Gleich's syndrome or episodic angioedema with eosinophilia is a rare disease in which the body swells up episodically (angioedema), associated with raised antibodies of the IgM type and increased numbers of eosinophil granulocytes, a type of white blood cells, in the blood (eosinophilia). It was first described in 1984.
Its cause is unknown, but it is unrelated to capillary leak syndrome (which may cause similar swelling episodes) and eosinophilia-myalgia syndrome (which features eosinophilia but alternative symptoms). Moreover, it is not a form of hypereosinophilic syndrome as there is no evidence that it leads to organ damage. Some studies have shown that edema attacks are associated with degranulation (release of enzymes and mediators from eosinophils), and others have demonstrated antibodies against endothelium (cells lining blood vessels) in the condition.
Gleich syndrome has a good prognosis. Attack severity may improve with steroid treatment.