Covid toes: a new virus symptom to look out for

Just when we thought life couldn’t get any more bizarre, Covid-19 toes became a thing. We know it is one of the newest Covid-19 symptoms to be reported and that it affects the feet, but what exactly is it?

Manifesting as red sores or purple-looking toes and swollen feet, Covid-19 toes appear to be similar to chilblains, which is a painful condition caused by inflamed blood vessels in the skin as a result of exposure to cold air. The symptoms of chilblains include red patches, itching, blistering and swelling on the hands and feet.

The difference with Covid-19 toes, however, is that it has affected people in both cold and relatively warm climates.

Covid-19 toes have caused some controversy. Doctors first picked up on the phenomenon in April, when they started observing symptoms predominantly in younger patients who were relatively healthy and showed no or very few symptoms of Covid-19.

Experts were unsure whether the increase in patients exhibiting these signs were related to Covid-19, but an editor’s note published in the journal JAMA Dermatology at the end of June suggested the two are related, and urged dermatologists to be aware of a possible link.

The authors, Dr Claudia Hernandez and Dr Anna Bruckner, both dermatologists in the US, referred to two studies that had been conducted. In both studies, none of the patients who exhibited symptoms of Covid-19 toes tested positive for Covid-19 or showed any symptoms. The authors in both studies suggested that lifestyle changes related to lockdown, such as being less active and walking barefoot on cold surfaces, could be to blame for these symptoms.

A study published in the British Journal of Dermatology, also in June, contained similar findings.

Seven children with symptoms of Covid-19 toes were tested for Covid-19 using throat swabs or by testing for antibodies, but all tested negative for the coronavirus. However, after conducting skin biopsies on the children, the researchers found traces of Covid-19 in the blood vessels of the children’s skin, endothelial cells surrounding the blood vessels and sweat glands.

In cases where symptoms of Covid-19 toes have coincided with symptoms of Covid-19, it appeared this has happened after the patient was initially infected.

The results of a study conducted by dermatologists in Madrid, Spain, that was published this month found that affected patients developed symptoms of Covid-19 toes and skin lesions on average nine days after first starting to exhibit Covid-19 symptoms.

Despite the initial controversy around whether Covid-19 toes are an official symptom of Covid-19, on its website the World Health Organisation lists “a rash on skin, or discolouration of fingers or toes” under the list of less common Covid-19 symptoms.

Other less common symptoms include diarrhoea, conjunctivitis (or pink eye) and a loss of taste or smell.