Chilblains are itchy and/or tender red or purple bumps that occur as a reaction to cold. The condition is also known as pernio or perniosis, and is a localised form of vasculitis.
Children and the elderly are most often affected. In children recurrences each winter for a few years are common but complete recovery is usual. Chilblains in elderly people have a tendency to get worse every year unless precipitating factors are avoided.
Severe cold injury can damage the small bones in the digits, leading to microgeodic disease, swelling and sometimes, bone fracture.
What is the cause of chilblains?
Chilblains are due to blood vessel shut-down in cold conditions. They occur several hours after exposure to the cold in temperate humid climates. They are sometimes aggravated by sun exposure. Cold causes constriction of the small arteries and veins in the skin and 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 i.e. blue-red mottled skin on the limbs. In some cases they are due to connective tissue disease, particularly lupus erythematosus.
Contributing factors include:
- A familial tendency
- Peripheral vascular disease due to diabetes, smoking, hyperlipidaemia
- Low body weight, or poor nutrition e.g. anorexia nervosa
- Hormonal changes: chilblains can improve during pregnancy
- Connective tissue disease, particularly lupus erythematosus or, in association with Raynaud phenomenon, systemic sclerosis.
- Bone marrow disorders
What do chilblains look like?
Each chilblain comes up over a few hours as an itchy red swelling and subsides over the next 7-14 days. In severe cases blistering, pustules, scabs and ulceration can occur. Occasionally the lesions may be ring-shaped. They may become thickened and persist for months.
Common sites for chilblains are:
- Backs and sides of the fingers and toes
- Lower legs
- Thighs especially in horse riders
- Wrists of babies
- Over fatty lumps (lipomas)
Treatment of chilblains
Unfortunately chilblains respond poorly to treatment. The following may be useful:
- Topical corticosteroid cream applied accurately for a few days to relieve itch and swelling
- Antibiotic ointment or oral antibiotics for secondary infection
Prevention of chilblains
The hands and feet must not be allowed to get cold. DO NOT SMOKE! Nicotine constricts the blood vessels.
The following measures may help to keep you warm:
- Insulated and heated home and workplace stop up all draughts
- Warm clothing especially gloves, thick woollen socks and comfortable protective footwear. Keep the head and neck warm with hat and scarf. Have layered clothing on your body.
- Avoid medicines that might constrict blood vessels: these include caffeine, decongestants and diet aids.
- Before going outside, soak hands in warm water for several minutes to warm hands through then dry thoroughly
- Exercise vigorously before going outside
- Wear cotton-lined waterproof gloves for wet work
- Apply sunscreen to exposed skin even on dull days
- Take vasodilator medication such as nifedipine prescribed before the onset of cold weather and taken throughout winter. Side effects may include flushing and headache.