral blood circulation, often accompanied by cold skin at the ends of the limbs, cyanosis and excessive sweating. The lesions are often found on the fingers, back of the hands, face, ears, toes, edges of the feet, heels, etc., and are often distributed bilaterally. The common damage is a limited bruised dark purple-red raised edematous erythema with indistinct boundaries, bright red edges, tense and shiny surface, and soft texture. Local pressure can be discolored, and the red color gradually returns after pressure is removed. In severe cases, blistering may occur and rupture to form vesicles or ulcers, leaving pigmentation or atrophic scar after healing. Itching is obvious and intensifies when exposed to heat, and ulcers are painful. There is a specific type of frostbite mostly seen on the femur in women. Clinically there are characteristic bluish-red infiltrative patches, symmetrically distributed on the lateral aspect of the overweight femur, occasionally with secondary ulceration and often combined with follicular keratosis. These lesions are exclusively associated with cold exposure and subside in warm environments. Diagnosis of frostbite Based on the onset of the cold season, the characteristic distribution of the lesions and the characteristics of the rash, the diagnosis is not difficult and no other ancillary tests are required. However, it needs to be differentiated from diseases such as systemic lupus erythematosus, erythema multiforme, dry syndrome, cryoglobulinemia, and cyanosis of the extremities. Treatment of frostbite 1. Systemic treatment Oral vasodilators such as nicotinamide and nifedipine. 2.Local treatment Helium-neon laser and infrared irradiation are available, or laser point irradiation (foot Sanli, Fuyao, etc.) followed by local scattered-focus universal irradiation of frostbite. If the frostbite is not broken, you can use compound heparin ointment, polysulfate mucopolysaccharide cream, vitamin E ointment, etc. For those who have broken down, topical antibiotic ointment such as 5% boric acid ointment, 1% erythromycin ointment, and red light physiotherapy are used. Frostbite prevention 1. Strengthen exercise, promote blood circulation, and improve the body’s ability to adapt to cold; 2. Pay attention to anti-freezing, keep warm to prevent humidity, and do not wear tight shoes and socks; 3. blood circulation.