Most humans mount significant IgE responses only as a defense against parasitic infections. However, some individuals mount an IgE response against common environmental antigens. This hereditory predisposition is called atopy. In atopic individuals, non-parasitic antigens stimulate inappropriate IgE production, leading to type I hypersensitivity. A nonparasitic antigen capable of stimulating a type I hypersensitivity reaction in atopic individuals is called an allergen.^[1]

Sensitivities vary from one person to another and it is possible to be allergic to an extraordinary range of substances.

Types of allergies

Dust, pollen and pet dander are all common allergens, but it is possible to be allergic to anything from chlorine to perfume. Food allergies are not as common as food sensitivity, but some foods such as peanuts (really a legume), nuts, seafood and shellfish are the cause of serious allergies in many people.

Officially, the Food and Drug Administration does recognize 8 foods as being common for allergic reactions in a large segment of the sensitive population, which includes, peanuts, tree nuts, eggs, milk, shellfish, fish, wheat and their derivatives, soy and their derivatives, and sulphites (chemical based, often found in flavors and colors in foods) at 10ppm and over. See the FDA website for complete details. It should be noted that other countries, due to differences in genetic profiles of its citizens and different levels of exposure to different foods, the "official" allergen list will change. Canada recognizes all eight of the allergens recognized by the US, and also recognizes Sesame Seeds.^[2]

A few people have been recorded to be allergic to certain chemicals found in almost all water , and even water itself (see Aquagenic pruritus).

Poison ivy is a plant that will cause an allergic reaction in 70-85% of humans. But, given enough repeated contact—like any allergy, most human bodies will learn to fight the allergen.

An allergic reaction can be caused by any form of direct contact with the allergen—eating or drinking a food you are sensitive to (ingestion), breathing in pollen, perfume or pet dander (inhalation), or brushing your body against an allergy-causing plant (direct contact, generally resulting in hives). Other common causes of serious allergy are wasp, fire ant and bee stings, penicillin, and latex. An extremely serious form of an allergic reaction, which can kill in mere minutes, is called anaphylaxis. One form of treatment is the administration of sterile epinephrine (via "Epi-Pen") to the person experiencing anaphylaxis, which suppresses the body's overreaction to the food ingested, and allows for time to be transported to a medical facilty (it does not "cure" the allergic reaction).

Common allergens

In addition to foreign proteins found in foreign serum (from blood transfusions) and vaccines, common allergens include:

• Animal products
• cats
• fur and dander
• cockroach calyx
• dust mite excretion
• Drugs
• penicillin
• sulfonamides
• salicylates (also found naturally in numerous fruits)
• local anaesthetics
• Foods
• celery and celeriac ^[3]
  • *corn or maize
  • eggs (typically albumen, the white)
  • fruit
  • pittster
  • pumpkin
  • legumes
  • beans
  • peas
  • peanuts
  • soybeans
  • milk
  • seafood
  • sesame
  • soy
  • tree nuts
  • pecans
  • almonds
  • wheat
  • Insect stings
  • bee sting venom
  • wasp sting venom
  • mosquito stings
  • Mold spores
  • Other
  • latex
  • metal
  • Plant pollens (hay fever)
  • grass — ryegrass, timothy-grass
  • weeds — ragweed, plantago, nettle, artemisia vulgaris, chenopodium album, sorrel
  • trees — birch, alder, hazel, hornbeam, aesculus, willow, poplar, platanus, tilia, olea

  See also

  • Asthma
  • Bioaerosol
  • Eczema
  • Eggshell skull
  • Hypoallergenic
  • Toxin

  References

  1. ^ Goldsby, Richard A. et al.,Immunology. 5th ed. New York: W.H. Freeman and Company, 2000.
  2. ^ Health Canada: Food Allergies. Retrieved on 2007-06-09.
  3. ^ id="CITEREFBublin MRadauer CWilson IBHKraft D">Bublin M; Radauer C & Wilson IBH et al. (2003), "Cross-reactive N-glycans of Api g 5, a high molecular weight glycoprotein allergen from celery, are required for immunoglobulin E binding and activation of effector cells from allergic patients", FASEB 17: 1697–1699, <[1]
  
  An antigen or immunogen is a molecule that stimulates an immune response. The word originated from the notion that they can stimulate antibody generation. We now know that the immune system does not only consist of antibodies.
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  Atopy
  Classification & external resources
  
  ICD-10 L20
  ICD-9 691
  
  Atopy (Greek ατοπία - placelessness) or atopic syndrome
  ..... Click the link for more information.
  MeSH D006967 Hypersensitivity refers to undesirable (damaging, discomfort-producing and sometimes fatal) reactions produced by the normal immune system. Hypersensitivity reactions require a pre-sensitized (immune) state of the host.
  ..... Click the link for more information.
  Dust is a general name for minute solid particles with diameters less than 500 micrometers. On Earth, dust occurs in the atmosphere from various sources; soil dust lifted up by wind, volcanic eruptions, and pollution are some examples.
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  Pollen is a fine to coarse powder consisting of microgametophytes (pollen grains), which produce the male gametes (sperm cells) of seed plants. The pollen grain with its hard coat protects the sperm cells during the process of their movement between the stamens
  ..... Click the link for more information.

  Not to be confused with Gander.

