Asthma is triggered in several ways and most of them are not completely understood. Allergic Asthma Allergic asthma involves the body's immune system. This is a complex defense system that protects the body from harm caused by foreign substances or microbes. These are produced when the human body contacts an alien substance or microbe. Antibodies react with substances or microbes to destroy them.
Antibodies are often very selective, acting only on one particular substance or type of microbe.
But antibodies can also respond in a wrong way and cause allergic disorders such as asthma. When re-exposure occurs, the lung cells with attached IgE antibodies react with the substance. Leukotrienes provoke the contraction of some muscles in the airways. This causes the narrowing of air passages which is characteristic of asthma. Following repeated exposure to an industrial chemical, substances such as leukotrienes are released in the lungs.