International survey on growth indices and impacting factors in children with food allergies.

BACKGROUND: Elimination diets required for the management of food allergies increase the risk for poor growth in children. Currently, no worldwide data exist on this topic and limited published data exist on the impact of atopic comorbidity, type of allergy and foods eliminated on growth. We therefore set out to perform a worldwide survey on growth and impacting factors in food allergic children. METHODS: A prospective growth survey was performed of children (aged 0-16 years) on an elimination diet with confirmed immunoglobulin (Ig)E and non-IgE mediated food allergies. Data collected included: weight-for-age, weight-for-height, height-for-age, head circumference, body mass index, type of food allergy and eliminated foods, allergic comorbidities and replacement milk/breast milk. Multivariable regression analysis was used to establish factors that affected growth. RESULTS: Data from 430 patients from twelve allergy centres were analysed: median age at diagnosis and data collection was 8 months and 23 months, respectively. Pooled data indicated that 6% were underweight, 9% were stunted, 5% were undernourished and 8% were overweight. Cow's milk elimination lead to a lower weight-for-height Z-scores than other food eliminations and mixed IgE and non-IgE mediated allergy had lower height-for-age Z-scores than IgE mediated allergy. Children with only non-IgE mediated allergies had lower weight-for-height and body mass index. Atopic comorbidities did not impact on growth. CONCLUSIONS: Stunting is more common in children with food allergies than low weight. Children particularly at risk of poor growth are those with non-IgE and mixed IgE and non-IgE mediated allergies, as well as those with cow's milk allergy.

First successful reduction of clinical allergenicity of food by genetic modification: Mal d 1-silenced apples cause fewer allergy symptoms than the wild-type cultivar.

BACKGROUND: Genetic modification of allergenic foods such as apple has the potential to reduce their clinical allergenicity, but this has never been studied by oral challenges in allergic individuals. METHODS: We performed oral food challenges in 21 apple-allergic individuals with Elstar apples which had undergone gene silencing of the major allergen of apple, Mal d 1, by RNA interference. Downregulation of Mal d 1 gene expression in the apples was verified by qRT-PCR. Clinical responses to the genetically modified apples were compared to those seen with the wild-type Elstar using a visual analogue scale (VAS). RESULTS: Gene silencing produced two genetically modified apple lines expressing Mal d 1.02 and other Mal d 1 gene mRNA levels which were extensively downregulated, that is only 0.1-16.4% (e-DR1) and 0.2-9.9% (e-DR2) of those of the wild-type Elstar, respectively. Challenges with these downregulated apple lines produced significantly less intense maximal symptoms to the first dose (Vmax1) than with Elstar (Vmax1 Elstar 3.0 mm vs 0.0 mm for e-DR1, P = 0.017 and 0.0 mm for e-DR2, P = 0.043), as well as significantly less intense mean symptoms per dose (meanV/d) than with Elstar (meanV/d Elstar 2.2 mm vs 0.2 mm for e-DR1, P = 0.017 and 0.0 mm for e-DR2, P = 0.043). Only one subject (5%) remained symptom-free when challenged with the Elstar apple, whereas 43% did so with e-DR1 and 63% with e-DR2. CONCLUSION: These data show that mRNA silencing of Mal d 1 results in a marked reduction of Mal d 1 gene expression in the fruit and reduction of symptoms when these apples are ingested by allergic subjects. Approximately half of the subjects developed no symptoms whatsoever, and virtually all subjects wished to consume the apple again in the future.

The epidemiology of food allergy in Europe: a systematic review and meta-analysis.

