



WARNING! This may not be the COVID Toes article you want to read. But, if you still find it interesting or thought provoking, please do SHARE. I admit that some people took away from this article (and from the video below) that I do not think the prevalent toe manifestations being reported are associated with COVID-19. Well, that was NOT my intent. My intent was just to point out similarities to other well known vascular pathologies (e.g. Pernio/Chilblains etc.) and to call for more data to be collected. I would LOVE your COMMENTS and I promise to respond to any respectful discussion! Also, please note, this article is “live”. That means I am updating it as information comes my way. And now, onward! To the article!

Some doctors are noticing skin lesions in COVID-19 patients. There is specific interest regarding skin lesions on the toes of patients who are positive for COVID-19. They are calling this finding “COVID toes”. This has found its way to the general media like here or here. But, is the name appropriate? Can we use it to diagnose COVID-19 in otherwise asymptomatic patients? Or, is this a marker of past infection? Is it specific enough?

What do we need to understand COVID toes better?

The bottom line is we need more data. I am definitely in-tune with many of my colleagues who are seeing this in association with COVID-19. I am not saying otherwise. But I want to know more. What is the typical timeline? Does this occur with the diagnosis of COVID-19 or afterward? What is the mechanism? Is it inflammation? Are there thrombi? Both? Here are a few things to be on the lookout for:

Pernio sometimes lingers, but does not in most. Whether these lesions remain prevalent during warmer months will be revealing. And yes, I am aware that doctors are reporting this phenomenon in warmer climates (e.g. Italy).

Will we be able to find a mechanism? For example, are virus particles found in these lesions? Can we obtain proof of obstructed blood flow? Can we implicate inflammation? Interferone-1? Pathological studies are starting to emerge. Here is one example. Pathology showed ischemic epidermal changes, superficial and deep perivascular infiltrates and luminal thrombi. As a reminder, in Pernio, we see peri-vascular inflammation with lymphocytes as well. There seems to be much similarity.

Will we be reading about any unique findings in these lesions? Will they turn out to be different (in appearance, symptoms or natural history) compared to Pernio?

Are these toes COVID toes?

If I showed you this picture in the Fall or in the Winter, what would your diagnosis be?

I would probably say this was pernio. If the history fit, I might say it was Adderall induced vascular disease. In the ICU, this may fit purpura fulminance, an effect of pressors or embolic phenomena, among other options. Acrocyanosis can fit the bill as well. Basically, we need to consider the differential diagnosis of blue toes.

The COVID-19 pandemic started during the late fall of 2019 and spread throughout the winter. These are also the months when Pernio manifests. It is not unusual to see Pernio, especially in the North-Eastern United States. Therefore, calling these findings COVID toes may be premature. Maybe a better term should be ‘Pernio secondary to a viral infection’. Again, I realize clinicians in warmer climates are describing this. All I am saying is that it looks and behaves like Pernio, as far as I can tell. Also, some of the descriptions are coming from the ICU. So, in the end, COVID toes may actually be a mixed sack.

So, What Now?

At the time of first writing this short post, I could not find any literature specific to COVID toes. Then, a publication came out in the International Journal of Dermatology. It was a case report. No mechanism was offered. I have been encountering *many* passionate clinicians and patients. They all feel this is a real phenomenon. They feel that this is separate than other known entities. I hope to remember to update again once new literature is available, and I ask that you please alert me to any new information in the COMMENTS section.