If you have allergic rhinitis, your immune system mistakenly identifies a typically harmless substance as an intruder. This substance is called an allergen. The immune system responds to the allergen by releasing histamine and chemicals that typically cause symptoms in the nose, throat, eyes, ears, skin and roof of the mouth. Seasonal allergic rhinitis (hay fever) is most often caused by pollen carried in the air during different times of the year in different parts of the country. A person can develop allergic rhinitis at any age. Perennial rhinitis can be caused by dust, pet hair or molds. Allergy tests can identify a person’s sensitivities and guide the approach to treatment.

Chronic sinusitis is a common condition in which the cavities around nasal passages (sinuses) become inflamed and swollen for at least 12 weeks, despite treatment attempts.
Also known as chronic rhinosinusitis, this condition interferes with drainage and causes mucus buildup. Breathing through the nose might be difficult. There might be facial pain or tenderness. Chronic sinusitis can be brought on by an infection, by growths in the sinuses (nasal polyps) or by a deviated nasal septum. The condition most commonly affects young and middle-aged adults, but it can also affect children.

Non-allergic rhinitis involves chronic sneezing or a congested, drippy nose with no apparent cause. The symptoms of non-allergic rhinitis are similar to those of hay fever (allergic rhinitis), but no evidence of an allergic reaction is present, and tests are negative for allergies. Non-allergic rhinitis can affect children and adults. Triggers of non-allergic rhinitis symptoms vary and can include odors or irritants in the air, weather changes, some medications, certain foods, and chronic health conditions. A diagnosis of non-allergic rhinitis is made after an allergic cause is ruled out. This may require skin or blood tests.