Food allergy (FA) is an important atopic disease although its precise burden is unclear. This systematic review aimed to provide recent, up-to-date data on the incidence, prevalence, time trends, and risk and prognostic factors for FA in Europe. We searched four electronic databases, covering studies published from 1 January 2000 to 30 September 2012. Two independent reviewers appraised the studies and qualified the risk of bias using the Critical Appraisal Skills Programme tool. Seventy-five eligible articles (comprising 56 primary studies) were included in a narrative synthesis, and 30 studies in a random-effects meta-analysis. Most of the studies were graded as at moderate risk of bias. The pooled lifetime and point prevalence of self-reported FA were 17.3% (95% CI: 17.0-17.6) and 5.9% (95% CI: 5.7-6.1), respectively. The point prevalence of sensitization to ≥1 food as assessed by specific IgE was 10.1% (95% CI: 9.4-10.8) and skin prick test 2.7% (95% CI: 2.4-3.0), food challenge positivity 0.9% (95% CI: 0.8-1.1). While the incidence of FA appeared stable over time, there was some evidence that the prevalence may be increasing. There were no consistent risk or prognostic factors for the development or resolution of FA identified, but sex, age, country of residence, familial atopic history, and the presence of other allergic diseases seem to be important. Food allergy is a significant clinical problem in Europe. The evidence base in this area would benefit from additional studies using standardized, rigorous methodology; data are particularly required from Eastern and Southern Europe.

The diagnosis of food allergy: a systematic review and meta-analysis.

BACKGROUND: We investigated the accuracy of tests used to diagnose food allergy. METHODS: Skin prick tests (SPT), specific-IgE (sIgE), component-resolved diagnosis and the atopy patch test (APT) were compared with the reference standard of double-blind placebo-controlled food challenge. Seven databases were searched and international experts were contacted. Two reviewers independently identified studies, extracted data, and used QUADAS-2 to assess risk of bias. Where possible, meta-analysis was undertaken. RESULTS: Twenty-four (2831 participants) studies were included. For cows' milk allergy, the pooled sensitivities were 53% (95% CI 33-72), 88% (95 % CI 76-94), and 87% (95% CI 75-94), and specificities were 88% (95% CI 76-95), 68% (95% CI 56-77), and 48% (95% CI 36-59) for APT, SPT, and sIgE, respectively. For egg, pooled sensitivities were 92% (95% CI 80-97) and 93% (95% CI 82-98), and specificities were 58% (95% CI 49-67) and 49% (40-58%) for skin prick tests and specific-IgE. For wheat, pooled sensitivities were 73% (95% CI 56-85) and 83% (95% CI 69-92), and specificities were 73% (95% CI 48-89) and 43% (95% CI 20-69%) for SPT and sIgE. For soy, pooled sensitivities were 55% (95% CI 33-75) and 83% (95% CI 64-93), and specificities were 68% (95% CI 52-80) and 38% (95% CI 24-54) for SPT and sIgE. For peanut, pooled sensitivities were 95% (95% CI 88-98) and 96% (95% CI 92-98), and specificities were 61% (95% CI 47-74), and 59% (95% CI 45-72) for SPT and sIgE. CONCLUSIONS: The evidence base is limited and weak and is therefore difficult to interpret. Overall, SPT and sIgE appear sensitive although not specific for diagnosing IgE-mediated food allergy.

Acute and long-term management of food allergy: systematic review.

BACKGROUND: Allergic reactions to food can have serious consequences. This systematic review summarizes evidence about the immediate management of reactions and longer-term approaches to minimize adverse impacts. METHODS: Seven bibliographic databases were searched from their inception to September 30, 2012, for systematic reviews, randomized controlled trials, quasi-randomized controlled trials, controlled clinical trials, controlled before-and-after and interrupted time series studies. Experts were consulted for additional studies. There was no language or geographic restrictions. Two reviewers critically appraised the studies using the appropriate tools. Data were not suitable for meta-analysis due to heterogeneity so were narratively synthesized. RESULTS: Eighty-four studies were included, but two-thirds were at high risk of potential bias. There was little evidence about acute management for non-life-threatening reactions. H1-antihistamines may be of benefit, but this evidence was in part derived from studies on those with cross-reactive birch pollen allergy. Regarding long-term management, avoiding the allergenic food or substituting an alternative was commonly recommended, but apart from for infants with cow's milk allergy, there was little high-quality research on this management approach. To reduce symptoms in children with cow's milk allergy, there was evidence to recommend alternatives such as extensively hydrolyzed formula. Supplements such as probiotics have not proved helpful, but allergen-specific immunotherapy may be disease modifying and therefore warrants further exploration. CONCLUSIONS: Food allergy can be debilitating and affects a significant number of people. However, the evidence base about acute and longer-term management is weak and needs to be strengthened as a matter of priority.

