You know that granulomatosis with polyangiitis (née Wegener’s) causes lung disease, but did you know it also causes peripheral neuropathy? Keep in mind that “not all that wheezes is asthma.” Wheezing is a sign of obstructive lung disease, not a diagnostic feature, so consider asthma alternatives in adults. Hemoptysis and fever change the game.
Asthma, hemoptysis, neuropathic symptoms.
Low grade fever (B symptoms).
You know its a vasculitis.
Do ANCA. IgE testing is too nonspecific to yield any value and make a dx for u. despite churg strauss having both elevated igE and eosinophilia.
Took me long time but got it right. kinda lucky.
submitted by ∗mmizell(26)
Skipping the symptoms, I initially thought a1-antitrypsin because of the "adult-onset asthma/younger COPD," but the remainder of the symptoms don't fit and none of the answer choices are consistent with that. My next thought was also Wegener's v. Churg-Strauss v MPA, but I thought that all three could have peripheral neuropathy, and was quite thrown off by this question. I knew CS had elevated IgE levels and stupidly guessed that response.
However I think that the main goal of the question was to get you to figure out the first step in differentiating the three (as separate from other vasculitides), making the answer "serum ANCA-ab assay." Then evaluation for granulomas, then eosinophilia (neither of which were answers). Evidently IgE levels aren't necessary for diagnosis.
See Figure 2: https://www.aafp.org/afp/2002/0415/p1615.html