Until recently, corticosteroids, although very effective in controlling allergic disorders, were not widely used for pollen allergy because their prolonged use can result in serious sided effects. Corticosteroids relieve the symptoms of pollen allergy by reducing nasal inflammation and inhibiting mucus production. Locally active steroids that penetrate the nasal membrane are now available as nasal sprays in measured-dose spray bottles. When used this way, the drug affects only the nasal passages rather than the entire body. The side effects, which are minimal when the spray is used in recommended doses, can include nasal burning and dryness and a sore throat.

Cromolyn sodium. Another effective agent that is available by prescription as a nasal solution is cromolyn sodium. Unlike antihistamines or steroids, cromolyn sodium is believed to control allergic symptoms by preventing the mast cells from releasing histamine. In clinical trials, cromolyn sodium has been proven safe and effective and, in contrast to some other allergy medications, appears to cause no drowsiness. Unlike antihistamines and decongestants, corticosteroid nasal sprays and cromolyn sodium nasal solutions must be used for several days to weeks before there is any noticeable reduction in symptoms.