Rhinitis Medicamentosa Rhinitis medicamentosa (RM) is a condition that caused by overuse of topical nasal steroids. Also known as rebound or chemical rhinitis, the incidence is somewhere between 1-9% of non-allergic rhinitis and it is more common in younger adults and pregnant women. To understand the cause of RM, we must first look at some of the basic science behind the nasal mucosa. The mucosa is innervated by sympathetic fiber that release norepinephrine, which stimulate alpha 1 and alpha 2 receptors. This in turns causes vasoconstriction. The sympathomimetic amines and imidazoline derivatives (phenylephrin and oxymetazoline, respectively) both produce vasoconstriction by endogenous release. | Non-Allergic Rhinitis Ky 2 Rhinitis Medicamentosa Rhinitis medicamentosa RM is a condition that caused by overuse of topical nasal steroids. Also known as rebound or chemical rhinitis the incidence is somewhere between 1-9 of non-allergic rhinitis and it is more common in younger adults and pregnant women. To understand the cause of RM we must first look at some of the basic science behind the nasal mucosa. The mucosa is innervated by sympathetic fiber that release norepinephrine which stimulate alpha 1 and alpha 2 receptors. This in turns causes vasoconstriction. The sympathomimetic amines and imidazoline derivatives phenylephrin and oxymetazoline respectively both produce vasoconstriction by endogenous release of norepinephrine. The problem arises with prolonged use. This leads to reduced production of norepinephrine in the presynapes and decreased sensitivity of the alpha receptors in the postsynapes which in turn requires higher doses for shorter acting time. This cycle of excess dose use and decrease symptomatic relief will lead to worsening of the original symptoms. The risk of RM is greatest after 10 days use of medications. Treatment includes gradual stopping of decongestant with introduction of topical corticosteroid. This will lead to a temporary increase in symptoms and patents should be warned beforehand of this and to not restart the original medication. Patients should be off the medication for 3 months before starting any other surgical or medical treatment for the original nasal disease. NARES NARES non-allergic rhinitis with eosinophilia syndrome is another non-allergic entity that is defined as rhinitis without allergic cause but has 20-25 eosiniophils seen on nasal smears. As with the other NAR disease there is lack of allergy by skin test or IgE antibodies. Prevalence is 13-33 of NAR. NARES etiology is unknown. However it is believed to be associated with the ASA triad as NARES patients tend to develop asthma and nasal polyps later in life and .
