what causes the inflammation of nasal mucosa that is seen in allergic rhinitis?
Viruses, bacteria, allergens, and irritants can cause inflammation of the nasal mucous membranes, which results in rhinitis. Once inflamed, the nose produces excessive mucus, which causes a runny nose, nasal congestion, and postnasal drip (when mucus drips from the sinuses, down the throat). Allergic rhinitis is one of the most common allergies.