Snapshot A 34-year-old man presents to his doctor’s office for a rash of several weeks. He reports also having allergic rhinitis in the past few weeks, which was strange given that he normally has allergic rhinitis in the spring. Additionally, he reports having had childhood asthma, but in the past few months, he has had to use his inhaler for episodes of asthma. On physical exam, there is palpable purpura and urticarial plaques on the lower extremities and several skin nodules. Wheezes are heard on lung exam. Additional laboratory tests reveal peripheral eosinophilia with elevated IgE levels. (Eosinophilic granulomatosis with polyangiitis) Introduction Clinical definition login to view 2 more bullets Pathogenesis login to view 6 more bullets Studies login to view 2 more bullets Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss Syndrome) Clinical definition login to view 1 more bullet Presentation login to view 14 more bullets Studies login to view 8 more bullets Treatment login to view 2 more bullets Granulomatosis with Polyangiitis (Wegener Granulomatosis) Clinical definition login to view 1 more bullet Presentation login to view 15 more bullets Studies and imaging login to view 11 more bullets Treatment login to view 3 more bullets Microscopic Polyangiitis Clinical definition login to view 1 more bullet Presentation login to view 9 more bullets Studies login to view 8 more bullets Treatment login to view 2 more bullets