They are common in countries with damp, cold weather. Most frequently occurring in the winter.
- Sign&Symptoms: typically, present with burning and itching of body extremities. The affected skin may also swell and turn red or dark blue. In severe cases, the skin surface may break, and sores or blisters may develop.
- Location: most often affecting body’s extremities, such as the toes, fingers, heels, ears and nose.
- Treatment: typically heal within a few weeks by avoiding further exposure to cold or wet environments
- Prognosis: Chilblains can be uncomfortable, but rarely cause any permanent damage.
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Chilblains are also known as pernio or chill burns. Chilblains are a medical condition occurring in predisposed individual when exposed to cold and humidity, causing tissue damage.
Chilblains are often confused with frostbites- the main difference being that Chilblains are abnormal skin reaction to nonfreezing cold, whereas a Frostbite is freezing of a peripheral body part, meaning that the tissue may undergo necrosis if not carefully and promptly managed.
Recent studies have found a correlation between COVID-19 and chilblain-like symptoms.
What causes chilblains?
Cold temperatures cause the most superficial vessels in the skin too narrow, known as vasoconstriction, whereas warm temperatures cause them to enlarge (vasodilation).
In the event of a sudden temperature change, superficial blood vessels of the skin cannot always handle the increased blood flow, resulting in blood leakage into the surrounding tissue, which causes the swelling and itchiness associated with chilblains.
Symptoms of Chilblains
Chilblains usually appear several hours after exposure too cold, non-freezing temperatures on extremities such as the toes, fingers, heels, ears, and nose. They typically present with a burning and itching sensation in the affected areas, which can become more intense when suddenly moving to a warm environment. The affected skin may also swell and turn red or dark blue. In severe cases, blisters may appear. It is strongly recommended avoiding scratching the skin as it is fragile and can break easily, likely resulting in infection.
- Avoid excessive washing with water and soap.
- Protect the sensitive skin from excessive heat or cold.
- Use mild soap and unscented products designed specifically for dry and sensitive skin.
- Do not use excessive detergent to wash the clothes and sunbathe in moderation.
- Avoid wool clothing, which can cause irritation and itch, and synthetic clothing, which can make the skin feel trapped.
What makes COVID-19 Chilblains different?
The pathophysiology behind chilblains is due to an abnormal reaction to cold temperatures, which causes the most superficial blood vessels to constrict, resulting in blood leakage into the surrounding tissue. This leads to the swelling and itchiness associated with chilblains. It is argued, however, that chilblains related to COVID-19 may be a result of microthrombi formation in the peripheral small vessels, not allowing sufficient circulation to the toes. A different mechanism giving the same symptoms and presentation as the cold provoked chilblains. In support of this theory, there are many new studies demonstrating how complement associated microvascular injury and thrombosis are the base of both pulmonary and skin manifestations of severe Corona virus infection. This opens new research possibilities, as experimentation treatments with Low molecular Heparin (first line treatment in coagulopathies) shows strong association with decreased mortality in patients affected by COVID-19 disease.
What can I do?
If you experience frequent chilblains, you can reduce your risk of developing them by:
- Limiting your exposure to the cold
- Wearing warm gloves or socks
- Avoiding smoking, as nicotine is a vasoconstrictor
- Keeping active, as this helps improving your circulation
- Warming your shoes and making sure they are fully dry before you wear them
- If your skin gets cold, warm it up gradually! Sudden temperature change is one of the main causes of chilblains.
Should I seek medical care?
Chilblains usually heal within a few weeks and do not cause any permanent problems.
Seek medical advice if you have:
- Severe or recurring chilblains
- Chilblains persisting for a few weeks
- Chilblains infection- swelling and pus or a high temperature (fever) of 38C (100.4F) or above
- Ulceration of the affected skin
Treatment of Chilblains
Chilblains often get better on their own after a week or two without treatment.
It may help to use a soothing lotion to relieve itching, such as 1% hydrocortisone, calamine or witch hazel. You may as well ask your pharmacist to recommend a suitable product.
If your chilblains are persistent and severe, consult your GP or dermatologist
Read more on Covid-19 here
Coronavirus (COVID-19) infection-induced chilblains: A case report with histopathologic findings. Kolivras A, et aL. JAAD Case Rep. 2020 Apr 18.
Chilblains. Nyssen A, et al. Vasa. 2020 Mar;49(2):133-140.
Pernio (Chilblains). Whitman PA, Crane JS. StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan- 2019 Nov 4.
Complement associated microvascular injury and thrombosis in the pathogenesis of severe COVID-19 infection: A report of five cases
Cynthia Magro,a J. et al Elsevier Public Health Emergency Collection Submitted for Publication April 9, 2020; accepted for publication April 9, 2020.
Anticoagulant Treatment Is Associated With Decreased Mortality in Severe Coronavirus Disease 2019 Patients With Coagulopathy. Ning Tang 1, et al. J Thromb Haemost. 2020 May;18(5):1094-1099.
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Dr Carol Mastropierro is a practicing doctor in the UK, currently pursuing a degree in dermatology. Her passion is healthy skin.