Background Currently, the longitudinal validity (validity over time) and responsiveness (ability to measure change over time) of the Food Allergy Quality of Life Questionnaire–Adult Form (FAQLQ-AF), ...the Food Allergy Quality of Life Questionnaire–Teenager Form (FAQLQ-TF), and the Food Allergy Quality of Life Questionnaire–Child Form (FAQLQ-CF) are unknown. Additionally, the self-reported impact of a double-blind, placebo-controlled food challenge (DBPCFC) on health-related quality of life (HRQL) in adults (≥18 years of age), adolescents (13-17 years of age), and children (8-12 years of age) is unknown. Objective The aims of this study were to assess the longitudinal validity and responsiveness of the FAQLQ-AF, FAQLQ-TF, and FAQLQ-CF and to assess the impact of a DBPCFC on HRQL. Methods Two hundred twenty-one participants suspected of food allergy were included from Dutch allergy centers. Participants undergoing a DBPCFC (experimental group) completed the FAQLQ and Food Allergy Independent Measure (FAIM) 1 month before (baseline) and 6 months after (follow-up) a DBPCFC. Participants not undergoing a DBPCFC (control group) completed the questionnaire package twice with a 7-month interval. Results HRQL scores improved after a DBPCFC, with greater improvements in HRQL scores after a negative outcome (food allergy ruled out) than a positive outcome (food allergy confirmed), demonstrating responsiveness of the FAQLQs. Significant correlations were shown between the change (follow-up minus baseline) in FAQLQ and FAIM scores supporting longitudinal validity of these questionnaires: FAQLQ-AF (Pearson correlation coefficient = 0.71, P < .001), FAQLQ-TF (Pearson correlation coefficient = 0.35, P = .018), and FAQLQ-CF (Pearson correlation coefficient = 0.51, P < .001). Conclusions Our findings demonstrate the longitudinal validity and responsiveness of the FAQLQs. Greater improvements in HRQL scores were shown after a negative outcome than after a positive outcome.
Background Food allergy can affect health-related quality of life (HRQL). Currently, no validated, self-administered, disease-specific HRQL questionnaire for adolescents with food allergy exists. ...Objective We sought to develop and validate the Food Allergy Quality of Life Questionnaire–Teenager Form (FAQLQ-TF) in the Dutch language. Methods Ten adolescents (13-17 years) with food allergy were interviewed and generated 166 HRQL items. The most important items were identified by 51 adolescents with food allergy by using the clinical impact method, resulting in the FAQLQ-TF containing 28 items (score range: 1 “no impairment” to 7 “maximal impairment”). The FAQLQ-TF, the Food Allergy Independent Measure, and a generic HRQL questionnaire (CHQ-CF87) were sent to 98 adolescents with food allergy for cross-sectional validation of the FAQLQ-TF. Results Construct validity was assessed based on the correlation between the FAQLQ-TF and the Food Allergy Independent Measure (ρ = 0.57, P < .001). The FAQLQ-TF had excellent internal consistency (Cronbach α = .92) and discriminated between adolescents who differed in number of food allergies (1 vs >2 food allergies: total FAQLQ-TF score, 4.3 vs 3.5; P = 0.037) but did not discriminate between those who did or did not have reported anaphylaxis. The FAQLQ-TF correlated weakly with 6 of the 11 CHQ-CF87 scales, demonstrating convergent/discriminant validity. Conclusion The FAQLQ-TF is the first self-administered, disease-specific HRQL questionnaire for adolescents with food allergy. It has good construct validity and excellent internal consistency and discriminates between adolescents who differ in the number of food allergies. The FAQLQ-TF is short and easy to use and might therefore be a useful tool in clinical research.
Patients with indolent systemic mastocytosis (ISM) are at risk for severe anaphylactic reactions to yellow jacket (YJ) stings while demonstration of sensitization can be challenging because specific ...IgE (sIgE) levels are regularly below 0.35 kU
/L. The implication of missing YJ allergy is illustrated by a case of fatal anaphylaxis.
To explore the natural course of YJ venom allergy and the diagnostic accuracy and therapeutic consequence of YJ venom sIgE in patients with ISM.
All patients with ISM seen from 1981 to 2015 (n = 243) were evaluated on the number of YJ stings, reaction severity, and sensitivity and specificity of YJ venom sIgE. YJ venom allergic patients without mastocytosis served as control (n = 313).
