Can we define a tolerable level of risk in food allergy? Report from a EuroPrevall/UK Food Standards Agency workshop.

BACKGROUND: There is an emerging consensus that, as with other risks in society, zero risk for food-allergic people is not a realistic or attainable option. Food allergy challenge data and new risk assessment methods offer the opportunity to develop quantitative limits for unintended allergenic ingredients which can be used in risk-based approaches. However, a prerequisite to their application is defining a tolerable level of risk. This requires a value judgement and is ultimately a 'societal' decision that has to involve all relevant stakeholders. OBJECTIVE: The aim of the workshop was to bring together key representatives from the stakeholders (regulators, food industry, clinical researchers and patients), and for the first time ever discuss the definition of a tolerable level of risk with regard to allergic reactions to food. RESULTS: The discussions revealed a consensus that zero risk was not a realistic option and that it is essential to address the current lack of agreed action levels for cross-contamination with allergens if food allergen management practice is to be improved. The discussions also indicated that it was difficult to define and quantify a tolerable level of risk, although both the clinical and the industry groups tried to do so. A consensus emerged that doing nothing was not a viable option, and there was a strong desire to take action to improve the current situation. CONCLUSIONS AND CLINICAL RELEVANCE: Two concrete actions were suggested: (1) Action levels should be derived from the data currently available. Different scenarios should be examined and further developed in an iterative process. On the basis of this work, a tolerable level of risk should be proposed. (2) 'One-dose' clinical trial with a low challenge dose should be performed in multiple centres to provide additional information about the general applicability of dose-distribution models and help validate the threshold levels derived.

Fatalities due to anaphylactic reactions to foods.

Fatal anaphylactic reactions to foods are continuing to occur, and better characterization might lead to better prevention. The objective of this report is to document the ongoing deaths and characterize these fatalities. We analyzed 32 fatal cases reported to a national registry, which was established by the American Academy of Allergy, Asthma, and Immunology, with the assistance of the Food Allergy and Anaphylaxis Network, and for which adequate data could be collected. Data were collected from multiple sources including a structured questionnaire, which was used to determine the cause of death and associated factors. The 32 individuals could be divided into 2 groups. Group 1 had sufficient data to identify peanut as the responsible food in 14 (67%) and tree nuts in 7 (33%) of cases. In group 2 subjects, 6 (55%) of the fatalities were probably due to peanut, 3 (27%) to tree nuts, and the other 2 cases were probably due to milk and fish (1 [9%] each). The sexes were equally affected; most victims were adolescents or young adults, and all but 1 subject were known to have food allergy before the fatal event. In those subjects for whom data were available, all but 1 was known to have asthma, and most of these individuals did not have epinephrine available at the time of their fatal reaction. Fatalities due to ingestion of allergenic foods in susceptible individuals remain a major health problem. In this series, peanuts and tree nuts accounted for more than 90% of the fatalities. Improved education of the profession, allergic individuals, and the public will be necessary to stop these tragedies.

The impact of childhood food allergy on quality of life.

BACKGROUND: Food allergy affects >6% of children, but the impact of this disease on health-related quality of life has not been well studied. METHODS: Parental perceptions of physical and psychosocial functioning were measured with the Children's Health Questionnaire (CHQ-PF50). This tool and an additional allergy-related questionnaire were sent to 400 members of the Food Allergy and Anaphylaxis Network with children aged 5 to 18, an age group on which the tool has been validated. RESULTS: Surveys were completed by 253 parents (63%). The mean age of the food-allergic children was 10.8 years (range, 5 to 18 yrs); 59% were male. Sixty-eight percent were allergic to one or two foods, the remainder to more than two foods. Concomitant chronic atopic diseases included: asthma with atopic dermatitis (33%), atopic dermatitis alone (13%), asthma alone (33%), and 21% had neither asthma nor atopic dermatitis. In comparison to previously established norms, the families scored significantly lower (more than 10 scale score points lower and P < 0.0001) for general health perception (GH), emotional impact on the parent (PE), and limitation on family activities (FA). Associated atopic disease, influenced primarily by those with both asthma and atopic dermatitis, accounted for a significant reduction in the GH scale (analysis of variance, P = 0.0001), but not for measures of PE and FA. Within the study group, food-allergic individuals with several (more than two) food allergies had significantly lower (P < 0.05) scores for 7 of 12 scales compared with individuals with few (one or two) food allergies. However, those with one or two food allergies scored significantly lower (P < 0.0001) than established norms on scales for GH, PE, and FA. CONCLUSIONS: Childhood food allergy has a significant impact on GH, PE, and FA. Factors that influence reductions in these scales include associated atopic disease and the number of foods being avoided.

