Allergic rhinitis is a reaction that happens in the eyes, nose and throat. It occurs when allergens in the air trigger the release of histamine and other chemicals in the body. Normally allergens are harmless. But when a person has allergies, the body thinks these allergens are harmful and attacks them. Special cells called mast cells release chemicals including histamine. The chemicals irritate nearby nasal tissue. This causes nasal allergy symptoms. When this happens in the lungs' breathing tubes, it can cause asthma symptoms such as coughing and wheezing.
Allergic rhinitis can happen on a seasonal basis or year-round. There is often a family history of allergic rhinitis, eczema, asthma or food allergy.