Small vessel vasculitis question

[Phloston]

From GT:

"A 44-year old male comes to your office because of worsening paresthesias in his hands and feet and now he has recently developed some intermittent hemoptysis. He had a recent pneumonia for which he was treated with an antibiotic, the name of which he does not remember. He admits to feeling tired and has lost some weight but denies any abdominal pain or discomfort. Review of systems is positive for some new rash. Vitals are normal except an elevated blood pressure. Physical exam shows palpable purpura of the lower extremities. What is the most likely diagnosis?

A. Henoch-Schonlein Purpura
B. Wegener's granulomatosis
C. Churg-Strauss syndrome
D. Microscopic polyangiitis
E. Polyarteritis nodosa"


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The answer is D.

Now before anyone goes jumping out and saying why it's not the other answer choices (i.e. I'm very aware of the Sx of the other answer choices), I'm curious to know simply why the vignette specifically supports microscopic polyangiitis. In other words, why should this Dx have jumped out at me other than simply inferring that the presentation wasn't the others?

Cheers,

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[AndyRSC]

My personal path notes read:

"Microscopic polyangiitis (p-ANCA): basically Wegener's without granulomas."

Clearly I didn't expect to see a question on this in my lifetime.

 

[Phloston]

The only thing I've really been able to gather is that the palpable purpura are notable in microscopic polyangiitis, much more than in Wegener's. Also, HSP occurs in younger pts, so that could be ruled out.

So if I had to see a vignette in the future that were microscopic polyangiitis, I would make sure palpable purpura were there and that the age were not paediatric.

Then I would look to eliminate Wegener's, CS, PN based on the lack of notable findings associated with those.

 

[lstone13]

Only things I can think of in addition to what you already said... The fact that it was preceded by an infection and by an antibiotic. According to Rapid Review Pathology, microscopic polyangiitis can be precipitated by drugs (Penicillin), infections (Streptococci), and immune disorders (SLE). Also, the paresthesia seems to be indicative of it as well. Apparently, nerve damage is common manifestation of MPA.

 

[Phloston]

Only things I can think of in addition to what you already said... The fact that it was preceded by an infection and by an antibiotic. According to Rapid Review Pathology, microscopic polyangiitis can be precipitated by drugs (Penicillin), infections (Streptococci), and immune disorders (SLE). Also, the paresthesia seems to be indicative of it as well. Apparently, nerve damage is common manifestation of MPA.

Thanks for that. Yeah, the neural effects are also seen in CS, but the infection-/drug-induced precipitation is great to point out.

 

[OveractiveBrain]

From GT:

"A 44-year old male comes to your office because of worsening paresthesias in his hands and feet

Loosely Mononeuritis Multiplex, which is nonspecific for any vasculitis, usually small vessel = small vessel

and now he has recently developed some intermittent hemoptysis.

Hemoptysis (yay!) we're looking for hemoptysis and Hematuria

He had a recent pneumonia for which he was treated with an antibiotic, the name of which he does not remember.

Very weak, very. MAYBE (like above poster) set up based on antibiotics / infection. MAYBE. Though URI/PNA you think Henoch-Schlonein purpura.

He admits to feeling tired and has lost some weight but denies any abdominal pain or discomfort.

Says "rheumatologic" and may have a vasculitis. Absence of abd pain is saying "not PAN"

Review of systems is positive for some new rash. Physical exam shows
palpable purpura of the lower extremities.

Says small vessel vasculitis. Great, thats every option choice except PAN

Vitals are normal except an elevated blood pressure. What is the most likely diagnosis?

Extremely indirectly, says "renal damage" so I guess, I GUESS...

You've got Hemoptysis + Renal Damage + Small Vessel Vasculitis. Not very specific for the diagnosis they've chosen, and quite frankly a crap question. I think you were supposed to go by ruling out the others...


A. Henoch-Schonlein Purpura: (this also fits, alot, given URI/PNA)... doesn't have the age or location or rash
B. Wegener's granulomatosis: no mention of sinus involvement or hematuria
C. Churg-Strauss syndrome: no mention of eosinophilia
D. Microscopic polyangiitis: whew, really, this is the answer?
E. Polyarteritis nodosa: medium vessel vasculitis that does not fit in any way with what they're describing

 

[Tarasaurusrex]

From GT:

"A 44-year old male comes to your office because of worsening paresthesias in his hands and feet and now he has recently developed some intermittent hemoptysis. He had a recent pneumonia for which he was treated with an antibiotic, the name of which he does not remember. He admits to feeling tired and has lost some weight but denies any abdominal pain or discomfort. Review of systems is positive for some new rash. Vitals are normal except an elevated blood pressure. Physical exam shows palpable purpura of the lower extremities. What is the most likely diagnosis?

