00:00
Okay. Next up, we're going to talk about Sarcoidosis. Here's our case. A 27-year-old refugee
from Rwanda who immigrated to the United States 6 months ago presents with cough and dyspnea.
00:15
He reports he used to play soccer recreationally, but now he finds himself getting fatigued
when walking one city block. He also noticed an intermittent non-productive cough increasing
over the past 3 months. He reports some subjective fevers and night sweats though he does not have a
thermometer at home. This is a pretty classic kind of presentation for sarcoidosis. He's a
non-smoker, no alcohol or illicit drugs. He now bags groceries while attending school here in the
US. Non-contributory family history, he has no rash, no eye symptoms, no GI symptoms, and no
joint pain. So let's take a look at some key features here. Sarcoidosis typically has 2 different
patterns of time when it can present. Someone in their 20s, that one pretty typical. And then
there's another peak later on in life in the 50s and 60s. Being from Rwanda, he's presumably of
African descent and dark skinned patients are much more likely to get sarcoidosis. There's a
much higher frequency at least 3:1 than amongst Caucasians. Cough and dyspnea, sarcoidosis
that is the most common presenting complaint and the presence of some constitutional features
with fevers and night sweats, this is all going for sarcoidosis. Especially the fact that it's been
going on for 3 months, it's more of an indolent subacute chronic course than something like
pneumonia which would present just over the span of a few days. Here's some data. Low-grade
temperature maybe 99.2, heart rate 72, blood pressure is fine, has no evidence of any scleral
involvement or lymphadenopathy. Okay. Regular rate and rhythm on a cardiovascular exam, pretty
unremarkable. Has dry crackles at the right upper lung field, no wheezing. There is full vesicular
breath sounds otherwise throughout. Abdomen is benign. Musculoskeletal benign. Skin and
nails, no findings. 90% of patients do present with pulmonary symptoms alone. So, it's not unusual
that he doesn't have anything going on for sarcoidosis except for the lung findings. The skin
and eye manifestations that we oftentimes associate with sarcoidosis actually only occur in
about 25% of patients at the time of presentation. So, we're still good. Let's get some more
data. Okay, so now we've got some data. Let's take a look. CBC, normal, alright. Basic metabolic
panel, normal creatinine. The calcium is normal. Now, while this calcium is normal keep in mind
that hypercalcemia which we oftentimes think of as sarcoidosis is only present in about 10% of
of patients. It turns out that the pulmonary granulomas, one of which is nicely portrayed in this
image, increase the production of 125 dihydroxy-vitamin D which is of course going to increase
the intestinal absorption of calcium and lead to hypercalcemia. Either way, we're not seeing it
and that's okay. Liver function tests, also normal. With sarcoid, you can oftentimes get a
cholestatic picture. The sarcoid granulomas are basically pushing on the biliary ducts within the
liver and can cause alk phos to rise up to this granulomatous infiltration which we're not seeing
here either. It's alright though, we're focusing on the pulmonary symptoms. The ACE level
there also normal and it's a test that we will often check when somebody is being considered
for sarcoidosis but it's actually only positive about 60% of the time. So, why you may see it on
the boards it's really not a particularly useful diagnostic test. In this case, it looks like the
money is really on that x-ray. We've got bilateral hilar lymphadenopathy, a subtle infiltrate in
the right upper lobe with calcifications. This is an absolutely classic chest x-ray finding for
sarcoid and certainly makes us lean towards that diagnosis. What's this, we have a PPD that's
positive to 18 mm and induced sputum for acid-fast bacilli is positive? This guy's got tuberculosis.
04:05
This isn't sarcoidosis at all. Well, now I actually knew that was going to happen but it's important
for us to always be mindful not only of the most common thing to consider when you're thinking
about sarcoid that is tuberculosis but also it's good to remind ourselves about anchoring bias.
04:21
This lecture is called sarcoidosis so our inclination is to leap right to that diagnosis, but things
aren't going to be that easy in all of these videos. So in this case, we can move on, we know
that this is actually a case of tuberculosis. This guy needs an ID consult and a negative air
pressure room.