Atopy

Summary

Atopy is the tendency to produce an exaggerated immunoglobulin E (IgE) immune response to otherwise harmless substances in the environment.[2] Allergic diseases are clinical manifestations of such inappropriate, atopic responses.[2]

Atopy
Other namesAtopic syndrome
Eczema—a typical atopic manifestation
Pronunciation
  • /ˈætəp/[1]
SpecialtyDermatology, immunology

Atopy may have a hereditary component, although contact with the allergen or irritant must occur before the hypersensitivity reaction can develop (characteristically after re-exposure).[3] Maternal psychological trauma in utero may also be a strong indicator for development of atopy.[4]

The term atopy was coined by Arthur F. Coca and Robert Cooke in 1923.[5][6] Many physicians and scientists use the term "atopy" for any IgE-mediated reaction (even those that are appropriate and proportional to the antigen), but many pediatricians reserve the word "atopy" for a genetically mediated predisposition to an excessive IgE reaction.[7] The term is from Greek ἀτοπία meaning "the state of being out of place", "absurdity".[8]

Signs and symptoms edit

Atopic sensitization is considered IgE positivity or prick test positivity to any common food- or air-borne allergen.[9] Atopic conditions are considered: atopic dermatitis, allergic rhinitis (hay fever), allergic asthma, atopic keratoconjunctivitis. The likelihood of having asthma, rhinitis and atopic dermatitis together is 10 times higher than could be expected by chance.[10] Atopy is more common among individuals with a number of different conditions, such as eosinophilic esophagitis and non-celiac gluten sensitivity.[11][12]

Allergic reactions can range from sneezing and rhinorrhoea to anaphylaxis and even death.[13]

Pathophysiology edit

In an allergic reaction, initial exposure to an otherwise harmless exogenous substance (known as an allergen) triggers the production of specific IgE antibodies by activated B cells.[13] These IgE antibodies bind to the surface of mast cells via high-affinity IgE receptors, a step that is not itself associated with a clinical response.[13] However, upon re-exposure, the allergen binds to membrane-bound IgE which activates the mast cells, releasing a variety of mediators.[13] This type I hypersensitivity reaction is the basis of the symptoms of allergic reactions, which range from sneezing and rhinorrhoea to anaphylaxis.[13] Allergens can be a number of different substances, for example pollen, dander, dust mites, and foods.

Causes edit

Atopic reactions are caused by localized hypersensitivity reactions to an allergen. Atopy appears to show a strong hereditary component. One study concludes that the risk of developing atopic dermatitis (3%) or atopy in general (7%) "increases by a factor of two with each first-degree family member already suffering from atopy".[14] As well, maternal stress and perinatal programming is increasingly understood as a root cause of atopy, finding that "...trauma may be a particularly robust potentiator of the cascade of biological events that increase vulnerability to atopy and may help explain the increased risk found in low-income urban populations."[4]

Environmental factors are also thought to play a role in the development of atopy, and the 'hygiene hypothesis' is one of the models that may explain the steep rise in the incidence of atopic diseases, though this hypothesis is incomplete and in some cases, contradictory to findings.[4] This hypothesis proposes that excess 'cleanliness' in an infant's or child's environment can lead to a decline in the number of infectious stimuli that are necessary for the proper development of the immune system. The decrease in exposure to infectious stimuli may result in an imbalance between the infectious-response ("protective") elements and the allergic-response ("false alarm") elements within the immune system.[15]

Some studies also suggest that the maternal diet during pregnancy may be a causal factor in atopic diseases (including asthma) in offspring, suggesting that consumption of antioxidants, certain lipids, and/or a Mediterranean diet may help to prevent atopic diseases.

