Author: Hon A/Prof Amanda Oakley, Dermatologist, Hamilton, New Zealand, 1999.
Chilblains are itchy and/or tender red or purple bumps that occur as a reaction to cold. Chilblains are also known as pernio or perniosis. They are a localised form of vasculitis.
Severe cold injury can also damage the small bones in the digits, leading to microgeodic disease, swelling and sometimes, bone fracture.
Chilblains most often affect children and the elderly in damp, temperate climates.
Chilblains occur several hours after exposure to the cold. Cold causes constriction of the small arteries and veins in the skin. The chilblains are sometimes aggravated by sun exposure, because rewarming results in leakage of blood into the tissues and swelling of the skin.
Chilblains are less common in countries where the cold is more extreme because the air is drier and people have specially designed living conditions and clothing.
Chilblains are more likely to develop in those with poor peripheral circulation, noted by blue-red mottled skin on the limbs (acrocyanosis).
Other factors contributing to chilblains include:
Each chilblain comes up over a few hours as an itchy red swelling and subsides over the next 7–14 days or longer. In severe cases, blistering, pustules, scabs and ulceration can occur. Occasionally the lesions may be ring-shaped. Chilblains may become thickened and persist for months.
Common sites for chilblains are:
Unfortunately chilblains respond poorly to treatment. The following may be useful:
People with a tendency to chilblains must keep their hands and feet warm to reduce the risk of chilblains.
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