Thread by @YaleIDFellows

It's the weekend, which means it is an excellent time to learn some #infectiousdiseases #IDboardreview:
A woman with a bioprosthetic valve p/w with a lower extremity rash x 4 months. Nephrotic range proteinuria and looking at the urine showed dymorphic RBCs. Rash as below:

What is the most likely cause of her syndrome?

The patient had a prosthetic valve endocarditis from Cardiobacterium hominis. Renal biopsy showed IgM 2-3+, IgA 2+, C3 2-3+, c1q 1+; and the cryoglobulins were equivocal. Alright so a brief #tweetorial on #endocarditis

Though we don't break infective endocarditis (IE) into acute/subacute/chronic so much any more (now we go more by organism and valve), it can be helpful to refresh some of the 'subacute' bacterial endocarditis symptoms (which we see less often now because of... antibiotics)

IE was famously first summarized way by Osler in the Gulstonian Lectures, 1885 , (ncbi.nlm.nih.gov/pmc/articles/P…) and then in 1909 came the description of chronic IE academic.oup.com/qjmed/article/…. Take a read of the OG if yo have a sec,

Here are descriptions of the skin finding from that article

Also, patients with IE have circulating immune complexes, as shown in this oldie but at goodie from @NEJM showing 97% of patient with IE had positive immune complex assays and this was higher than patients with sepsis or with control group nejm.org/doi/10.1056/NE…

These immune complexes were more likely to occur with extravalvular signs, symptoms longer than 4 weeks, right sided IE or hypocomplementemia or moderate to severe valvular involvement

As for this skin: though not one of your classic Janeway or Osler’s or even a splinter hemorrhages or sub-conjunctival hemorrhages, purpura are actually found in 8% of IE cases, which is the MOST COMMON skin manifestation of IE as per this jamanetwork.com/journals/jamad… from @JAMADerm

And last learning point of the case: not all prosthetic valves are the same. The Meolody valve is nice as it is a bio-prosthetic and can be placed percutaneously BUT there is a right risk of IE, between 3.2% to 25.0% as per this systematic review ahajournals.org/doi/full/10.11…

And that's it! Thank you @gandhisk for an informative case! Major teaching points:
- purpura can be a common but not specific skin finding of IE
- immune complexes can occur in patients with IE, especially if the IE is long standing
- prosthetic vales have more risk for IE

#endocarditis is a classic, what other cool things did I miss @DrJuthani @id_seval @maricar_malinis @MedTweetorials @VisualDx #IDmeded

Oh sorry, the image from the first tweet is from heart.bmj.com/content/95/2/1… :)