The Facts
Allergic rhinitis, also called hay fever or pollinosis, literally means "allergic nose inflammation," where rhino means "to do with the nose" and the ending -itis simply refers to inflammation.
Allergic rhinitis 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. Allergic rhinitis affects about 17% to 25% of people in the United States.
Causes
Allergic rhinitis is an allergic condition like asthma, meaning that the body tends to overreact to certain types of outside substances. One way it overreacts is by producing antibodies that signal your immune system to release histamine and other chemicals. These chemicals cause the symptoms of allergic rhinitis including sneezing, runny nose, itchy or watery eyes, and even coughing.
Allergic rhinitis 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% to 60% chance of developing allergic rhinitis if one of their parents is affected and a 50% to 70% chance if both parents have allergic rhinitis.