A total of 153 patients with ISM were stung during adult life. The first systemic reaction was more often severe in patients with ISM than in patients without mastocytosis (69.9% vs 22.0%) and reactions recurred in 40 of 41 re-stung patients with ISM. ISM reactors showed lower YJ venom sIgE levels than nonmastocytosis reactors (0.61 vs 4.83 kU
/L; P < .001) and asymptomatic sensitization was exceedingly rare. In ISM the current clinical threshold of 0.35 kU
/L yields a sensitivity and specificity of 77.6% and 87.5%, respectively. The optimal diagnostic accuracy is achieved at 0.17 kU
/L (sensitivity, 83.6%; specificity, 85.0%).
The high rate of severe reactions and the fatal case underscore the importance of adequate diagnostic sensitivity of sIgE in patients with ISM. The sensitivity of sIgE can be ameliorated by lowering the threshold to 0.17 kU
/L, retaining good specificity. We recommend sIgE screening in all patients with ISM and discussing immunotherapy when YJ venom sIgE exceeds 0.17 kU
/L.
Food allergy can impair health-related quality of life (HRQL). Food Allergy Quality of Life Questionnaires (FAQLQs) have been developed and validated, including an adult form (FAQLQ-AF). HRQL has ...not, to date, been measured across different European countries using a uniform methodology.
To translate and validate the FAQLQ-AF for use in 8 European countries (Iceland, The Netherlands, Poland, France, Spain, Italy, Greece, and Sweden).
The English FAQLQ-AF was translated, back-translated, and compared for use in the 8 relevant European languages. Adults with a perceived food allergy were recruited from outpatient departments and through a community survey. Participants completed the FAQLQ-AF, the Food Allergy Independent Measure, and questions concerning participants' characteristics. Validity of the FAQLQ-AF was analyzed for use in the 8 countries.
The FAQLQ-AF had strong construct validity (r > 0.59) and an excellent internal consistency (Cronbach α > 0.95) in all countries. Total FAQLQ-AF scores (range 3.2-5.0) were significantly different across participating countries.
The FAQLQ-AF is a suitable and valid instrument for measuring HRQL in food-allergic adults in Iceland, The Netherlands, Poland, France, Spain, Italy, Greece, and Sweden. The impact of food allergy on HRQL seems to differ among adults from the 8 participating European countries.
...although some distribution variability did occur for peanut when comparing adults and children, the predicted ED05 doses were not different for children versus adults with peanut allergy.
In an article reviewing the status of gastrointestinal allergy in the New England Journal of Medicine in 1949, Ingelfinger et al1 decried the reliance on patients' "incrimination" of specific foods, ...outcome of trial diets, or association of abdominal complaints with symptoms believed to be allergic in making the diagnosis of food allergy. Recently, the National Institutes of Health-sponsored expert panel "Guidelines for the diagnosis and management of food allergy," reaffirmed the utility of the DBPCFC for diagnosing food allergy after an extensive review of the current literature.11 However, the expert panel noted that open or single-blind challenges could also be acceptable when the challenge outcome is negative or when objective symptoms are elicited that exactly recapitulate the history of the reaction.
Background For most allergenic foods, insufficient threshold dose information within the population restricts the advice on levels of unintended allergenic foods which should trigger precautionary ...labeling on prepackaged foods. Objective We wanted to derive threshold dose distributions for major allergenic foods and to elaborate the protein doses at which a proportion of the allergic population is likely to respond. Methods For 7 allergenic foods double-blind, placebo-controlled food challenges (DBPCFCs) with a positive outcome for allergic reactions were selected from the clinical database of children routinely tested to diagnose food allergy at the University Medical Center Groningen. For each allergen 2 population threshold distributions were determined with the individual minimal eliciting dose and the preceding dose of each DBPCFC for objective symptoms and any symptom (either subjective or objective). Results Individual positive DBPCFCs were available for peanut (n = 135), cow’s milk (n = 93), hen’s egg (n = 53), hazelnut (n = 28), and cashew nut (n = 31). Fewer children were challenged with soy (n = 10) or walnut (n = 13). Threshold dose distributions showed a good statistical and visual fit. The protein dose at which 5% of the allergic population is likely to respond with objective reactions was 1.6 mg for peanut, 1.1 mg for cow’s milk, 1.5 mg for hen’s egg, 7.4 mg for cashew nut, and 0.29 mg for hazelnut. Thresholds for any symptom were on average 2 to 6 times lower than for objective symptoms. The 95% upper and lower confidence intervals of the threshold distributions were overlapping. The peanut threshold distribution on objective symptoms was similar to the distribution of another European center. Conclusions Threshold distribution curves and eliciting doses are a powerful tool to compare different allergenic foods and for informing policy on precautionary labeling.