EAACI food allergy and anaphylaxis guidelines: managing patients with food allergy in the community.

The European Academy of Allergy and Clinical Immunology (EAACI) Food Allergy and Anaphylaxis Guidelines, managing patients with food allergy (FA) in the community, intend to provide guidance to reduce the risk of accidental allergic reactions to foods in the community. This document is intended to meet the needs of early-childhood and school settings as well as providers of non-prepackaged food (e.g., restaurants, bakeries, takeaway, deli counters, and fast-food outlets) and targets the audience of individuals with FA, their families, patient organizations, the general public, policymakers, and allergists. Food allergy is the most common trigger of anaphylaxis in the community. Providing children and caregivers with comprehensive information on food allergen avoidance and prompt recognition and management of allergic reactions are of the utmost importance. Provision of adrenaline auto-injector devices and education on how and when to use these are essential components of a comprehensive management plan. Managing patients at risk of anaphylaxis raises many challenges, which are specific to the community. This includes the need to interact with third parties providing food (e.g., school teachers and restaurant staff) to avoid accidental exposure and to help individuals with FA to make safe and appropriate food choices. Education of individuals at risk and their families, their peers, school nurses and teachers as well as restaurant and other food retail staff can reduce the risk of severe/fatal reactions. Increased awareness among policymakers may improve decision-making on legislation at local and national level.

Anaphylaxis: guidelines from the European Academy of Allergy and Clinical Immunology.

Anaphylaxis is a clinical emergency, and all healthcare professionals should be familiar with its recognition and acute and ongoing management. These guidelines have been prepared by the European Academy of Allergy and Clinical Immunology (EAACI) Taskforce on Anaphylaxis. They aim to provide evidence-based recommendations for the recognition, risk factor assessment, and the management of patients who are at risk of, are experiencing, or have experienced anaphylaxis. While the primary audience is allergists, these guidelines are also relevant to all other healthcare professionals. The development of these guidelines has been underpinned by two systematic reviews of the literature, both on the epidemiology and on clinical management of anaphylaxis. Anaphylaxis is a potentially life-threatening condition whose clinical diagnosis is based on recognition of a constellation of presenting features. First-line treatment for anaphylaxis is intramuscular adrenaline. Useful second-line interventions may include removing the trigger where possible, calling for help, correct positioning of the patient, high-flow oxygen, intravenous fluids, inhaled short-acting bronchodilators, and nebulized adrenaline. Discharge arrangements should involve an assessment of the risk of further reactions, a management plan with an anaphylaxis emergency action plan, and, where appropriate, prescribing an adrenaline auto-injector. If an adrenaline auto-injector is prescribed, education on when and how to use the device should be provided. Specialist follow-up is essential to investigate possible triggers, to perform a comprehensive risk assessment, and to prevent future episodes by developing personalized risk reduction strategies including, where possible, commencing allergen immunotherapy. Training for the patient and all caregivers is essential. There are still many gaps in the evidence base for anaphylaxis.

No matrix effect in double-blind, placebo-controlled egg challenges in egg allergic children.

