Rhinitis, inflammation of the mucous lining of the nose, is a nonspecific term that covers infections, allergies, and other disorders whose common feature is the location of their symptoms. These symptoms include infected or irritated mucous membranes, producing a discharge, congestion, and swelling of the tissues of the nasal passages. The most widespread form of infectious rhinitis is the common cold.

The common cold is the most frequent viral infection in the general population, causing more absenteeism from school or work than any other illness. Colds are self-limited, lasting about 3-10 days, although they are sometimes followed by a bacterial infection. Children are more susceptible than adults; teenage boys than teenage girls; and adult women than adult men. In the United States, colds are most frequent during the late fall and winter.

Colds can be caused by as many as 200 different viruses which are transmitted by sneezing and...