Allergic rhinitis Allergic rhinitis , also known as hay fever, is a type of inflammation in the nose which occurs when the immune system overreacts to allergens in the air. Signs and symptoms include a runny or stuffy nose, sneezing, red, itchy, and watery eyes, and swelling around the eyes. Causes : When your body comes into contact with an allergen, it releases histamine, which is a natural chemical that defends your body from the allergen. This chemical can cause allergic rhinitis and its symptoms, including a runny nose, sneezing, and itchy eyes. In addition to tree pollen, other common allergens include: grass pollen dust mites animal dander, which is old skin cat saliva mold During certain times of the year, pollen can be especially problematic. Tree and flower pollens are more common in the spring. Grasses and weeds produce more pollen in the summer and fall. Symptom: Common symptoms of allergic rhinitis include: sneezing a runny nose a stuffy nose an itchy nose coughing a