BACKGROUND: Diagnostic and accidental food allergic reactions may be modified by the matrix containing the allergenic food. Previous studies of double-blind, placebo-controlled food challenges (DBPCFCs) with peanut found an effect of the fat content of the challenge matrix on the severity of the challenge reactions. OBJECTIVE: The aim of this study was to examine whether the fat content of the food matrix is related to eliciting dose and reaction severity in DBPCFCs with heated hen's egg. METHODS: Sensitized egg allergic children (n = 59) undergoing DBPCFCs with egg as a routine diagnostic procedure in our tertiary care centre were evaluated retrospectively. Three different recipes were used for the food matrix: vanilla pudding, pancake and minced meat, containing 22.8%, 31.9% and 52.7% fat (weighted average), respectively. The eliciting dose (i.e. the highest cumulative dose to which the child reacted) was analyzed by Kaplan-Meier log-rank statistic and by Cox regression. Reaction severity was quantified by using an index (range 1-12) and was analysed by multiple linear regression analysis. RESULTS: The overall influence of type of recipe on eliciting dose was not significant (P = 0.12). The rate of response to minced meat (with the highest fat content) was not significantly different from pudding [HR = 0.61 (0.26-1.45, P = 0.26) or pancake (HR = 1.41 (0.50-3.99), P = 0.52] after adjustment for confounders. The type of recipe did not influence the severity of the challenge reaction. The severity of the challenge reaction for minced meat compared to pudding and pancake was 1.06 (0.52-2.16), P = 0.87 and 0.81 (0.32-2.01), P = 0.64, respectively, after correction for confounders. CONCLUSION AND CLINICAL RELEVANCE: In contrast to similar research with peanut, no significant influence of the fat content of the matrix was found on the eliciting dose or severity of the reaction in 59 DBPCFCs with hen's egg. Matrix fat content differences comparable to those reported here may not be an important co-determinant of reaction severity for all allergenic foods.

Where to prick the apple for skin testing?

Mal d 1 is not equally distributed over the apple. We aimed to examine the influence of the location of pricking in the apple on prick-to-prick skin prick test (PTP) results. PTPs were performed in autumn 2007 and spring 2008, before the birch pollen season, in 32 Dutch adults with symptoms of oral allergy to fresh apple, using apples harvested in autumn 2007. PTPs with fresh intact and unpeeled Pink Lady, Golden Delicious, Elise, Santana and Modi apples were performed using material obtained from approximately 2 cm near the stalk (top), and the middle region. All PTP responses were greater when performed with apple material near the stalk than from the middle region. In 2007, these differences were statistically significant for Pink Lady, Golden Delicious and Elise, and in 2008, for Pink Lady and Modi. When performing PTPs, the apple should be pricked near the stalk rather than in the middle.

Birch pollen sensitization with cross-reactivity to food allergens predominates in adults with eosinophilic esophagitis.

EoE patients show variable sensitization patterns to food and aeroallergens. The value of allergy testing in adult EoE patients is unclear. Component-resolved diagnosis (CRD) may offer additional insights into sensitization patterns. The aim of this study was to characterize sensitization patterns in adult EoE patients using CRD. Serum from 76 patients (17 female), age 38.6 ± 1.5 years, was analyzed for reactivity to 112 different allergen components using an immuno-solid-phase allergen chip (ISAC). We observed any sensitization in 59 patients (78%), of which 54 patients were polysensitized. Aeroallergen sensitization, mostly against components of grass or tree pollen, or house dust mite, was observed in 74% of the patients. Birch pollen (rBet v 1) sensitization with cross-reactivity to food allergen components was observed in 30 patients (39%). In conclusion, food sensitizations in EoE patients are mainly caused by cross-reactivity to food allergens after primary birch pollen sensitization. Pollen and food sensitizations may cause or maintain esophageal inflammation in EoE patients. CRD provides more insight into sensitization patterns, identifies additional food allergen sensitizations and might be useful to direct dietary therapy in EoE.

The epidemiology of anaphylaxis in Europe: a systematic review.

