What are "antihistamines"?

What are "antihistamines"?

Harold Kaiser (Practicing Allergist and Clinical Professor of Medicine, University of Minnesota Medical School) gives expert video advice on: What kind of medications are used to treat allergies?; Does using an EpiPen hurt? and more...

Antihistamines are medication which blocks histamine. Histamine is the chemical which is one of the most common chemicals that cause the allergic reaction. For example: If I'm allergic to dust and I inhaled some dust then my body will send signals and start a series of events. A cascade of events wherein white blood cells of the body will release certain chemicals. Among these chemicals are histamine, glucotrines, bradykirin, chemokines and the like. Histamines are chemical which cause the allergic reaction in the body.