Allergic rhinitis, chronic inflammation of the lining membrane of the nose, is triggered by allergens such as trees, grasses, weeds, dust mites, and animal dander. The interaction between allergens, IgE and our mast cells and basophiles triggers the release of chemical mediators such as histamine, prostaglandins, and leukotrienes to name a few.
The first step in treating allergic rhinitis is to avoid the offending allergen. Decreasing the body’s production of specific IgE with the help of immunotherapy (allergy shots) is another alternative. Most patients, however, can feel relief with medication in addition to allergen avoidance. The pharmacological approach focuses on decreasing inflammation by stabilizing mast cells and basophiles while decreasing the release of chemical mediators, and blocking the effects of histamine, leukotrienes, and prostaglandins.
Antihistamines, which we discussed in a previous column, can effectively treat most allergic symptoms, except nasal congestion or inflammation. Currently, the most effective medication available to control sneezing, itching, a runny nose and nasal congestion are corticosteroid nasal sprays such as Flonase, Nasacort AQ, Nasonex, and Rhinocort AQ. Corticosteroid nasal sprays can block leukotriens and prostaglandins and reduce inflammation which is the cause of allergic symptoms. These sprays must be used regularlyin order for them to work and it may take one to three weeks to achieve maximum benefit.
While side effects of corticosteroid nasal sprays are generally mild and limited to the nose, common ones, if the used incorrectly, include burning, stinging, and irritation of the lining of the nose or nasal septum (the wall that divides the nose into right /left sides) rarely. Patients are advised not to point the nozzle of the spray toward the nasal septum as this can injure the septum. Rather, the nozzle should be pointed slanted back, following the direction of airflow into the nose.
Cromolyn sodium, which is not an antihistamine, decongestant or steroid, is widely prescribed because of its ability to prevent the release of these chemicals from mast cells into the nasal tissue. For the best results, Cromolyn sodium should be started two weeks before allergy season. Although Cromolyn is not as effective as corticosteroid nasal sprays, doctors may often prescribe it for children and pregnant woman because of its excellent safety profile and minor side effects.
The antihistamine nasal spray (Astelin), which usually takes effect within three hours and in contrast to most oral antihistamines, is also effective in helping reduce nasal congestion.
Finally, Singulair (montelukast sodium) can block leukotriene effects and relieve allergic symptoms, but not as effectively as corticosteroid nasal sprays. However, because Singulair is in pill form, it can also be used to treat mild asthma and is therefore a good choice for patients with mild allergic rhinitis and asthma.