Summary Background The effects of a restricted elimination diet in children with attention-deficit hyperactivity disorder (ADHD) have mainly been investigated in selected subgroups of patients. We ...aimed to investigate whether there is a connection between diet and behaviour in an unselected group of children. Methods The Impact of Nutrition on Children with ADHD (INCA) study was a randomised controlled trial that consisted of an open-label phase with masked measurements followed by a double-blind crossover phase. Patients in the Netherlands and Belgium were enrolled via announcements in medical health centres and through media announcements. Randomisation in both phases was individually done by random sampling. In the open-label phase (first phase), children aged 4–8 years who were diagnosed with ADHD were randomly assigned to 5 weeks of a restricted elimination diet (diet group) or to instructions for a healthy diet (control group). Thereafter, the clinical responders (those with an improvement of at least 40% on the ADHD rating scale ARS) from the diet group proceeded with a 4-week double-blind crossover food challenge phase (second phase), in which high-IgG or low-IgG foods (classified on the basis of every child's individual IgG blood test results) were added to the diet. During the first phase, only the assessing paediatrician was masked to group allocation. During the second phase (challenge phase), all persons involved were masked to challenge allocation. Primary endpoints were the change in ARS score between baseline and the end of the first phase (masked paediatrician) and between the end of the first phase and the second phase (double-blind), and the abbreviated Conners' scale (ACS) score (unmasked) between the same timepoints. Secondary endpoints included food-specific IgG levels at baseline related to the behaviour of the diet group responders after IgG-based food challenges. The primary analyses were intention to treat for the first phase and per protocol for the second phase. INCA is registered as an International Standard Randomised Controlled Trial, number ISRCTN 76063113. Findings Between Nov 4, 2008, and Sept 29, 2009, 100 children were enrolled and randomly assigned to the control group (n=50) or the diet group (n=50). Between baseline and the end of the first phase, the difference between the diet group and the control group in the mean ARS total score was 23·7 (95% CI 18·6–28·8; p<0·0001) according to the masked ratings. The difference between groups in the mean ACS score between the same timepoints was 11·8 (95% CI 9·2–14·5; p<0·0001). The ARS total score increased in clinical responders after the challenge by 20·8 (95% CI 14·3–27·3; p<0·0001) and the ACS score increased by 11·6 (7·7–15·4; p<0·0001). In the challenge phase, after challenges with either high-IgG or low-IgG foods, relapse of ADHD symptoms occurred in 19 of 30 (63%) children, independent of the IgG blood levels. There were no harms or adverse events reported in both phases. Interpretation A strictly supervised restricted elimination diet is a valuable instrument to assess whether ADHD is induced by food. The prescription of diets on the basis of IgG blood tests should be discouraged. Funding Foundation of Child and Behaviour, Foundation Nuts Ohra, Foundation for Children's Welfare Stamps Netherlands, and the KF Hein Foundation.
Atopic dermatitis (AD) and food allergy frequently coexist in children.
To examine the association between food allergy and AD.
Between 2001 and 2011, children referred to our tertiary care center ...underwent double-blind, placebo-controlled food challenges (DBPCFCs) for one or more suspected food allergies as part of regular care. Immediate reactions were observed and recorded by allergy nursing staff, whereas late reactions were ascertained by semistructured telephone interview 48 hours after challenge. To test to which degree specific IgE results were predictive in the outcome of DBPCFCs in children with and without (previous and current) AD, logistic regression analysis was performed.
A total of 1186 DBPCFCs were studied. Sensitization to foods occurred significantly more often in children with previous AD. The association between specific IgE results and the outcome of DBPCFCs was significant for children with and without (previous and current) AD but stronger for children without current AD. The positivity rate of DBPCFCs in children with mild, moderate, and severe AD was 53.3%, 51.7%, and 100%, respectively. Children with AD and a history of worsening AD as their only symptom reacted as often to placebo as to challenge food.
Children with current AD are more frequently asymptomatically sensitized to the foods in question than those without AD. In addition, children suspected of food allergy should be considered for testing, regardless of the severity of their AD. Our results suggest that children with exacerbation of AD in the absence of other allergic symptoms are unlikely to be food allergic.
