Establishing the diagnosis of peanut allergy in children never exposed to peanut or with an uncertain history: a cross-Canada study (original) (raw)

Rising prevalence of allergy to peanut in children: Data from 2 sequential cohorts

Journal of Allergy and Clinical Immunology, 2002

Background: Allergy to peanut is common. However, it is not known whether the prevalence of sensitization and clinical allergy to peanut is increasing. Objective: We sought to determine any change in the prevalence of peanut sensitization and reactivity in early childhood in 2 sequential cohorts in the same geographic area 6 years apart. Methods: Of 2878 children born between September 1, 1994, and August 31, 1996, living on the Isle of Wight, 1273 completed questionnaires, and 1246 had skin prick tests at the age of 3 to 4 years. Those with positive skin prick test responses to peanut were subjected to oral peanut challenges, unless there was a history of immediate systemic reaction. These data were compared with information on sensitization and clinical allergy to peanut available from a previous cohort born in 1989 in the same geographic area. Results: There was a 2-fold increase in reported peanut allergy (0.5% [6/1218] to 1.0% [13/1273]), but the difference was nonsignificant (P = .2). Peanut sensitization increased 3-fold, with 41 (3.3%) of 1246 children sensitized in 1994 to 1996 compared with 11 (1.1%) of 981 sensitized 6 years ago (P = .001). Of 41 sensitized children in the current study, 10 reported a convincing clinical reaction to peanut, and 8 had positive oral challenge results, giving an overall estimate of peanut allergy of 1.5% (18/1246). Conclusions: Sensitization to peanut had increased between 1989 and 1994 to 1996. There was a strong but statistically nonsignificant trend for increase in reported peanut allergy. (J Allergy Clin Immunol 2002;110:784-9.)

Accidental exposures to peanut in a large cohort of Canadian children with peanut allergy

Clinical and translational allergy, 2015

We previously estimated that the annual rate of accidental exposure to peanut in 1411 children with peanut allergy, followed for 2227 patient-years, was 11.9% (95% CI, 10.6, 13.5). This cohort has increased to 1941 children, contributing 4589 patient-years, and we determined the annual incidence of accidental exposure, described the severity, management, location, and identified associated factors. Children with physician-confirmed peanut allergy were recruited from Canadian allergy clinics and allergy advocacy organizations from 2004 to May 2014. Parents completed questionnaires regarding accidental exposure to peanut over the preceding year. Five hundred and sixty-seven accidental exposures occurred in 429 children over 4589 patient-years, yielding an annual incidence rate of 12.4% (95% CI, 11.4, 13.4). Of 377 accidental exposures that were moderate or severe, only 109 (28.9%) sought medical attention and of these 109, only 40 (36.7%) received epinephrine. Of the 181 moderate/seve...

Inadvertent exposures in children with peanut allergy

Pediatric Allergy and Immunology, 2012

Peanut allergy is a potentially fatal condition affecting 1.2-1.8% of children in North America and the United Kingdom (1-4), and it has been implicated in 55% of food allergyrelated deaths in the United States (5). The amount of peanut triggering a reaction is often minimal (6, 7), and resolution rates range from 18.3% to 21.5% (8, 9). Therefore, for the majority, peanut allergy is lifelong and a source of considerable anxiety (10). Unfortunately, there is no well-established curative treatment, and management relies on avoidance (11). Patients and their caregivers must exercise extreme dietary vigilance by reading food labels and inquiring about ingredients. However, strict peanut avoidance is difficult, and accidental exposure remains a substantial concern. Studies have shown that the incidence of inadvertent exposure to peanut and nuts ranges from 3% to 75% in the United States and the United Kingdom (12-15). In 2006, we reported an annual incidence rate of accidental exposure to peanut of 14.3% among children in Quebec, Canada (15).