A. Henoch-Schonlein Purpura
B. Wegener's granulomatosis
C. Churg-Strauss syndrome
D. Microscopic polyangiitis - this is avasculitic syndrome, other vasculitic syndromes include B and C. This DX is often a differential DX for vasculitic syndromes. It most likely "jumped out" at you because it is very broad and since tests haven't been done on the patient the type of vasculitic syndrome they suffer from wouldn't yet be classified. Wegener's and Churg-Strauss are more specific DX's and polyarteritis nodosa doesn't have the same physical symptoms, but includes a lot of other symptoms that weren't mentioned.
E. Polyarteritis nodosa"

I am going out on a limb here though and say I think it could be A. Why? Well A isn't restricted to children, just more common in children and if that's the sole reason for discounting it, I think it's a bit weak. The specific symptoms point to A. Such as the elevated BP and placement of the purpuras. Also, it's important to ask if the patient is on Warfarin, because that could possibly establish a heart condition that caused elevated BP. Also using it puts patients at risk for vasculitic diseases (Along with plenty of other things). What do you think? I know the answer is D, but I think they needed to present another symptom besides age, to completely negate the possibility of A.

------

The answer is D.

Now before anyone goes jumping out and saying why it's not the other answer choices (i.e. I'm very aware of the Sx of the other answer choices), I'm curious to know simply why the vignette specifically supports microscopic polyangiitis. In other words, why should this Dx have jumped out at me other than simply inferring that the presentation wasn't the others?

 

[Phloston]

Absence of abd pain is saying "not PAN"

Interesting that you mention no abdominal pain as the basis for "not PAN." I would think the haemoptysis alone would be enough to rule it out, considering PAN spares the pulmonary vasculature.

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I've basically annotated into my FA (something along the lines of) that Sx which don't quite fit PAN, Wegener's or CS, in combination with notable palpable purpura, point toward HSP or MP. If the patient is paediatric and had just had a viral infection, HSP is the better differential, however, IgA nephropathy is commonly associated with HSP, and if the patient doesn't have haematuria (as with this vignette), HSP is less likely. MP can be precipitated by drugs, so a bacterial pneumonia that's treated successfully points toward MP, whereas a mere viral infection that's untreated --> HSP.

In other words, this question teaches that microscopic polyangiitis is a diagnosis of exclusion. Sx that don't point quite fit the other pathologies throw this one higher onto the differential.

 

[just one]

Having done uworld and taken step 1 recently, I've concluded from all your posts gunner training questions are absolutly worthless (at least for me, my prep, and my actual step 1 exam)

 

[Phloston]

Having done uworld and taken step 1 recently, I've concluded from all your posts gunner training questions are absolutly worthless (at least for me, my prep, and my actual step 1 exam)

Lol. Some of the GT questions are definitely bad, I agree.

However, I'm only posting genuinely bad ones, if any, and that's about ~3-4 per 50-question block. I'd actually say that's on par with USMLE Rx's bad question rate as well, but I hadn't posted about those because the explanations were better.

I would only recommend GT QBank Qs if you've already finished Rx and want additional annotation-power before going on to Kaplan or UWorld. Just as Rx is great for reinforcing FA, I've noticed that, despite GT's Qs being crappy at times, GT definitely helps reinforce some of the super-particular details in FA that even Rx doesn't assess.

 

[JackShephard MD]

Lol. Some of the GT questions are definitely bad, I agree.

However, I'm only posting genuinely bad ones, if any, and that's about ~3-4 per 50-question block. I'd actually say that's on par with USMLE Rx's bad question rate as well, but I hadn't posted about those because the explanations were better.

I would only recommend GT QBank Qs if you've already finished Rx and want additional annotation-power before going on to Kaplan or UWorld. Just as Rx is great for reinforcing FA, I've noticed that, despite GT's Qs being crappy at times, GT definitely helps reinforce some of the super-particular details in FA that even Rx doesn't assess.

