Subscribe for news updates every 10 minutes. Like/Dislike, Favorite, Comment, Embed on Blog, Facebook Share, and Tweet this video. Get the word out on this video. Get an email once a day tinyurl.com Like on Facebook to get updates tinyurl.com Follow on Twitter to get updates tinyurl.com - Monday June 6 2011 5:15 pm en.wikipedia.org An allergen is any substance that can cause an allergy. Technically, an allergen is a non-parasitic antigen capable of stimulating a type-I hypersensitivity reaction in atopic individuals. Most humans mount significant Immunoglobulin E (IgE) responses only as a defense against parasitic infections. However, some individuals mount an IgE response against common environmental antigens. This hereditary predisposition is called atopy. In atopic individuals, non-parasitic antigens stimulate inappropriate IgE production, leading to type I hypersensitivity. Sensitivities vary widely from one person (or other animal) to another. A very broad range of substances can be allergens to sensitive individuals. Dust mite excretion, pollen and pet dander are all common allergens, but it is possible to be allergic to anything from chlorine to perfume to royal jelly. Food allergies are not as common as food sensitivity, but some foods such as peanuts (a legume), nuts, seafood and shellfish are the cause of serious allergies in many people. Officially, the United States Food and Drug Administration does recognize eight foods as being common for allergic reactions ...