A 13-year-old female came to clinic with a 2-day history of foot discoloration, pain, pruritis and edema. Walking or pressure did not change the symptoms, but exposure to a heating pad or warm water soaks did improve them. She denied any problems elsewhere in her body, and was not known to have had frostbite, previous cold exposures or reactions to cold such as a Raynaud-like reaction. She denied any medications and had no fever, weight change, cold or heat intolerance, eye changes, or joint or muscle problems.
The past medical history showed she had tested positive for COVID-19 along with her family approximately 3 weeks previously. During that time she had mild cough and fever that resolved within a few days without additional problems. The family history was negative for autoimmune or rheumatological diseases but had some heart attacks and strokes.
The pertinent physical exam showed a healthy female with normal vital signs. Her growth was at the 50-75%. Her examination was normal except for her feet which were mottled or a reddish-purple to whitish coloring. Most of the foot was involved including the heel but changes stopped around the malleoli. Her middle toes bilaterally were somewhat swollen and she said had intermittent pain or itching.
The diagnosis of chilblains was made. It was thought to be due to her recent COVID-19 infection. She was started on topical steroids and recommended to wear warm socks and monitor for additional symptoms. She and her guardian were counseled regarding chilblains nature history also.
Chilblains is also known as perniosis is an “…inflammatory dermatosis that generally affects the dorsal feet or hands during the periods of damp and cold, but not freezing, conditions…” It produces acryl lesions.
Chilblains may be derived from the Old English words “chill” and “blegen” (sore). Pernio is thought be derivative of pern(a) or haunch of the leg as the feet and legs are commonly affected. Chilblain is usually idiopathic but has been associated with Raynaud disease, blood problems including cryofibrinogenemia and rheumatologic conditions such as systemic lupus erythematosus, rheumatoid arthritis and antiphospholipid syndrome.
It should be distinguished from livedo reticularis and usually is more easily distinguished from acrocyanosis. Livedo reticularis is a net-like, red-purple skin discoloration that is caused by abnormal circulation in the affected area. It can simply occur because the area or the person is cold. Acrocyanosis a persistent, painless, deep-bluish color due to decreased oxygenated blood which usually is benign. A review and differential diagnosis of acrocyanosis can be found here.
Since the COVID-19 pandemic, the diagnosis of chilblains has increased along with other vascular and dermatological conditions such as MIS-C.
Data is early but increasingly there is a strong association with COVID-19.
Chilblains due to COVID appears the same histologically as other etiologies.
A retrospective cohort study with geolocation of potential cases and COVID-19 incidence found that there was a large increase in case incidence during the COVID-19 pandemic but there was low testing positivity and therefore a weak correlation with COVID-19 incidence. Before COVID-19 the annual incidence (2016-2020) was 5.2 per 100,000 person-years, but rose to 28.6 during the pandemic. The authors hypothesize that this may be due to more children being affected and who may not be symptomatic of COVID, or may not mount as robust an immune response so is a false-negative testing, or the testing itself could be a problem.
Before the pandemic, 20-39 year olds and > 60 year old had the highest incidence. During the pandemic, school age children had the highest incidence rising from before the pandemic from 9.1 to 62.7 per 100,000 person years. This is approximately 3x the incidence of the other age groups studied. Before and during the pandemic Asian-American and White races were more affected than others (at a much higher rate for all groups) and females were more affected than males.
Another study of pooled case reports and observational studies (N = 715) found that the average patient age was 16.6 years old, and had a slight male prevalence. Chilblains occurred in the feet in 91.4%, hands in 17.9% and both in 11.7%. Foot involvement was even more common in those under 20 years than those over 20 years old (92% vs 72.6%). Pruritis (35.8%) and pain (24.8%) were common but 35.7% were asymptomatic. Common presentation was macules and papules that were red or violaceous with edema occurring in 31.8% for those under 20 years. Potential COVID-19 infection was reported in 50.2%.
In studies, overall patients did well with most having improvement in symptoms within a few weeks (up to 60 days has been reported). Some patients were treated with topical steroids which may improve symptoms.
Questions for Further Discussion
1. How are MIS-C and Kawasaki Disease different than chilblains? A review can be found here.
2. How do you treat immersion foot injury? A review can be found here.
3. How do steroid medication supposedly improve symptoms of chilblains?
4. How do you grade frostbite? A review can be found here.
- Age: Teenager
To Learn More
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Hedrich CM, Fiebig B, Hauck FH, et al. Chilblain lupus erythematosus–a review of literature. Clin Rheumatol. 2008;27(8):949-954. doi:10.1007/s10067-008-0942-9
Kolivras A, Thompson C, Pastushenko I, et al. A clinicopathological description of COVID-19-induced chilblains (COVID-toes) correlated with a published literature review. J Cutan Pathol. Published online August 9, 2021:10.1111/cup.14099. doi:10.1111/cup.14099
Rocha KO, Zanuncio VV, de Freitas BAC, Lima LM. “COVID toes””: A meta-analysis of case and observational studies on clinical, histopathological, and laboratory findings. Pediatr Dermatol. 2021;38(5):1143-1149. doi:10.1111/pde.14805
Epidemiologic Analysis of Chilblains Cohorts Before and During the COVID-19 Pandemic | Dermatology | JAMA Dermatology | JAMA Network. Accessed February 22, 2022. https://jamanetwork.com/journals/jamadermatology/fullarticle/2781362
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa