TORONTO — Researchers believe they have uncovered why some people developed inflammation and lesions on their toes and feet after contracting COVID-19.
In a study published in the British Journal of Dermatology on Tuesday, researchers from the University of Paris in France focused on how the immune system plays a role in the development of the skin condition called “chilblain-like lesions” or “COVID toes.”
The skin condition primarily affects the toes, although the fingers can also be affected, and is characterized by blueish-red or purple bumps or blisters, redness, and swelling.
While for some it’s painless, for others the rash can be extremely sore and itchy.
The skin condition attracted attention during the pandemic after mostly children and teenagers with COVID-19 developed the lesions.
To figure out what was causing the skin condition in some patients, the researchers studied 50 people with suspected “COVID toes” in the spring of 2020 as well as 13 other people with similar chilblains lesions that were unrelated to COVID-19 because they had the condition long before the pandemic.
According to their findings, the toe and finger lesions are the result of the body’s immune system going into overdrive to fight off an infection from the SARS-Cov-2 virus, which causes COVID-19.
More specifically, the study’s authors said there are two components of the immune system that are associated with the development of chilblain-like lesions in COVID-19 patients and in those who already had the condition.
One is an antiviral protein called type 1 interferon, and the other is a type of antibody called anti-neutrophil cytoplasmic antibodies that can mistakenly attack a person’s own cells and tissues during its efforts to fight off the invading virus.
Additionally, the researchers confirmed there was endothelial dysfunction in chilblain-like lesions. Endothelial dysfunction is a condition in which the endothelial layer (the inner lining) of the small arteries fails to perform all of its functions normally
“This study illustrates that both the immune system and endothelial cells play a critical role in the genesis of CLL (chilblain-like lesions),” the authors said.
While the lesions typically go away on their own, some patients may require treatment with creams and drugs.
In the study, the researchers suggest that local or systemic anti-inflammatory treatment could reverse the skin condition in COVID-19 patients.