Editing Allergy (section)

==History==
Some symptoms attributable to allergic diseases are mentioned in ancient sources.<ref name="aai">{{Cite journal | url =https://aai.org.tr/index.php/aai/article/download/406/321 |title=Were Allergic Diseases Prevalent in Antiquity?|author1=Kürşat Epöztürk |author2=Şefik Görkey|journal=Asthma Allergy Immunol| doi=10.21911/aai.406|date=2018| access-date =22 September 2018|doi-access=free|hdl=11424/219799|hdl-access=free}}</ref> Particularly, three members of the Roman [[Julio-Claudian dynasty]] ([[Augustus]], [[Claudius]] and [[Britannicus]]) are suspected to have a family history of atopy.<ref name="aai"/><ref>{{cite journal |title=1st description of an "atopic family anamnesis" in the Julio-Claudian imperial house: Augustus, Claudius, Britannicus|author=Ring J.|pmid=3899999| date=August 1985| volume=36|issue = 8| journal=Hautarzt| pages=470–71}}</ref> The concept of "allergy" was originally introduced in 1906 by the [[Vienna, Austria|Viennese]] [[pediatrician]] [[Clemens von Pirquet]], after he noticed that patients who had received injections of horse serum or smallpox vaccine usually had quicker, more severe reactions to second injections.<ref>{{WhoNamedIt|Doctor|2382|Clemens Peter Pirquet von Cesenatico}}</ref> Pirquet called this phenomenon "allergy" from the [[Ancient Greek language|Ancient Greek]] words [[wikt:ἄλλος|ἄλλος]] ''allos'' meaning "other" and [[wikt:ἔργον|ἔργον]] ''ergon'' meaning "work".<ref name="Allergie"/>

All forms of hypersensitivity used to be classified as allergies, and all were thought to be caused by an improper activation of the immune system. Later, it became clear that several different disease mechanisms were implicated, with a common link to a disordered activation of the immune system. In 1963, a new classification scheme was designed by [[Philip George Houthem Gell|Philip Gell]] and [[Robin Coombs]] that described four types of [[hypersensitivities|hypersensitivity reactions]], known as Type I to Type IV hypersensitivity.<ref name="GellCoombs"/>

With this new classification, the word ''allergy'', sometimes clarified as a ''true allergy'', was restricted to type I hypersensitivities (also called immediate hypersensitivity), which are characterized as rapidly developing reactions involving IgE antibodies.<ref>{{Cite book|url=https://books.google.com/books?id=sXagBwAAQBAJ&pg=PA361|title=The Complement System: Novel Roles in Health and Disease| vauthors = Szebeni J |date=8 May 2007|publisher=Springer Science & Business Media|isbn=978-1-4020-8056-2|pages=361|language=en}}</ref>

A major breakthrough in understanding the mechanisms of allergy was the discovery of the antibody class labeled [[immunoglobulin E]] (IgE). IgE was simultaneously discovered in 1966–67 by two independent groups:<ref>{{cite journal | vauthors = Stanworth DR | title = The discovery of IgE | journal = Allergy | volume = 48 | issue = 2 | pages = 67–71 | date = February 1993 | pmid = 8457034 | doi = 10.1111/j.1398-9995.1993.tb00687.x | s2cid = 36262710 | doi-access = free }}</ref> [[Kimishige Ishizaka|Ishizaka]]'s team at the Children's Asthma Research Institute and Hospital in Denver, USA,<ref name="Ishizaka K"/> and by Gunnar Johansson and Hans Bennich in Uppsala, Sweden.<ref>Johansson SG, Bennich H. Immunological studies of an atypical (myeloma) immunoglobulin" ''Immunology'' 1967; 13:381–94.</ref> Their joint paper was published in April 1969.<ref name="Joint paper 1969">{{cite journal | vauthors = Ishizaka T, Ishizaka K, Johansson SG, Bennich H | title = Histamine release from human leukocytes by anti-gamma E antibodies | journal = Journal of Immunology | volume = 102 | issue = 4 | pages = 884–892 | date = April 1969 | pmid = 4181251 | doi = 10.4049/jimmunol.102.4.884 | s2cid = 255338552 | doi-access = free }}</ref>

===Diagnosis===
Radiometric assays include the [[radioallergosorbent test]] (RAST test) method, which uses IgE-binding (anti-IgE) antibodies labeled with [[radioactive isotope]]s for quantifying the levels of IgE antibody in the blood.<ref name="pmid7630219">{{cite journal | vauthors = Ten RM, Klein JS, Frigas E | title = Allergy skin testing | journal = Mayo Clinic Proceedings | volume = 70 | issue = 8 | pages = 783–84 | date = August 1995 | pmid = 7630219 | doi = 10.4065/70.8.783 | url = http://www.mayoclinicproceedings.org/article/S0025-6196(11)64353-X/abstract }}</ref>

The RAST methodology was invented and marketed in 1974 by Pharmacia Diagnostics AB, Uppsala, Sweden, and the acronym RAST is actually a brand name. In 1989, Pharmacia Diagnostics AB replaced it with a superior test named the ImmunoCAP Specific IgE blood test, which uses the newer fluorescence-labeled technology.<ref name="n663">{{cite book | last=Mccarty | first=C. | title=Immunology: Essential and Fundamental | publisher=EDTECH | year=2018 | isbn=978-1-83947-284-8 | url=https://books.google.com/books?id=UePEDwAAQBAJ&pg=PA228 | access-date=2024-06-29 | page=228}}</ref>

[[American College of Allergy, Asthma and Immunology|American College of Allergy Asthma and Immunology]] (ACAAI) and the [[American Academy of Allergy, Asthma, and Immunology|American Academy of Allergy Asthma and Immunology]] (AAAAI) issued the Joint Task Force Report "Pearls and pitfalls of allergy diagnostic testing" in 2008, and is firm in its statement that the term RAST is now obsolete:

{{blockquote|The term RAST became a colloquialism for all varieties of (in vitro allergy) tests.  This is unfortunate because it is well recognized that there are well-performing tests and some that do not perform so well, yet they are all called RASTs, making it difficult to distinguish which is which. For these reasons, it is now recommended that use of RAST as a generic descriptor of these tests be abandoned.<ref name="Cox2008" />}}

The updated version, the ImmunoCAP Specific IgE blood test, is the only specific IgE assay to receive [[Food and Drug Administration]] approval to quantitatively report to its detection limit of 0.1kU/L.<ref name="n663"/>