Churg-Strauss syndrome (also known as allergic granulomatosis) is a form of vasculitis due to autoimmunity, leading to necrosis. It involves mainly the arteries, the lungs (it begins as a severe type of asthma), and nerves. Churg-Strauss syndrome is classified both as a type of polyarteritis nodosa and, more broadly, as a diffuse connective tissue disease.
Diagnostic markers include eosinophil granulocytes and granulomas in affected tissue and pANCA antibodies against neutrophil granulocytes. Differentiation from Wegener's granulomatosis can be difficult.