A Swedish research study titled "Atopy In Children Of Families With An Anthroposophic Lifestyle" comparing the rate of bronchial asthma, allergies, dermatitis, and other atopic diseases among Steiner school pupils and pupils in public schools originally appeared in the May 1, 1999, edition of the British medical journal The Lancet. The findings indicated that Steiner school pupils were "at a significantly lower risk of atopy" than children attending public schools. The researchers investigated a variety of factors in the lives of the Steiner school pupils that might have contributed to this lower rate of atopy, which included breastfeeding, reduced immunization, avoidance of antibiotics and medications that reduce fevers, consumption of bio-dynamic and organic foods, and other physical aspects of the children's lives. [16]

The multicenter PARSIFAL study in 2006, involving 6,630 children age 5 to 13 in 5 European countries, suggested that reduced use of antibiotics and antipyretics is associated with a reduced risk of allergic disease in children.[17]

Genetics edit

There is a strong genetic predisposition toward atopic allergies, especially on the maternal side. Because of the strong familial evidence, investigators have tried to map susceptibility genes for atopy.[18][19] Genes for atopy (C11orf30, STAT6, SLC25A46, HLA-DQB1, IL1RL1/IL18R1, TLR1/TLR6/TLR10, LPP, MYC/PVT1, IL2/ADAD1, HLA-B/MICA)[20] tend to be involved in allergic responses or other components of the immune system. The gene C11orf30 seems to be the most relevant for atopy as it may increase susceptibility to poly-sensitization.[21]

Staphylococcus aureus edit

Bleach baths provide temporary control of eczema.[22] Ciprofloxacin is an allergen that may cause contact dermatitis, symptoms of which are indistinguishable from eczema.[23] Filaggrin mutations are associated with atopic eczema and may contribute to the excessive dryness of the skin and the loss of the barrier function of normal skin.[24] It may be possible that the filaggrin mutations and the loss of the normal skin barrier expose crevices that make it possible for Staphylococcus aureus to colonize the skin.[25] Atopic eczema is often associated with genetic defects in genes that control allergic responses. Thus, some investigators have proposed that atopic eczema is an allergic response to increased Staphylococcus aureus colonization of the skin.[26] A hallmark indicator of atopic eczema is a positive wheal and flare reaction to a skin test of S. aureus antigens. In addition, several studies have documented that an IgE-mediated response to S. aureus is present in people with atopic eczema.[27][28]

Changes in prevalence over time edit

In adults, the prevalence of IgE sensitization to allergens from house dust mite and cat, but not grass, seems to decrease over time as people age.[29] However, the biological reasons for these changes are not fully understood.

Treatments edit

Treatments for atopic disorders depend on the organ(s) involved. They can vary from local treatment options, often topical corticosteroids, to systemic treatment options with oral corticosteroids, biological treatments (e.g. omalizumab, mepolizumab) or allergen immunotherapy.[30][31][32]

