Table 4. Examples of rare syndromes accompanied by eosinophilia.

Sydrome	Characteristics
Gleich’s syndrome	Cyclic recurrent angioedema and elevated IgM, sometimes with clonal T cells
Churg–Strauss syndrome	Necrotizing vasculitis with eosinophilia (ANCA+ and ANCA− subvariants)
Eosinophilia myalgia syndrome	Severe myalgia, often accompanied by neurologic symptoms and skin changes; epidemic cases have been attributed to l-tryptophan exposure (subvariant: toxic oil syndrome)
Omenn syndrome	Severe combined immunodeficiency plus HE, often with erythroderma, hepatosplenomegaly or lymphadenopathy, autosomal recessive genetic disease (recurrent mutations in RAG1 or RAG2)
Hyper-IgE syndrome	Hereditary immunodeficiency syndrome with HE and elevated levels of IgE, often with eczema and facial anomalies. Known gene mutations – autosomal dominant variant: STAT3 mutations; autosomal recessive variant: DOCK8 mutations

ANCA: Antineutrophil cytoplasmic antibodies; HE: Hypereosinophilia.