Other causes in this category include nasal tumors and foreign bodies. Children are prone to inserting various objects such as peas, beans, cherry pits, beads, buttons, safety pins, and bits of plastic toys into their noses. Beware of one-sided foul smelling discharge, which can be caused by a foreign body. A physician should be consulted. Allergy is an exaggerated inflammatory response to a foreign substance which, in the case of a stuffy nose, is usually a pollen, mold, animal dander, or some element in house dust.
Foods sometime play a role.
Molds may cause symptoms year-round. Ideally the best treatment is avoidance of these substances, but that is impractical in most cases. In the allergic patient, the release of histamine and similar substances results in congestion and excess production of watery nasal mucus. Antihistamines help relieve the sneezing and runny nose of allergy. Many antihistamines are now available without a prescription.