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Immunology => Asthma => Hay fever
Hay fever
Hay Fever, form of seasonal rhinitis caused by allergy to pollens. Its symptoms are intense seizures of sneezing, inflammation of nose and eye membranes, and wheezing. Hay fever occurs annually at the same season. It is a reaction to inhalation of airborne pollens to which an individual is sensitive. Individuals with a family history of hay fever may inherit a tendency to react, not to specific allergens, but to those to which they are exposed. Up to 10 per cent of the population of Europe and the United States are affected.
A doctor may determine the sensitizing agent or agents by scratching the skin of the patient and applying various pollens. The pollens to which the patient is allergic will produce a wheal-and-flare reaction. Because hay fever involves an antigen-antibody reaction in which histamine in the body is released and irritates blood vessels and glands, some antihistaminic agents may furnish relief. Long-term treatment involves a series of injections of pollen extracts before the pollen season begins; repeated annually, these relieve 75 per cent of cases, by gradual desensitization.
"Hay Fever," Microsoft® Encarta® Encyclopedia 2000. © 1993-1999 Microsoft Corporation. All rights reserved.
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