See also edit

References edit

  1. ^ Merriam-Webster Dictionary: Atopy
  2. ^ a b Ralston, Stuart H., Herausgeber. Penman, Ian D., Herausgeber. Strachan, Mark W. J., Herausgeber. Hobson, Richard P., Herausgeber. Britton, Robert, Illustrator. Davidson, Leybourne S. 1894-1981 Begründer des Werks. (2018-04-23). Davidson's principles and practice of medicine. Elsevier. ISBN 978-0-7020-7028-0. OCLC 1040673074.{{cite book}}: CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link)
  3. ^ "Mosby's Medical Dictionary:atopy". Archived from the original on 2011-07-10.
  4. ^ a b c Wright, Rosalind J; Enlow, Michelle Bosquet (2008-09-01). "Maternal stress and perinatal programming in the expression of atopy". Expert Review of Clinical Immunology. 4 (5): 535–538. doi:10.1586/1744666X.4.5.535. ISSN 1744-666X. PMC 2762209. PMID 19838310.
  5. ^ Coca AF, Cooke RA. (1923) On the classification of the phenomenon of hypersensitiveness J Immunol
  6. ^ Johannes Ring; Bernhard Przybilla; Thomas Ruzicka (2006). Handbook of atopic eczema. Birkhäuser. pp. 3–. ISBN 978-3-540-23133-2. Retrieved 4 May 2010.
  7. ^ Ruby Pawankar; Stephen T. Holgate; Lanny J. Rosenwasser (7 April 2009). Allergy Frontiers: Classification and Pathomechanisms. Springer. pp. 33–. ISBN 978-4-431-88314-2. Retrieved 4 May 2010.
  8. ^ "atopy". Online Etymology Dictionary. Douglas Harper. 2019. Retrieved 26 Sep 2019.
  9. ^ Simpson, Angela; Tan, Vincent Y. F.; Winn, John; Svensén, Markus; Bishop, Christopher M.; Heckerman, David E.; Buchan, Iain; Custovic, Adnan (June 2010). "Beyond Atopy" (PDF). American Journal of Respiratory and Critical Care Medicine. 181 (11): 1200–1206. doi:10.1164/rccm.200907-1101oc. ISSN 1073-449X. PMID 20167852.
  10. ^ Sun, Hai-Lun; Yeh, Chih-Jung; Ku, Min-Sho; Lue, Ko-Huang (2012-01-01). "Coexistence of allergic diseases: Patterns and frequencies". Allergy and Asthma Proceedings. 33 (1): e1-4. doi:10.2500/aap.2012.33.3506. ISSN 1088-5412. PMID 22370527.
  11. ^ Mansueto P, Seidita A, D'Alcamo A, Carroccio A (2014). "Non-celiac gluten sensitivity: literature review" (PDF). J Am Coll Nutr (Review). 33 (1): 39–54. doi:10.1080/07315724.2014.869996. hdl:10447/90208. PMID 24533607. S2CID 22521576.
  12. ^ González-Cervera J, Arias Á, Redondo-González O, Cano-Mollinedo MM, Terreehorst I, Lucendo AJ (2017). "Association between atopic manifestations and eosinophilic esophagitis: A systematic review and meta-analysis". Ann Allergy Asthma Immunol (Systematic Review and Meta-analysis). 118 (5): 582–590.e2. doi:10.1016/j.anai.2017.02.006. PMID 28366582.
  13. ^ a b c d e "Davidson's Principles and Practice of Medicine, IE Edition, 20th Ed: Medicine—Clinical Medicine". Journal of Endocrinology, Metabolism and Diabetes of South Africa. 13 (2): 75. July 2008. doi:10.1080/22201009.2008.10872174. ISSN 1608-9677. S2CID 220276722.
  14. ^ Küster, W.; Petersen, M.; Christophers, E.; Goos, M.; Sterry, W. (December 12, 2004). "A family study of atopic dermatitis". Archives of Dermatological Research. 282 (2 / January, 1990): 98–102. doi:10.1007/BF00493466. PMID 2353830. S2CID 9396200.
  15. ^ Grammatikos AP (2008). "The genetic and environmental basis of atopic diseases". Ann. Med. 40 (7): 482–95. doi:10.1080/07853890802082096. PMID 18608118. S2CID 188280.
