[ad_1]
A mysterious condition known as “COVID toes” may finally have an explanation.
It turns out that frostbite-like rashes that appear on a person’s toes after catching COVID-19 may be a sign of an out of control immune response in which the body attacks its own tissues, according to a new study .
Cases of COVID toes began to occur at the start of the pandemic, and at the time, scientists had some ideas as to why the disease manifested itself, Previously reported live science. For example, some dermatologists have suggested that the witness skin sores and bumps, called pernio or frostbite, were caused by inflammation; others thought they could be the result of small blood clots in the toes.
Other viral diseases, such as measles, can cause rashes, so it wasn’t necessarily surprising that COVID-19 could, too. But now the results of a new study, published Oct. 5 in the British Journal of Dermatology, indicates why red-purple papules appear on the toes and sometimes the fingers.
Related: 20 of the worst epidemics and pandemics in history
For the new study, the team recruited 50 patients who were referred to the dermatology department at Saint-Louis Hospital in Paris after developing lesions resembling frostbite for the first time; all patients were admitted in April 2020, near the start of the pandemic.
The researchers found that most of their study participants had high levels of autoantibodies, proteins generated by immune system that inadvertently attack the body’s own tissues. They also found evidence that, compared to healthy individuals, the participants showed rampant activity of proteins called type 1 interferons, which turn on pathogen-fighting genes in immune cells. Although these interferons help fight viruses, human cells can end up suffering collateral damage in the process.
Study participants also showed signs that the lining of their some blood the vessels had been damaged, which may also have contributed to the appearance of purple rashes on their toes, the authors noted.
These results are consistent with those of a very small study published in 2020 in the journal Dermatopathology, The New York Times reported. The study only included three patients, but it hinted that the trio developed a rash on their toes due to a strong immune response induced by interferon. This inflamed immune response could help ward off the coronavirus, but it may also have resulted in persistent rashes, the authors suggested in their report.
At the time of the study, nearly 60% of patients had symptoms consistent with mild COVID-19, such as loss of smell or coughing, but all were negative for the virus on a PCR test. In general, COVID toes typically appear one to four weeks after a person has contracted SARS-CoV-2, the virus that causes COVID-19, and the rash can sometimes persist for months. The keeper reported. So it’s no surprise that someone is testing negative for COVID-19 despite having COVID-related rashes on their feet, given that the rashes could appear after the virus has been cleared from their system.
(For background, all three participants in the 2020 dermatopathology study also tested negative for COVID-19 at the time of research.)
Besides the coronavirus, other triggers of frostbite include diseases like lupus, that none of the study participants had; and exposure to cold, which would be unlikely in the spring, the authors note in their report. As cases of frostbite-like rashes ebbed and flowed with the waves of COVID-19 in 2020, overall, the available clues suggest that their patients’ rashes were linked to infection with COVID-19, the authors wrote in their report.
The team collected blood samples and skin biopsies from the patients and examined them for various signs of immune system activation. They also compared those samples to samples taken from healthy individuals and people who suffered seasonal frostbite, caused by cold, before the pandemic.
They found a significant overlap in the results of patients with suspected COVID and seasonal frozen patients, in that both carried autoantibodies and showed signs of increased type I interferon activity. suggests that the conditions stem from the common mechanism of an uncontrolled immune response, although the immune response itself is triggered by a different trigger in each scenario, the authors wrote.
Podiatrist Dr Ivan Bristow told The Guardian that for most people, COVID toes eventually go away on their own, without the need for medication. That said, for those whose rashes are slow to heal, the new study may point to helpful treatments, he said. For example, depending on the study results, local or systemic anti-inflammatory agents, such as steroids, may be effective in treating COVID toes, The New York Times reported.
Originally posted on Live Science.
[ad_2]
Source link