*Such as dysplastic eosinophils, circulating myeloid precursors, anemia, thrombocytopenia, splenomegaly, elevated serum B12 and/or tryptase levels, atypical mast cells, hypercellular marrow, and myelofibrosis.

^†Episodic angioedema and eosinophilia is a distinct clinical syndrome characterized by multineage cycling and symptoms that occur at fixed intervals, an aberrant CD3-CD4⁺ T cell population, and elevated serum IgM.