Allergic rhinitis Seasonal allergic rhinitis In hay fever (also called seasonal allergic rhinitis), the lining of the nose becomes inflamed due to an allergic reaction to pollen. In other types of allergic rhinitis, the allergic reaction occurs in response to other normally harmless substances (allergens), such as house dust mites, flakes of skin shed from animals (such as cats or dogs), or feathers.
The allergic reaction is due to an exaggerated response of the immune system that, when exposed to the allergen, produces histamine and other chemicals that cause inflammation and fluid production in the nose and sinuses.
This, in turn, produces symptoms such as a runny, stuffy, or itchy nose; sneezing; an itchy throat; and itchy, Symptoms of hay fever and allergic rhinitis can be prevented by avoiding the allergen, if possible. Medication may be used relieve the symptoms of hay fever and allergic rhinitis. In severe cases, immunotherapy may be an option.
This involves gradually introducing increasing amounts of the allergen into the body in order to desensitize the immune system