Chilblains · What Is It, Causes, Signs, Symptoms, and More

Published: Aug 21, 2025

Author: Georgina Tiarks, MD•

Editor: Alyssa Haag, MD•

Editor: Emily Miao, PharmD, MD•

Editor: Kelsey LaFayette, DNP, ARNP, FNP-C•

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Illustrator: Jessica Reynolds, MS•

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What are chilblains?

Chilblains, also known as pernio or perniosis, are a form of localized blood vessel inflammation caused by an atypical reaction to cold, non-freezing temperatures. Chilblains result in sensitive, itchy skin lesions with a reddish discoloration that may appear after prolonged or repeated exposure to cold, damp conditions. They typically occur 12 to 24 hours after the exposure and can last up to 3 weeks.

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What causes chilblains?

Chilblains are caused by the effect of cold weather on the small blood vessels of the skin. When the skin is exposed to cold temperatures, particularly in damp conditions, small blood vessels near the skin’s surface constrict to prevent heat loss. Upon rewarming, blood vessels dilate too quickly, leading to leakage of blood into surrounding tissues. These sudden changes trigger an inflammatory response that causes localized swelling, redness, and itching. The exact underlying mechanism remains unclear, but it likely involves an exaggerated vascular response to temperature changes in susceptible individuals. Humidity or dampness exacerbates the problem by increasing heat loss from the skin, accelerating cooling and subsequent vasoconstriction.

Several risk factors increase an individual’s risk of developing chilblains, which include tobacco use, inadequate nutrition, having a low body mass index (BMI), and certain medical conditions such as autoimmune disorders (e.g., lupus erythematosus, Raynaud syndrome) and hematological disorders (e.g., leukemia and lymphomas). Chilblains may also be familial and run in families, meaning there may be a genetic component.

During the COVID-19 pandemic, some individuals infected with the SARS-CoV-2 virus developed chilblain-like lesions primarily affecting the toes, which led to the term “COVID toes”. These lesions resemble classic chilblains but occur in the context of COVID-19 infection and can arise even in warm weather, which is unusual for typical chilblains. While the exact mechanism is unclear, they are likely linked to immune, vascular, or thrombotic processes triggered by the virus.

What are the signs and symptoms of chilblains?

The signs and symptoms of chilblains include sensitive, itchy, and burning nodules with surrounding red patches on skin areas exposed to cold, damp conditions, such as hands and feet. These blistering bumps can ulcerate and scab, over time. This condition occurs most often in the fall or early spring due to the likelihood of inefficient use of cold protective gear.

How are chilblains diagnosed?

Chilblains can be diagnosed based on a thorough physical examination and medical history. Clinical criteria for the diagnosis include the presence of typical lesions in acral areas (e.g., fingers, toes, ears, nose) and a history of exposure to cold with improvement of lesions in warm weather. Additional tests are not needed to diagnose chilblains but may be performed to rule out underlying medical conditions, especially autoimmune and vascular disorders. Initial laboratory tests may include a complete blood count, inflammatory markers (e.g., CRP), and antinuclear antibodies. Skin biopsy is generally not recommended for the diagnosis because findings are non-specific but may be performed if the diagnosis is unclear.

How are chilblains treated?

Treatment for chilblains relies on symptomatic management and preventive strategies to avoid recurrences. Topical corticosteroids may be used to relieve some of the uncomfortable itching or burning symptoms. In more severe cases, medications like nifedipine, a calcium channel blocker, may be prescribed to dilate blood vessels and improve circulation.

For prevention, susceptible individuals may be recommended to avoid spending a lot of time outdoors in cold, damp weather and use cold weather clothing and gear, such as gloves and jackets, when necessary. Additionally, rewarming should be done slowly rather than with sudden exposure to heat (e.g., holding hands close to a heater or fireplace). Smoking cessation can also help to prevent the onset of chilblains by improving circulation.

What are the most important facts to know about chilblains?

Chilblains are painful, itchy, red blisters that arise typically on the hands and feet after exposure to cold temperatures and damp conditions. This most often occurs during the fall and spring seasons, where temperatures hover just about freezing. When an individual is cold, the blood vessels constrict to prevent further heat loss. During rewarming, these vessels dilate too quickly, causing leakage of blood into neighboring tissue. Generally, chilblains can be diagnosed based on a physical examination, however, a skin biopsy may be done in cases where the diagnosis is uncertain. Treatment includes avoiding cold climates, smoking cessation, using cold protective clothing, and rewarming the body slowly after exposure to the cold. Studies have shown limited efficacy with topical treatments and systemic medications.

Key Takeaways

Definition	Chilblains are a form of localized blood vessel inflammation caused by an atypical reaction to cold, non-freezing temperatures, resulting in sensitive, itchy skin lesions with a reddish discoloration.
Causes	- Exposure to cold temperatures, particularly in damp conditions - Cold → vasoconstriction of small superficial blood vessels → rewarming → quick vasodilation → leakage of blood → inflammation - Risk factors: - Tobacco - Inadequate nutrition - Low BMI - Autoimmune disorders - Hematological disorders - Genetic predisposition - COVID-19 infection (even in warm weather)
Signs and Symptoms	- Sensitive, itchy, burning nodules with surrounding red patches - Progression to ulceration and scabbing - Areas exposed to cold and damp conditions (hands and feet)
Diagnosis	- Physical examination → lesions in acral areas - Medical history → exposure to cold and improvement in warm weather - Laboratory tests (for exclusion of underlying conditions) - Complete blood count - Inflammatory markers - Antinuclear antibodies - If unclear diagnosis → skin biopsy
Treatment	- Symptoms management: - Topical corticosteroids - Calcium channel blockers (severe cases) - Prevention: - Avoid spending too much time in cold, damp weather - Use appropriate clothing and gear - Slow rewarming - Smoking cessation

References

Dubey S, Joshi N, Stevenson O, Gordon C, Reynolds JA. Chilblains in immune-mediated inflammatory diseases: A review. Rheumatology (Oxford). 2022;61(12):4631-4642. doi:10.1093/rheumatology/keac231

Nyssen A, Benhadou F, Magnée M, André J, Koopmansch C, Wautrecht JC. Chilblains. Chilblains. Vasa. 2020;49(2):133-140. doi:10.1024/0301-1526/a000838

Pratt M, Mahmood F, Kirchhof MG. Pharmacologic treatment of idiopathic chilblains (pernio): A systematic review. J Cutan Med Surg. 2021;25(5):530-542. doi:10.1177/1203475421995130

Singh H, Kaur H, Singh K, Sen CK. Cutaneous manifestations of COVID-19: A systematic review. Adv Wound Care (New Rochelle). 2021;10(2):51-80. doi:10.1089/wound.2020.1309

Sohier P, Matar S, Meritet JF, Laurent-Roussel S, Dupin N, Aractingi S. Histopathological features of chilblain-like lesions developing in the setting of the COVID-19 pandemic. Arch Pathol Lab Med. 2020;145(2):137-144. doi:10.5858/arpa.2020-0613-SA