Many people are affected by seasonal allergies. In the springtime, various outdoor allergens such as flower buds and pollen cause an immune reaction in susceptible people. Reactions such as sneezing, congestion, and runny nose are characteristic of seasonal allergies. Sensitization is the process that occurs in individuals affected by hay fever, in which the immune system identifies the allergen as a foreign substance, and therefore produces an antibody, known as immunoglobulin E (IgE), against that allergen. These antibodies cause the release of substances such as histamine, which causes the characteristic signs and symptoms of hay fever.
Pseudoepedrine (Sudafed) is an oral decongestant available overthe-counter (OTC). Phenylephrine (Neo-Synephrine) and oxymetazoline (Afrin) are available OTC nasal decongestants. Decongestant nasal sprays should not be used for longer than 2 or 3 days at a time. Antihistamines work to alleviate sneezing, runny nose, and itching. Diphenhydramine (Benadryl) and chlorpheniramine (Chlor-Trimeton) are available OTC antihistamines. Loratadine (Claritin, Alavert) is a newer type of antihistamine that is less likely to cause sleepiness. Cromolyn sodium (NasalCrom) is an available OTC nasal spray, which works by preventing the release of histamine.