Prevalence of peanut and tree nut allergy in the US determined by a random digit dial telephone survey.

BACKGROUND: Allergy to peanuts and tree nuts (TNs) is one of the leading causes of fatal and near-fatal food-induced allergic reactions. These allergies can be lifelong and appear to be increasing in prevalence. Despite the seriousness of these allergies, the prevalence of peanut and TN allergy in the general population is unknown. OBJECTIVE: We sought to determine the prevalence of peanut and TN allergy among the general population of the United States. METHODS: We used a nationwide, cross-sectional, random digit dial telephone survey with a standardized questionnaire. RESULTS: A total of 4374 households contacted by telephone participated (participation rate, 67%), representing 12,032 individuals. Peanut or TN allergy was self-reported in 164 individuals (1.4%; 95% confidence interval [CI], 1.2%-1.6%) in 151 households (3.5%; 95% CI, 2.9%-4.0%). The prevalence of reported allergy in adults (1.6%) was higher than that found in children under 18 years of age (0.6%). In 131 individuals, details of the reactions were obtained. When applying criteria requiring reactions to be typical of IgE-mediated reactions (hives, angioedema, wheezing, throat tightness, vomiting, and diarrhea) within an hour of ingestion, 10% of these subjects were excluded. Among the remaining 118 subjects, allergic reactions involved 1 organ system (skin, respiratory, or gastrointestinal systems) in 50 subjects, 2 in 45 subjects, and all 3 in 23 subjects. Forty-five percent of these 118 respondents reported more than 5 lifetime reactions. Only 53% of these 118 subjects ever saw a physician for the allergic reaction, and only 7% had self-injectable epinephrine available at the time of the interview. The prevalence of peanut and TN allergy was adjusted by assuming that 10% of the remaining 33 subjects without a description of their reactions would also be excluded and correcting for a 7% false-positive rate for the survey instrument. A final "corrected" prevalence estimate of 1.1% (95% CI, 1.0%-1.4%) was obtained. CONCLUSIONS: Peanut and/or TN allergy affects approximately 1.1% of the general population, or about 3 million Americans, representing a significant health concern. Despite the severity of reactions, about half of the subjects never sought an evaluation by a physician, and only a few had epinephrine available for emergency use.

A voluntary registry for peanut and tree nut allergy: characteristics of the first 5149 registrants.

BACKGROUND: A voluntary registry of individuals with peanut and/or tree nut allergy was established in 1997 to learn more about these food allergies. OBJECTIVE: The purpose of this study was to elucidate a variety of features of peanut and tree nut allergy among the first 5149 registry participants. METHODS: The registry was established through use of a structured questionnaire distributed to all members of the Food Allergy and Anaphylaxis Network and to patients by allergists. Parental surrogates completed the forms for children under the age of 18 years. RESULTS: Registrants were primarily children (89% of registrants were younger than 18 years of age; the median age was 5 years), reflecting the membership of the Network. Isolated peanut allergy was reported by 3482 registrants (68%), isolated tree nut allergy by 464 (9%), and allergy to both foods by 1203 (23%). Registrants were more likely to have been born in October, November, or December (odds ratio, 1.2; 95% CI, 1.18-1.23; P <.0001). The median age of reaction to peanut was 14 months, and the median age of reaction to tree nuts was 36 months; these represented the first known exposure for 74% and 68% of registrants, respectively. One half of the reactions involved more than 1 organ system, and more than 75% required treatment, frequently from medical personnel. Registrants with asthma were more likely than those without asthma to have severe reactions (33% vs 21%; P <.0001). In comparison with initial reactions, subsequent reactions due to accidental ingestion were more severe, more common outside the home, and more likely to be treated with epinephrine. CONCLUSIONS: Allergic reactions to peanut and tree nut are frequently severe, often occur on the first known exposure, and can become more severe over time.