  16. ^ Alm, Johan S; Swartz, Jackie; Lilja, Gunnar; Scheynius, Annika; Pershagen, Göran (May 1999). "Atopy in children of families with an anthroposophic lifestyle". The Lancet. 353 (9163): 1485–1488. CiteSeerX 10.1.1.586.4628. doi:10.1016/S0140-6736(98)09344-1. PMID 10232315. S2CID 27540120.
  17. ^ Flöistrup H, Swartz J, Bergström A; et al. (January 2006). "Allergic disease and sensitization in Steiner school children" (PDF). J. Allergy Clin. Immunol. 117 (1): 59–66. doi:10.1016/j.jaci.2005.09.039. PMID 16387585. Archived from the original (PDF) on 2007-09-27. Retrieved 2007-07-18.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  18. ^ Blumenthal MN (2005). "The Role of Genetics in the Development of Asthma and Atopy". Curr Opin Allergy Clin Immunol. 5 (141–5): 141–5. doi:10.1097/01.all.0000162306.12728.c2. PMID 15764904. S2CID 30698973.
  19. ^ Hoffjan S, Nicolae D, Ober C (2003). "Association Studies for Asthma and Atopic Diseases: A Comprehensive Review of the Literature". Respir Res. 4 (14): 14748924. doi:10.1186/1465-9921-4-14. PMC 314398. PMID 14748924.
  20. ^ Bønnelykke, Klaus; Matheson, Melanie C; Pers, Tune H; Granell, Raquel; Strachan, David P; Alves, Alexessander Couto; Linneberg, Allan; Curtin, John A; Warrington, Nicole M; Standl, Marie; Kerkhof, Marjan; Jonsdottir, Ingileif; Bukvic, Blazenka K; Kaakinen, Marika; Sleimann, Patrick; Thorleifsson, Gudmar; Thorsteinsdottir, Unnur; Schramm, Katharina; Baltic, Svetlana; Kreiner-Møller, Eskil; Simpson, Angela; Pourcain, Beate St; Coin, Lachlan; Hui, Jennie; Walters, Eugene H; Tiesler, Carla M T; Duffy, David L; Jones, Graham; Ring, Susan M; McArdle, Wendy L; Price, Loren; Robertson, Colin F; Pekkanen, Juha; Tang, Clara S; Thiering, Elisabeth; Montgomery, Grant W; Hartikainen, Anna-Liisa; Dharmage, Shyamali C; Husemoen, Lise L; Herder, Christian; Kemp, John P; Elliot, Paul; James, Alan; Waldenberger, Melanie; Abramson, Michael J; Fairfax, Benjamin P; Knight, Julian C; Gupta, Ramneek; Thompson, Philip J; Holt, Patrick; Sly, Peter; Hirschhorn, Joel N; Blekic, Mario; Weidinger, Stephan; Hakonarsson, Hakon; Stefansson, Kari; Heinrich, Joachim; Postma, Dirkje S; Custovic, Adnan; Pennell, Craig E; Jarvelin, Marjo-Riitta; Koppelman, Gerard H; Timpson, Nicholas; Ferreira, Manuel A; Bisgaard, Hans; Henderson, A John (30 June 2013). "Meta-analysis of genome-wide association studies identifies ten loci influencing allergic sensitization". Nature Genetics. 45 (8): 902–906. doi:10.1038/ng.2694. PMC 4922420. PMID 23817571.
  21. ^ Amaral, André F. S.; Minelli, Cosetta; Guerra, Stefano; Wjst, Matthias; Probst-Hensch, Nicole; Pin, Isabelle; Svanes, Cecilie; Janson, Christer; Heinrich, Joachim; Jarvis, Deborah L. (December 2014). "The locus increases susceptibility to poly-sensitisation" (PDF). Allergy. 70 (3): 328–333. doi:10.1111/all.12557. hdl:10044/1/21574. PMID 25546184. S2CID 25960081.
  22. ^ Nguyen, T.; Zuniga, R. (2013). "Skin conditions: New drugs for managing skin disorders". FP Essentials. 407: 11–16. PMID 23600334.
  23. ^ Lee, S. W.; Cheong, S. H.; Byun, J. Y.; Choi, Y. W.; Choi, H. Y. (2013). "Occupational hand eczema among nursing staffs in Korea: Self-reported hand eczema and contact sensitization of hospital nursing staffs". The Journal of Dermatology. 40 (3): 182–187. doi:10.1111/1346-8138.12036. PMID 23294332. S2CID 33771711.
