What are COVID toes?

The World Health Organization (WHO) lists skin rashes including discolouration of fingers or toes among the “less common symptoms” of COVID-19—the viral infection caused by severe acute respiratory syndrome coronavirus-2.

COVID toe seems to appear in younger patients more often than older ones. And it tends to appear alone—meaning it is usually the only symptom of COVID-19 in these patients.

While the rashes of COVID toe can appear like chilblains, there are some important differences:

• Chilblains occur due to inflammation in the small blood vessels when your skin exposed to cold but not freezing temperatures. COVID toe is not linked to ambient temperature or seasonal change. As the winter months approach in much of the northern hemisphere, it is important to keep this difference in mind.
• Chilblains are characterised by itchy and painful swelling, with inflammatory cells centred around the blood vessels and sweat glands in the toes and fingers. COVID toes may spread to the entire foot and fingers and may be accompanied by papules (small bumps) and blood clots (focal thrombi).

So by themselves, swollen or itchy toes may not be a sign of COVID-19. If you’ve never (or seldom) had chilblains in the wintertime in the past, and you don’t have a medical history or family history of lupus erythematosus, but you develop chilblains-like swelling in your toes and fingers during the pandemic, talk to your doctor for next steps.

Researchers have suggested that COVID-19 could last for several weeks after the infection has cleared up (post-COVID) and might be useful to study residual inflammation in the body in COVID long-haulers. Post-COVID is a term used to indicate the health problems that recovering COVID-19 patients face after they have been declared infection-free. (Read more: Post-COVID care: what to do for breathlessness and other common symptoms after the infection clears)

COVID toe is just one of the skin-based manifestations of COVID-19. Some other skin-based symptoms of COVID-19 are erythematous rash, widespread urticaria (hives), and chickenpox-like vesicles. Skin rashes may be accompanied by mouth rashes in COVID-19.

Skin symptoms of COVID-19 are rare: researchers say anywhere from 0.2% to 29% of patients get them (the wide range maybe because of inconsistent data collection across regions or different strains of the virus in different geographies). COVID toes are associated with milder, even otherwise asymptomatic, infection in younger people. The signs may include:

• Red rashes on toes that can spread to the feet and fingers
• Skin discolouration: the rashes may become purplish
• Petechiae: the appearance of red, purple or brown dots under the skin
• Swelling in affected toes and fingers
• Blisters
• Itchy bumps that can appear on the feet as well as chest and back
• Pain
• Itching
• Acro ischemic lesions or lesions at the tips of the toes and fingers

The exact cause of COVID toes is not known. It is, of course, associated with COVID-19 infection which has been known to cause inflammation in multiple organs of the body. Researchers have suggested that the drugs given to COVID-19 patients to fight off infection could also cause these skin symptoms.

Case studies show that COVID toes are linked with milder infection, and all in all, a good prognosis for patients. Having said that, researchers also think that these lesions could be infectious, and may continue to be infectious in the post-COVID phase. All precautions must be taken while attending to COVID toes.

COVID toes can last for 10-130 days, according to data collected in the US. Similar data for India is not yet available.

A doctor can diagnose COVID toes based on the symptoms you describe, a physical examination and a test for COVID-19 infection. He or she may also order some tests to rule out other conditions like chilblain lupus erythematosus.

Usually, COVID toes resolve on their own as the infection passes. If the itching (pruritis) and pain become too much for you, ask your doctor to prescribe a hydrocortisone ointment for it. Do not self medicate, as that can be harmful.