Allergy or tolerance in children sensitized to peanut: Prevalence and differentiation using component-resolved diagnostics

Journal of Allergy and Clinical Immunology, 2010

Background: Not all peanut-sensitized children develop allergic reactions on exposure. Objective: To establish by oral food challenge the proportion of children with clinical peanut allergy among those considered peanut-sensitized by using skin prick tests and/or IgE measurement, and to investigate whether component-resolved diagnostics using microarray could differentiate peanut allergy from tolerance. Methods: Within a population-based birth cohort, we ascertained peanut sensitization by skin tests and IgE measurement at age 8 years. Among sensitized children, we determined peanut allergy versus tolerance by oral food challenges. We used open challenge among children consuming peanuts (n 5 45); others underwent double-blind placebocontrolled challenge (n 5 34). We compared sensitization profiles between children with peanut allergy and peanuttolerant children by using a microarray with 12 pure components (major peanut and potentially cross-reactive components, including grass allergens). Results: Of 933 children, 110 (11.8%) were peanut-sensitized. Nineteen were not challenged (17 no consent). Twelve with a convincing history of reactions on exposure, IgE 15kUA/Land/orskintest15 kUA/L and/or skin test 15kUA/Land/orskintest8mm were considered allergic without challenge. Of the remaining 79 children who underwent challenge, 7 had $2 objective signs and were designated as having peanut allergy. We estimated the prevalence of clinical peanut allergy among sensitized subjects as 22.4% (95% CI, 14.8% to 32.3%). By using component-resolved diagnostics, we detected marked differences in the pattern of component recognition between children with peanut allergy (n 5 29; group enriched with 12 children with allergy) and peanuttolerant children (n 5 52). The peanut component Ara h 2 was the most important predictor of clinical allergy. Conclusion: The majority of children considered peanutsensitized on the basis of standard tests do not have peanut allergy. Component-resolved diagnostics may facilitate the diagnosis of peanut allergy. (J Allergy Clin Immunol 2010;125:191-7.)

Peanut allergy: Clinical and immunologic differences among patients from 3 different geographic regions

Journal of Allergy and Clinical Immunology, 2011

Background: Peanut allergy affects persons from various geographic regions where populations are exposed to different dietary habits and environmental pollens. Objective: We sought to describe the clinical and immunologic characteristics of patients with peanut allergy from 3 countries (Spain, the United States, and Sweden) using a molecular component diagnostic approach. Methods: Patients with peanut allergy from Madrid (Spain, n 5 50), New York (United States, n 5 30), Gothenburg, and Stockholm (both Sweden, n 5 35) were enrolled. Clinical data were obtained either from a specific questionnaire or gathered from chart reviews. IgE antibodies to peanut extract and the peanut allergens rAra h 1, 2, 3, 8 and 9, as well as to cross-reactive birch (rBet v 1) and grass (rPhl p 1, 5, 7, and 12) pollen allergens, were analyzed. Results: American patients frequently had IgE antibodies to rAra h 1 to 3 (56.7% to 90.0%) and often presented with severe symptoms. Spanish patients recognized these 3 recombinant peanut allergens less frequently (16.0% to 42.0%), were more often sensitized to the lipid transfer protein rAra h 9 (60.0%), and typically had peanut allergy after becoming allergic to other plant-derived foods. Swedish patients detected rAra h 1 to 3 more frequently than Spanish patients (37.1% to 74.3%) and had the highest sensitization rate to the Bet v 1 homologue rAra h 8 (65.7%), as well as to rBet v 1 (82.9%). Spanish and Swedish patients became allergic to peanut at 2 years or later, whereas the American children became allergic around 1 year of age. Conclusions: Peanut allergy has different clinical and immunologic patterns in different areas of the world. Allergen component diagnostics might help us to better understand this complex entity.

Diagnosis of Peanut Allergy in Preschool Children: The Impact of Skin Testing With a Novel Composition of Peanuts

Frontiers in Pediatrics, 2021

Peanut allergy is an increasing concern in younger children. Available bedside diagnostic tools, i.e., prick tests with commercial extracts or peanut-containing foods have only limited predictive values. In a cohort of preschoolers with both a history of allergic reactions and sensitization to peanut proteins, we aimed to characterize the impact of skin tests with a novel composition of peanuts LPP-MH. Almost one quarter (27/110) of preschool children, with a history of allergic reactions to peanuts and positive standard IgE-mediated tests for peanut allergy, can tolerate the reintroduction of peanut proteins into their diet after resolving their allergy and, thus, can avoid adverse health outcomes associated with the false diagnosis. In the younger age group, a quarter of peanut allergic children, display a relatively high threshold, potentially enabling an easier and safer oral immunotherapy protocol in this window of opportunity in childhood. The use of the novel diagnostic skin ...