Chilblains in our country generally occur in winter and early spring, and are more common in the Yangtze River basin than in the north. This is because, although the winter climate in the Yangtze River basin is warmer than in the north, it is more humid, and the cold protection measures are less adequate compared to the northern regions. Children often neglect to protect themselves from the cold, so chilblains are common among them. Trench foot and immersion foot used to occur mostly during wartime; the former is caused by standing in trenches at temperatures between 1 to 10°C for long periods, while the latter is caused by standing in cold water. In peacetime, these two types of cold injuries can also occur in certain situations such as construction work, working in paddy fields, or military duty.

bubble_chart Pathological Changes

When the local skin of the body is exposed to low temperatures above freezing, vasoconstriction and slowed blood flow occur, affecting cellular metabolism. After the local area returns to normal temperature, blood vessels dilate, become congested, and exudation occurs. In more severe cases, fluid accumulates under the epidermis (blisters). Some capillaries and even small arteries and veins may develop thrombosis after being damaged, leading to tissue necrosis.

bubble_chart Clinical Manifestations

The onset of the disease is often unnoticed, and it is usually only when redness and swelling appear in areas such as the feet and hands that it becomes noticeable. There may be itching or stabbing pain when warmed. Blisters may form; after the epidermis is removed, the wound surface becomes red and exudes fluid; after infection, erosion or ulcers may form. Non-freezing cold injuries often have individual predisposing factors, so not everyone under the same conditions will develop the disease. Chilblains are also prone to recurrence, possibly due to reduced local skin resistance after the illness. Some individuals who have recovered from trench foot or immersion foot may experience pain, numbness, and pallor in the affected foot when exposed to low temperatures again, and it may even induce occlusive vascular disease.

After chilblain occurs, chilblain ointment can be applied to the affected area with intact epidermis, and warm compresses should be applied several times a day. For areas with erosion or ulcers, an ointment containing antibacterial agents and corticosteroids can be used, or chilblain ointment may also be applied. For trench foot and immersion foot, in addition to local treatment, it is advisable to use certain Chinese medicinals that warm the meridians, unblock the collaterals, invigorate blood, and resolve stasis to improve limb circulation.

bubble_chart Prevention

People working or on duty outdoors in winter should have cold-proof and waterproof clothing. Those who have suffered from chilblains, especially children, should pay attention to keeping their hands, feet, and ears warm during the cold season, and can apply certain anti-chilblain creams.