BACKGROUND: Anaphylaxis is an acute, potentially fatal, multi-organ system, allergic reaction caused by the release of chemical mediators from mast cells and basophils. Uncertainty exists around epidemiological measures of incidence and prevalence, risk factors, risk of recurrence, and death due to anaphylaxis. This systematic review aimed to (1) understand and describe the epidemiology of anaphylaxis and (2) describe how these characteristics vary by person, place, and time. METHODS: Using a highly sensitive search strategy, we identified systematic reviews of epidemiological studies, descriptive and analytical epidemiological investigations, and studies involving analysis of routine data. RESULTS: Our searches identified a total of 5,843 potentially eligible studies, of which 49 satisfied our inclusion criteria. Of these, three were suitable for pooled estimates of prevalence. The incidence rates for all-cause anaphylaxis ranged from 1.5 to 7.9 per 100,000 person-years. These data indicated that an estimated 0.3% (95% CI 0.1-0.5) of the population experience anaphylaxis at some point in their lives. Food, drugs, stinging insects, and latex were the most commonly identified triggers. CONCLUSIONS: Anaphylaxis is a common problem, affecting an estimated 1 in 300 of the European population at some time in their lives. Future research needs to focus on better understanding of the trends across Europe and identifying those most likely to experience fatal reactions.

Additional indications for the low allergenic properties of the apple cultivars Santana and Elise.

Patients with Oral Allergy Syndrome (OAS) to fresh apple may tolerate low allergenic apple cultivars. We aimed to investigate if the low allergenic properties of Elise and Santana, as previously identified in a Dutch population, could be generalised within North West Europe within the birch pollen region with regard to both the prevalence and degree of sensitization. Prick-to-prick tests (PTP) were performed in eighty-five adult patients with OAS to fresh apple in Great Britain, Switzerland and Northern Italy, before the birch pollen season, using the putatively low allergenic apple cultivars Elise, Santana, Granny Smith, Modi and Mcintosh, as well as the putatively high allergenic apple cultivars Golden Delicious and Kanzi. No significant differences in percentages of negative responses of PTPs were found between the three countries. Negative responses did not differ from negative responses to the different apple cultivars we previously found in 2006/2007 in the Netherlands. The size of the PTPs of all apple cultivars tested were correlated to the size of the skin prick tests with birch pollen. These results add to the indications for the low allergenic properties of the low allergenic apple cultivars Santana and Elise, as the number of negative responses were reproducible in three countries within the birch pollen region and were similar to previous results in the Netherlands. These results justify oral challenge studies with Elise and Santana within the birch pollen region, to establish the low allergenic properties for the benefit for apple allergic consumers for definite conclusions.

Online version of the food allergy quality of life questionnaire-adult form: validity, feasibility and cross-cultural comparison.

BACKGROUND: Food-allergic reactions occur in 3-4% of the adult population in Western countries. It has been shown that food allergy may 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). These questionnaires may be particularly useful for cross-cultural comparisons. OBJECTIVES: The aims of this study were to translate the FAQLQ-AF from Dutch into English and validate an online version in the United States. Additionally, HRQL of American and Dutch food-allergic adults was compared. METHODS: The Dutch FAQLQ-AF was translated into English as set out by the World Health Organization and converted to an electronic online format. Participants (food allergic American adults) were recruited through the 'Food Allergy and Anaphylaxis Network' website and completed the questionnaire online. Construct validity, internal consistency, discriminative ability and feasibility were analysed. A cross-cultural comparison was made using the Dutch FAQLQ-AF scores. RESULTS: Data from 180 American participants were analysed. The online FAQLQ-AF had a good construct validity (correlation with FAIM: ρ=0.72; P<0.001), internal consistency (Cronbach's α=0.95) and was discriminative for 'anaphylaxis' vs. 'no anaphylaxis' and 'number of food allergies'. The most striking finding was a significantly greater impairment in HRQL in the American participants, as compared with their Dutch counterparts (the total FAQLQ-AF scores were 4.3 vs. 3.5, respectively; P<0.001, where 1 signifies no impairment and 7 signifies extreme impairment in HRQL). CONCLUSIONS AND CLINICAL RELEVANCE: The online American FAQLQ-AF is a valid instrument to measure HRQL in food-allergic patients in the United States. Additionally, HRQL of American food-allergic adults may be more impaired than Dutch food-allergic adults. The FAQLQ-AF can now be used to determine the HRQL in American food-allergic adults and can assist clinicians in optimizing management strategies for food-allergic patients.

