Allergic Rhinitis

The Facts

Allergic rhinitis literally means "allergic nose inflammation": rhino means "to do with the nose" and the ending -itis simply refers to inflammation. Seasonal allergic rhinitis is also commonly known as "hay fever."

This condition can either be seasonal or year-round. In most people, an allergen - something that triggers an allergy - sets their symptoms off at about the same time each year. Spring attacks are usually due to tree pollen, while grass pollens dominate in the summer and weed pollens in the autumn. Most people with allergic rhinitis are sensitive to more than one allergen.

Perennial allergic rhinitis appears year-round. This condition is most common in people with allergies to allergens that are present all year. Naturally, people who are allergic to house dust mites or to their own pets tend to suffer no matter the season.

Causes

Hay fever is an atopic or allergic disease like asthma, meaning that the body tends to overreact to certain types of outside substances. One way it overreacts is by releasing histamine, a chemical present in many important animal cells. Histamine is a major cause of the symptoms of hay fever including sneezing, runny nose, and even coughing. Hay fever, like asthma, can be inherited, but you probably don't inherit particular allergies, such as to cat dander or ragweed. Instead, you just inherit the tendency to be allergic. Children have a 30% chance of developing allergic rhinitis if one of their parents is affected and a 50% chance if both have allergic rhinitis.