Not all peanut-sensitized children develop allergic reactions on exposure.The study authors ascertained peanut sensitization by skin tests and IgE measurement at age 8 years. Among sensitized children, the diagnosis of peanut allergy versus tolerance was determined by oral food challenges.
They used open challenge among children consuming peanuts (n = 45); others underwent double-blind placebo-controlled challenge (n = 34).
Of 933 children, 11.8% were peanut-sensitized. 19 children were not challenged (17 did not consent).
12 children with a convincing history of reactions on exposure, IgE greater than 15 kUa/L and/or skin test greater than 8mm were considered allergic without challenge.
Of the remaining 79 children who underwent challenge, 7 had more than 2 objective signs and were designated as having peanut allergy.
The prevalence of clinical peanut allergy among sensitized subjects was 22.4%.
Component-resolved diagnostics using microarray detected differences in component recognition between children with peanut allergy and peanut-tolerant children. The peanut component Ara h 2 was the most important predictor of clinical allergy.
The study authors concluded that the majority of children considered peanut-sensitized on the basis of standard tests do not have peanut allergy. Component-resolved diagnostics may facilitate the diagnosis of peanut allergy.
Eight top allergens account for 90 % of all food allergies. They can be remembered by the mnemonic TEMPS WFS:
Tree nuts (almonds, cashews, walnuts)
Egg white (not egg yolk)
Milk
Peanuts
Shellfish (crab, lobster, shrimp)
Wheat
Fish (bass, cod, flounder)
Soy
Molecular Allergy Component Testing, a video by the manufacturer of ImmunoCAP testing system.
This video by the manufacturer of sIgE assays Phadia tries to explain the concept of Molecular Allergology in two minutes:
References:
Allergy or tolerance in children sensitized to peanut: Prevalence and differentiation using component-resolved diagnostics. Nicolaou N, Poorafshar M, Murray C, Simpson A, Winell H, Kerry G, Härlin A, Woodcock A, Ahlstedt S, Custovic A. J Allergy Clin Immunol. 2010 Jan;125(1):191-197.e13.
http://www.ncbi.nlm.nih.gov/pubmed/20109746?dopt=Abstract
Parents upset children use extensive cleaning measures to ensure they don’t sicken a classmate with peanut allergy http://goo.gl/mK2Qb
Peanut Allergy: An Evolving Clinical Challenge (review), 2011.
Component-Resolved Diagnosis in Pediatric Allergy http://bit.ly/SG6FNJ
Peanut Allergy: An Evolving Clinical Challenge (review), 2011.
Component-Resolved Diagnosis in Pediatric Allergy http://bit.ly/SG6FNJ
Blog articles from AllergyNotes
Image source: Roasted peanuts as snack food, Wikipedia, public domain.
Below is a marketing video from ImmunoCAP Peanut Component test. From the test manufacturer's YouTube channel: "The mother of a patient shared the story of her son who was diagnosed with multiple food allergies as an infant. After a peanut allergy diagnosis, the family's world was turned upside down. Recently, when starting Kindergarten, his doctor recommended the ImmunoCAP Peanut Component tests and, like 75% of all peanut sensitized individuals, the test results indicated he was not clinically allergic. He can now eat peanuts without fear."
If we have a child who has peanut allergy, does that mean he/she is allergic to beans, nuts (like almond and walnuts) or anything in the legume botanical family too? Please give the information. Thank you.
ReplyDeleteCross-reactivity between peanut and legumes is 5%. See an allergist for proper evaluation and testing.
ReplyDelete