The term allergy has Greek roots, derived from allos meaning “other” and ergon meaning “reaction.” What we know as ‘allergies’ are actually considered to be a Type I Hypersensitivity. A Type I Hypersensitivity is caused by excessive activation of mast cells by the stimulus immunoglobulin E. The body’s response to this excessive activation is what causes symptoms ranging from watery eyes to sudden death.
The first real research done on allergies was in 1906 with Baron Clemens von Pirquet, a Viennese pediatrician. Clemens von Pirquet established basic knowledge about hypersensitivity, coined the term ‘allergy’, and noted common allergens. Since then, doctors have been researching how to prevent and treat allergies, as well as the chemistry behind them.
Most people are familiar with the common reactions to certain allergens. Allergic reactions can be local or systemic and obviously vary from allergen to allergen, and from person to person. Systemic reaction is called anaphylaxis and it is much more severe than local reactions, often resulting in hypertension, coma, or death.
I’ve included this diagram on the right from Wikipedia because I found it very helpful at quickly getting a general understanding of the biology involved. Immunoglobulin E (IgE) is the antibody produced by the body once an allergen is introduced. Once the antibodies encounter the allergen again, they react triggering a bodily response. Immunoglobulin E does have a positive use in the body however: IgE has been observed to help the body resist diseases carried by parasites such as Lyme disease. (Interestingly, IgE has only been found in mammals to date)
Current allergy medications aim to treat the symptoms of common allergic reactions, but currently, chemists are working to stop the problem at the source by neutralizing IgE before it can react. Recent breakthroughs have allowed chemists to determine the structure of IgE (which is unlike other antibodies because of its long and bent shape) hopefully making it easier to develop a treatment.
"Chemistry - Allergy." Chemistry Daily.
http://www.chemistrydaily.com/chemistry/Allergy .
"Immunoglobulin E." Wikipedia.
http://en.wikipedia.org/wiki/IgE.
"What Function Does Immunoglobulin E Serve?" Scientific American
http://www.sciam.com/health/article/id/what-function-does-immuno/topicID/12/catID/3.
Image url:
http://upload.wikimedia.org/wikipedia/commons/thumb/c/ce/Mast_cells.jpg/220px-Mast_cells.jpg
