- Last Update On : 2013-01-20
IgE is one of the 5 classes (isotypes) of antibodies. Like other immunoglobulins, it is produced by B cells and plasma cells. In contrast to other immunoglobulins, the circulating concentration of IgE is very low because B cells synthesize it at a very low rate and mast cells, basophils, and activated eosinophils bind up most of the circulating IgE. The normal concentration of IgE is only 0.05% of the IgG concentration.
In industrialized countries, allergy is the most common cause of elevated IgE concentrations, whereas in lesser-developed agrarian countries, parasitic infection is the most common etiology. The differential diagnosis of elevated IgE is summarized in the following table.
Eczema, rhinitis, asthma, drug allergies, urticaria, extri