Majority of children considered peanut-sensitized by standard tests may not actually have peanut allergy
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.
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
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."
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."