Churg-Strauss syndrome, also called allergic granulomatosis, is a vasculitis of medium-sized blood vessels, characterized by the triad of eosinophilia, pulmonary disease (e.g., asthma) and eczema. Renal disease also is a common part of the syndrome, as are granulomas outside the blood vessels. It was first described in 1951, within a population with the preliminary diagnosis of polyarteritis nodosa; the other patients had normal eosinophil counts.
Many patients are positive for antineutrophil cytoplasmic antibodies, and the mechanism of disease is thought to involve cytokines. Clinical support of the cytokine hypotnesis comes from the "therapeutic efficacy of recombinant interferon-alpha (IFN-alpha) and tumor necrosis factor-alpha (TNF-alpha) blockade. Recent data show that, in contrast to other primary systemic vasculitides, peripheral blood mononuclear cells (PBMCs) secrete not only large amounts of T helper type 1 (Th1) cytokines, particularly IFN-gamma, but also release T helper type 2 (Th2) cytokines such as interleukin-4 (IL-4) and interleukin-13 (IL-13). Interleukin-5 is the most potent stimulator of eosinophil production and functional activation of mature eosinophils." 
- Churg J, Strauss L. (1951), "Allergic granulomatosis, alletic angiitis, and periarteritis nodosa", Am J Pathol 27: 277
- Hellmich B, Csernok E, Gross WL (2005 June), "(Abstract) Proinflammatory cytokines and autoimmunity in Churg-Strauss syndrome.", Ann N Y Acad Sci 1051: 121-31.