Validation of novel recipes for double-blind, placebo-controlled food challenges in children and adults.

BACKGROUND: In double-blind, placebo-controlled food challenges (DBPCFCs), the use of challenge materials in which blinding is validated is a prerequisite for obtaining true blinded conditions during the test procedure. Therefore, the aim of this study was to enlarge the available range of validated recipes for DBPCFCs to facilitate oral challenge tests in all age groups, including young children, while maximizing the top dose in an acceptable volume. METHODS: Recipes were developed and subsequently validated by a panel recruited by a matching sensory test. The best 30% of candidates were selected to participate in sensory testing using the paired comparison test. RESULTS: For young children, three recipes with cow's milk and one recipe with peanut could be validated which may be utilized in DBPCFCs. For children older than 4 years and adults, one recipe with egg, two with peanut, one with hazelnut, and one with cashew nut were validated for use in DBPCFCs. CONCLUSIONS: All recipes contained larger amounts of allergenic foods than previously validated. These recipes increase the range of validated recipes for use in DBPCFCs in adults and children.

Identification of low allergenic apple cultivars using skin prick tests and oral food challenges.

BACKGROUND: As oral allergy syndrome (OAS) symptoms to apple are frequent, we aimed to identify low allergenic apple cultivars and to validate the prick-to-prick skin prick test (SPT) as a suitable screening method. METHODS: Sixty-eight apple cultivars were tested by SPTs in 33 Dutch adults with OAS, before and during the birch pollen season in 2006 and 2007, respectively. Three cultivars yielding the largest number of negative SPTs (Elise, Santana and Pink Lady®) and one reference cultivar (Golden Delicious) were subsequently tested by single-blind oral food challenges (SBFC) just after picking in fall 2007 (fresh) and in spring 2008 (stored), outside the birch pollen season and preceded by SPTs. In spring, Santana was replaced by Modi®. RESULTS: In fresh apples, OAS symptoms of Elise, as measured by cumulative scores on a Visual Analogue Scale VASt, were significantly lower than those of Santana, Pink Lady and Golden Delicious (P = 0.021; 0.040 and 0.005, respectively). VASt scores of Santana were significantly lower than those of Golden Delicious (P = 0.049). In stored apples, VASt scores of Elise were significantly lower than that of Golden Delicious (P = 0.038). VASt scores of fresh apples did not differ significantly from stored apples, except in Golden Delicious (spring < fall: P = 0.021). The SPTs did not predict the severity of OAS. CONCLUSION: SPTs are not useful to assess the allergenicity of apple cultivars. By using SBFC, Elise and Santana were identified as low allergenic apple cultivars in patient with OAS. Our data on the effect of storage are inconclusive.

Health-related quality of life of food allergic patients: comparison with the general population and other diseases.

BACKGROUND: To date no studies have compared generic health-related quality of life (HRQL) of food allergic patients from childhood to adulthood with that of the general population or patients with other chronic diseases. The aim of this study was to compare generic HRQL of food allergic patients with the general population and other diseases. METHODS: Generic HRQL questionnaires (CHQ-CF87 and RAND-36) were completed by 79 children, 74 adolescents and 72 adults with food allergy. The generic HRQL scores were compared with scores from published studies on the general population and patients with asthma, irritable bowel syndrome (IBS), diabetes mellitus (DM) and rheumatoid arthritis (RA). RESULTS: Food allergic children and adolescents reported fewer limitations in school work due to behavioural problems (P < or = 0.013), but food allergic adolescents and adults reported more pain (P = 0.020), poorer overall health (P < 0.001), more limitations in social activities (P < 0.001) and less vitality (P = 0.002) than individuals from the general population. Food allergic patients reported poorer generic HRQL than patients with DM, but better generic HRQL than patients with RA, asthma and IBS. CONCLUSION: HRQL is impaired in food allergic adolescents and adults, compared to the general population, and it is intermediate in magnitude between DM and RA, asthma and IBS. Children show the least impact on generic HRQL from food allergy.

