1/
Okay #medtwitter and #dermtwitter, you knew it was only a matter of time, didn’t you?! Let’s do this #COVID19 themed #medthread:

#COVID TOES, a #TWEETORIAL!

#MedEd #FOAMEd #dermatology #dermatologia @AADskin @AADMember @Meddermsoc @dermhospitalist
2/
First, a word of caution – this is one person’s thoughts on a new skin finding reported in a new disease that the medical community is still learning about! As such, nothing in the #tweetorial should be regarded as definite. Just wanted to share a thought process!
3/
So, who cares? #COVID19 is devastating, at times even for the young & healthy! But it’s all respiratory, right?

Well, as we're learning, there's so much more to #SARScov2, and as a #dermatologist, this is the perfect example of how the exam helps frame possible mechanisms.
4/
And also, what if #covidtoes can help us with the testing and contact tracing effort?!

As @DrEstherFreeman & @lindyfox1 pointed out 👇, maybe #covidtoes are the new anosmia! Perhaps we should be testing even mild/asx patients with this finding! https://twitter.com/DrStevenTChen/status/1251273766996328448?s=20
5/
Now that I've hopefully made a case for why we should care, what’s actually happening underneath the skin?

There have been multiple reports and different clinical photos of #covidtoes.👇

PC: https://www.fip-ifp.org/wp-content/uploads/2020/04/acroischemia-ENG.pdf for pic1.

PC: https://www.today.com/health/skin-symptoms-related-coronavirus-doctors-discuss-covid-toes-t178991
6/
Importantly, these 2 photos make me think of 2 different processes!

The 1st photo looks like retiform purpura. This means that the purpura is stellate & makes me think that something is blocking blood flow. See my #tweetorial on purpura for details:

https://twitter.com/DrStevenTChen/status/1099828893656252416?s=20
7/
The 2nd doesn't look retiform, but it reminds me of perniosis/chilblains. Pernio is usually seen with cold/damp weather. On histology, there is inflammation/edema, and some reports of a lymphocytic vasculitis.

In kids, this can be assoc w/ cold agglutinins or cryos.
8/
So hang on to your seats while I conjecture wildly:
- Are these 2 photos showing the same process?
- Could one be more thombotic & the other more inflammatory?
- Why is it only distal? Is it embolic (doubt it) or temperature related?
- Could this elucidate any vascular issues?
9/
I would make a couple other points:

We already know that there is some thrombotic process with some cases of #COVID19. Perhaps #covidtoes are related to that. This paper found #SARS_CoV2 infected patients had viral inclusions in endothelial cells:

https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30937-5/fulltext
11/
I should point out that there have been a host of other skin eruptions reported with #COVID. I think many of them are nonspecific and may just be reflections of the immune system dealing with a viral process. #Covidtoes seem to be much more specific for this.

pc: @dermnetnz
12/12
Bottom line: If I see #covidtoes & I have the capability, I'd consider a #COVID19 test for the purposes of improving our testing/tracing effort.

A quick plug for the @AADskin #COVID registry. It'd be great to gather more data so we can learn more!

https://www.aad.org/member/practice/coronavirus/registry
You can follow @DrStevenTChen.
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