What Is Perniosis?

You might know perniosis by its more common name: chilblains. Although it generally appears as lesions on the skin, it is actually a type of vasculitis (an inflammation of the small blood vessels). It happens when skin is repeatedly exposed to humid air at temperatures between 0 °C and 16 °C, especially when this exposure is followed by rewarming.

This is an abnormal bodily reaction to temperature changes and its underlying cause is unknown. Risk factors include autoimmune disorders, particularly lupus; circulatory disorders, such as Raynaud’s disease; being underweight; and wearing unsuitable clothing for the weather conditions (no gloves, unsuitable shoes, tight clothing).

Perniosis has the appearance of lesions in the form of itchy or burning bluish-red patches and swelling. It is most commonly seen on the hands, toes, ears, nose, and cheeks, but can appear on calves, thighs, buttocks, and other areas. It doesn’t appear immediately after exposure to cold, damp air, but generally hours to a day after the return to warmer temperatures.

Is Perniosis Reversible?

While freezing air can cause permanent damage, perniosis is generally reversible provided there is no blistering or infection. In most people, the lesions will improve after one or two weeks of avoiding exposure to cold-and-rewarming cycles. Some patients benefit from hydrocortisone for the itching or burning sensation, and of course if an infection sets in, that will need to be dealt with.

If there are signs that they’re not healing, seek medical support. Note that diabetes and poor circulation can complicate the healing process. If you know you have either of these conditions, seek medical support after the lesions appear.

What Does Perniosis Have to Do with COVID-19?

Perniosis is not a symptom of COVID-19. However, during the pandemic, some patients have presented with pernio-like lesions on their toes. Deemed COVID toes in the popular press, the lesions are bluish-red and associated with swelling. It has been seen on people of any age but is particularly common in younger patients with no or mild other symptoms.

As with perniosis, COVID toes are generally not dangerous, but they have been seen to last months, worsen with blisters forming, and have the potential for infection. More commonly, they last up to two weeks.

But Are the Lesions Definitely Connected with COVID-19?

A recent study of 21 people with COVID toes suggested that there was no direct relationship between the SARS-CoV-2 virus and these pernio-like lesions, even going as far as to suggest that these were simply perniosis. The cohort wasn’t large enough to say those results are statistically significant, but it is interesting to note that there are divided opinions on COVID toes. Other studies are ongoing, some concluding that there is a direct relationship.

One interesting report is “Vaccine Toes Are the New COVID Toes”. It deals with a case of a person in their 60s who developed pernio-like lesions on their toes around a week after receiving their second dose of the Pfizer-BioNTech COVID-19 mRNA vaccine. The lesions cleared up within 6 weeks. The report also refers to 9 other vaccine-associated pernio-like lesions mentioned in the literature and posits that the lesions have a relationship to the immune system response to the vaccine.

How Common Are “Vaccine Toes”?

As “Vaccine Toes Are the New COVID Toes” points out, there have not been many cases of pernio-like lesions occurring after vaccination. Therefore, it should not be considered a common vaccine response and people should not be reluctant to take the vaccine because of them. Media outlets may be interested in reporting the story, because it relates to COVID-19, and physicians should be aware that patients may express concerns over “vaccine toes” and assuage their fears.

Note: This post is based on an article that is not open access, i.e., only the abstract is freely available.