Rhinitis peppers). The quality of evidence is low, however. Allergic rhinitis or hay fever may follow when an allergen such as pollen, dust, or Balsam of Peru is inhaled by an individual with a sensitized immune system, triggering antibody production. These antibodies mostly bind to mast cells, which contain histamine. When the mast cells are stimulated by an allergen, histamine (and other chemicals) are released. This causes itching, swelling, and mucus production. Symptoms vary in severity between individuals. Very sensitive individuals can experience hives or other rashes. Particulate matter in polluted air and chemicals such as chlorine and detergents, which can
Rhinitis medicamentosa Rhinitis medicamentosa Rhinitis medicamentosa (or RM) is a condition of rebound nasal congestion brought on by extended use of topical decongestants (e.g., oxymetazoline, phenylephrine, xylometazoline, and naphazoline nasal sprays) and certain oral medications (e.g., sympathomimetic amines and various 2-imidazolines) that constrict blood vessels in the lining of the nose. The characteristic presentation of RM involves nasal congestion without rhinorrhea, postnasal drip, or sneezing following several days of decongestant use. This condition typically occurs after 5–7 days of use of topical decongestants. Patients often try increasing both the dose and the frequency of nasal sprays upon the onset of RM, worsening