  24. ^ O'Regan GM, Sandilands A, McLean WH, Irvine AD (2008). "Filaggrin in Atopic Dermatitis". J Allergy Clin Immunol. 122 (4): 689–93. doi:10.1016/j.jaci.2008.08.002. PMID 18774165.
  25. ^ Breuer K, Kapp A, Werfel T (2001). "Bacterial Infections and Atopic Dermatitis". Allergy. 56 (11): 1034–41. doi:10.1034/j.1398-9995.2001.00146.x. PMID 11703215. S2CID 28897487.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  26. ^ Abramson JS, Dahl MV, Walsh G, Blumenthal MN, Douglas SD, Quie PG (1982). "Antistaphylococcal IgE in Patients with Atopic Dermatitis". J Am Acad Dermatol. 7 (1): 105–110. doi:10.1016/s0190-9622(82)80017-0. PMID 7107990.
  27. ^ Parish WE, Welbourn E, Champion RH (1976). "Hypersensitivity to Bacteria in Eczema. Ii. Titre and Immunoglobulin Class of Antibodies to Staphylococci and Micrococci". Br J Dermatol. 95 (3): 285–93. doi:10.1111/j.1365-2133.1976.tb07016.x. PMID 974019. S2CID 5842899.
  28. ^ Motala C, Potter PC, Weinberg EG, Malherbe D, Hughes J (1986). "Anti-Staphylococcus aureus-Specific IgE in Atopic Dermatitis". J Allergy Clin Immunol. 78 (4 Pt 1): 583–9. doi:10.1016/0091-6749(86)90075-8. PMID 3771950.
  29. ^ Amaral, André F.S.; Newson, Roger B.; Abramson, Michael J.; Antó, Josep M.; Bono, Roberto; Corsico, Angelo G.; de Marco, Roberto; Demoly, Pascal; Forsberg, Bertil; Gislason, Thorarinn; Heinrich, Joachim; Huerta, Ismael; Janson, Christer; Jõgi, Rain; Kim, Jeong-Lim; Maldonado, José; Martinez-Moratalla Rovira, Jesús; Neukirch, Catherine; Nowak, Dennis; Pin, Isabelle; Probst-Hensch, Nicole; Raherison-Semjen, Chantal; Svanes, Cecilie; Urrutia Landa, Isabel; van Ree, Ronald; Versteeg, Serge A.; Weyler, Joost; Zock, Jan-Paul; Burney, Peter G.J.; Jarvis, Deborah L. (November 2015). "Changes in IgE sensitization and total IgE levels over 20 years of follow-up". Journal of Allergy and Clinical Immunology. 137 (6): 1788–1795.e9. doi:10.1016/j.jaci.2015.09.037. PMC 4889785. PMID 26586040.
  30. ^ Wollenberg, A.; Barbarot, S.; Bieber, T.; Christen-Zaech, S.; Deleuran, M.; Fink-Wagner, A.; Gieler, U.; Girolomoni, G.; Lau, S.; Muraro, A.; Czarnecka-Operacz, M. (May 2018). "Consensus-based European guidelines for treatment of atopic eczema (atopic dermatitis) in adults and children: part I". Journal of the European Academy of Dermatology and Venereology. 32 (5): 657–682. doi:10.1111/jdv.14891. PMID 29676534.
  31. ^ Reddel, Helen K.; Bateman, Eric D.; Becker, Allan; Boulet, Louis-Philippe; Cruz, Alvaro A.; Drazen, Jeffrey M.; Haahtela, Tari; Hurd, Suzanne S.; Inoue, Hiromasa; de Jongste, Johan C.; Lemanske, Robert F. (September 2015). "A summary of the new GINA strategy: a roadmap to asthma control". European Respiratory Journal. 46 (3): 622–639. doi:10.1183/13993003.00853-2015. ISSN 0903-1936. PMC 4554554. PMID 26206872.
  32. ^ Klimek, Ludger; Bachert, Claus; Pfaar, Oliver; Becker, Sven; Bieber, Thomas; Brehler, Randolf; Buhl, Roland; Casper, Ingrid; Chaker, Adam; Czech, Wolfgang; Fischer, Jörg (2020-02-12). "Correction to "ARIA guideline 2019: treatment of allergic rhinitis in the German health system"". Allergo Journal International. 29 (2): 63–65. doi:10.1007/s40629-019-00115-4. ISSN 2197-0378. S2CID 211089322.

External links edit

  • Case Studies in Environmental Medicine (CSEM): Environmental Triggers of Asthma – Agency for Toxic Substances and Disease Registry, U.S. Department of Health and Human Services.