Since you are the qbank/qbook king, I'd love to hear a bit more about GT qbank quality. I've never used the questions and most of the users who use the flashcards do not actually use the qbank. Would you say, other than these few Q's that it's a pretty solid question bank?

Since you've had experience with Kaplan, Usmlerx, and also their question books (kaplan/FA qbook), where would you rank GT among them?

 

[Phloston]

Since you are the qbank/qbook king, I'd love to hear a bit more about GT qbank quality. I've never used the questions and most of the users who use the flashcards do not actually use the qbank. Would you say, other than these few Q's that it's a pretty solid question bank?

Since you've had experience with Kaplan, Usmlerx, and also their question books (kaplan/FA qbook), where would you rank GT among them?

I have not yet touched Kaplan QBank or UWorld. I've only done University of Utah Webpath, Robbin's Review of Path, USMLE Rx, Kaplan QBook, FA Q&A and ~2000 of the ~2650 GT QBank Qs.

In terms of raw, absolute quality of the GT Qs with respect to the USMLE-style format, they are not very good. Many of them are merely one- or two-liners, and the explanations are very poor. However, many of the questions that are asked hit areas where I'd literally be like, "wow, I can't believe I skipped over that detail in FA," or "that seems like a ridiculously low-yield question; they must be kidding," and then I'd flip to FA and the detail would be right there, and it wouldn't be an obvious one either.

I believe the true value of the GT QBank Qs doesn't fall in the category of learning the "trickery" or multi-step thinking required for the USMLE. The strength is merely in the fact that many of the Qs pick out small details in FA that I absolutely would have overlooked otherwise. I've definitely gained a few points from having gone through these Qs so far. I'll look to give them a fast second-pass closer to the exam.

Rx and GT QBank Qs have helped reinforce FA big time.

I hate to break out this analogy, but I'm starting to realize that QBank/book Qs are like friends. All relationships have different types of advice/input to offer and/or reciprocate, but not any one person has all of the characteristics we look for.

 

[JackShephard MD]

I have not yet touched Kaplan QBank or UWorld. I've only done University of Utah Webpath, Robbin's Review of Path, USMLE Rx, Kaplan QBook, FA Q&A and ~2000 of the ~2650 GT QBank Qs.

In terms of raw, absolute quality of the GT Qs with respect to the USMLE-style format, they are not very good. Many of them are merely one- or two-liners, and the explanations are very poor. However, many of the questions that are asked hit areas where I'd literally be like, "wow, I can't believe I skipped over that detail in FA," or "that seems like a ridiculously low-yield question; they must be kidding," and then I'd flip to FA and the detail would be right there, and it wouldn't be an obvious one either.

I believe the true value of the GT QBank Qs doesn't fall in the category of learning the "trickery" or multi-step thinking required for the USMLE. The strength is merely in the fact that many of the Qs pick out small details in FA that I absolutely would have overlooked otherwise. I've definitely gained a few points from having gone through these Qs so far. I'll look to give them a fast second-pass closer to the exam.

Rx and GT QBank Qs have helped reinforce FA big time.

I hate to break out this analogy, but I'm starting to realize that QBank/book Qs are like friends. All relationships have different types of advice/input to offer and/or reciprocate, but not any one person has all of the characteristics we look for.

Thanks for the detailed response. I think your strategy of doing massive questions is probably one of the better plans (alongside repetition and thorough review, of course).

 

[Phloston]

Thanks for the detailed response. I think your strategy of doing massive questions is probably one of the better plans (alongside repetition and thorough review, of course).

Jack, on the note of doing "massive" questions, I just thought I'd throw in the short story that I'm home at the moment for my sister having been married last weekend, and I went out last night and ran into one my HS friends whom I haven't seen since we were in AP chemistry together. Anyway, he just started MS4, and the topic of the USMLE came up (which is ridiculously normal when I'm part of any conversation), and he had said that he and one of his friends had studied quite a bit together and had gotten mid-high-250s. So I said, "okay, cutting to the chase, what did you do? [I already know] Questions." And he just looked at me and said, "Questions."

 

[loveoforganic]

This is how I imagine that conversation happened in your mind

 

[Phloston]

Lol. Loveoforganic, I'm amazed that someone would even design that artwork. I'm also even more amazed that you had come across that..

 

[adagio]

2 days before ABIM and i am back to googling questions like step 1
great discussion guys. Fast forward 3 years after.