  
  
  Dander is material shed from the body of various animals, similar to dandruff. It may contain scales of dried skin and hair, or feathers. It is a frequent cause of allergy in humans.
  ..... Click the link for more information.
  1, 3, 5, 7
  (strongly acidic oxide)
  Electronegativity 3.16 (Pauling scale)
  Ionization energies
  (more) 1st: 1251.2 kJmol⁻¹
  2nd: 2298 kJmol⁻¹
  3rd: 3822 kJmol⁻¹
  
  Atomic radius 100 pm
  Atomic radius (calc.
  ..... Click the link for more information.
  Perfume is a mixture of fragrant essential oils and aroma compounds, fixatives, and solvents used to give the human body, objects, and living spaces a pleasant smell.

  Describing a perfume

  
  
  The precise formulas of commercial perfumes are kept secret.
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  Introduction

  Food intolerance or food sensitivity is a negative reaction to a food that may or may not be related to the immune system or to food poisoning.
  ..... Click the link for more information.
  A. hypogaea
  
  Binomial name
  Arachis hypogaea
  L.
  
  

  This article is about the legume. For the comic strip, see Peanuts. For other uses, see Peanut (disambiguation).

  
  ..... Click the link for more information.
  legume is a simple dry fruit which develops from a simple carpel and usually dehisces (opens along a seam) on two sides. A common name for this type of fruit is a "pod", although pod is also applied to a few other fruit types.
  ..... Click the link for more information.
  nut can be either a seed or a fruit.

  Botanical definitions

  A nut in botany is a simple dry fruit with one seed (rarely two) in which the ovary wall becomes very hard (stony or woody) at maturity, and where the seed remains unattached or unfused with the
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  Seafood is any sea animal or seaweed that is served as food or is suitable for eating, particularly seawater animals, such as fish and shellfish (including mollusks and crustaceans).
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  Shellfish is a culinary term for aquatic invertebrates used as food: molluscs, crustaceans, and echinoderms. Both saltwater and freshwater invertebrates are considered shellfish. Shellfish is a misnomer, because these invertebrates are definitely not fish.
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  Water is a common chemical substance that is essential to all known forms of life.^[1] In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor.
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  T. radicans
  
  Binomial name
  Toxicodendron radicans
  (L.) Kuntze
  
  Toxicodendron radicans (syn.
  ..... Click the link for more information.
  worldwide view of the subject.
  Please [ improve this article] or discuss the issue on the talk page.

  
  
  Classification & external resources
  
  ICD-10 T 78.4
  ICD-9 995.
  ..... Click the link for more information.
  Urticaria
  Classification & external resources
  
  ICD-10 L 50.
  ICD-9 708
  
  DiseasesDB 13606
  
  eMedicine emerg/628   Urticaria (or hives
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  wasp is any insect of the order Hymenoptera and suborder Apocrita that is not a bee or ant. The suborder Symphyta includes the sawflies and wood wasps, which differ from members of Apocrita by having a broader connection between the mesosoma and metasoma.
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  Solenopsis
  Westwood, 1840
  
  Species
  
  More than 280 species and subspecies, see text
  Fire ants, sometimes referred to as simply red ants, are stinging ants of which there are over 280 species worldwide.
  ..... Click the link for more information.
  BEE may refer to:

  • Black Economic Empowerment, the policy of post-apartheid affirmative action in South Africa
  • Biblical Education by Extension, a Christian program designed to instruct theology in countries with weak theological infrastructure.

  
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  Penicillin (sometimes abbreviated PCN) is a group of beta-lactam antibiotics used in the treatment of bacterial infections caused by susceptible, usually Gram-positive, organisms.
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  Latex refers generically to a stable dispersion (emulsion) of polymer microparticles in an aqueous medium. Latexes may be natural or synthetic. Latex as found in nature is the milky sap of many plants that coagulates on exposure to air.
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  MeSH D000707 Anaphylaxis is an acute systemic (multi-system) and severe Type I Hypersensitivity allergic reaction in humans and other mammals. The term comes from the Greek words ana (against) and phylaxis (protection).
  ..... Click the link for more information.
  Epinephrine (INN) (IPA: [ˌɛpɪˈnɛfrən]) or adrenaline (European Pharmacopoeia and BAN) (IPA: [əˈdrɛnələn]
  ..... Click the link for more information.
  Blood transfusion is the process of transferring blood or blood-based products from one person into the circulatory system of another. Blood transfusions can be life-saving in some situations, such as massive blood loss due to trauma, or can be used to replace blood lost during
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  A vaccine is an antigenic preparation used to establish immunity to a disease. The term derives from Edward Jenner's use of cowpox ("vacca" means cow in Latin), which, when administered to humans, provided them protection against smallpox, the work which Louis Pasteur and others
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  Cat allergy in humans is an allergic reaction to cat glycoprotein Fel d 1 secreted by the cat's sebaceous glands. Fel d 1 is mostly found in the cat's skin and saliva.
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  fur refers to the body hair of non-human mammals also known as the pelage (like the term plumage in birds). Fur comes from the coats of animals; the animal's coat may consist of short ground hair, long guard hair, and, in some cases, medium awn hair.
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  Not to be confused with Gander.

  
  
  Dander is material shed from the body of various animals, similar to dandruff. It may contain scales of dried skin and hair, or feathers. It is a frequent cause of allergy in humans.
  ..... Click the link for more information.