Immunoglobulin E (IgE) is a class of antibody produced in the lungs, skin, and mucous membranes that has only been found in mammals. It plays an important role in allergy, and is especially associated with type 1 hypersensitivity. IgE has also been implicated in immune system responses to most parasitic worms like Schistosoma mansoni, Trichinella spiralis, and Fasciola hepatica, and may be important during immune defense against certain protozoan parasites such as Plasmodium falciparum. The antigen-specific IgE interacts with mast cells and eosinophils, triggers the release of histamine, leukotrienes and other substances that lead to the itching, sneezing and congestion of allergies - and the life threatening respiratory distress of asthma and anaphylactic shock.