Health-related quality of life of food allergic patients measured with generic and disease-specific questionnaires.

BACKGROUND: Health-related quality of life (HRQL) has never been measured with both generic and disease-specific questionnaires in the same group of food allergic patients. The aim of this study was to compare HRQL of food allergic patients as measured with generic and disease-specific questionnaires. METHODS: Generic questionnaires (CHQ-CF87 and RAND-36) and disease-specific HRQL questionnaires (FAQLQ-CF, -TF and -AF) were completed by 79 children, 74 adolescents and 72 adults with food allergy. Floor and ceiling effects, percentage of agreement and multivariate stepwise regression analysis were used to compare the generic and disease-specific measurements. RESULTS: The Food Allergy Quality of Life Questionnaires (FAQLQs) showed minimal floor or ceiling effects. The CHQ-CF87 and RAND-36 showed minimal floor effects, but remarkable ceiling effects (> 73%) were found for the scales role functioning-emotional (RE), role functioning-behaviour (RB), role functioning-physical (RP) in children and adolescents and the scale RE (> 79%) in adults. Additionally, we found low percentages of agreement between the generic and disease-specific questionnaires to identify the same food allergic patients with the best or worst HRQL. Only patients with the best disease-specific HRQL also tended to have the best generic HRQL. Finally, the explained variance in HRQL by patient characteristics was higher in the disease-specific questionnaires (30.7-62.8%) than in the generic scales (6.7-31.7%). CONCLUSION: Disease-specific HRQL questionnaires may be more suitable to measure clinically important impairments in HRQL or HRQL differences over time in food allergic patients. However, generic HRQL questionnaires are indispensable for the comparison between different diseases and are thus complementary.

Development, validity and reliability of the food allergy independent measure (FAIM).

BACKGROUND: The Food Allergy Quality of Life Questionnaire-Child Form, -Teenager Form and -Adult Form (FAQLQ-CF, -TF and -AF) have recently been developed. To measure construct validity in the FAQLQs, a suitable independent measure was needed with which FAQLQ scores could be correlated. However, in food allergy, no appropriate independent measure existed, which could be used for this purpose. AIMS OF THE STUDY: The aim of this study was to describe the development of a Food Allergy Independent Measure Child-Form, -Teenager Form and -Adult Form (FAIM-CF, -TF and -AF) and to assess their validity and reliability. METHODS: The FAIMs were developed using previously established methodology to capture the patients' expectation of outcome (EO). Face validity was determined by expert opinion. FAIM questions showing no correlation to any potential items in the FAQLQs were considered irrelevant and eliminated. To measure test-retest reliability, one-hundred and one patients were included and completed the FAIM twice with a 10-14 day interval. The intraclass correlation coefficient (ICC), Lin's concordance correlation coefficient (CCC) and Bland-Altman plots were used to assess test-retest reliability. RESULTS: Six FAIM questions were developed and considered relevant for the FAIM-CF and -AF, and five questions were relevant for the FAIM-TF. The FAIMs showed good reliability with ICCs and CCCs above 0.70 and with mean differences all close to zero. CONCLUSIONS: Food allergy independent measures were developed for children, adolescents and adults and were shown to be valid, relevant and reliable. This supports the suitability of the FAIMs for evaluating construct validity.

Development and validation of a self-administered Food Allergy Quality of Life Questionnaire for children.

BACKGROUND: Having a food allergy may affect health-related quality of life (HRQL). Currently, no validated, self-administered, disease-specific HRQL questionnaire exists for children with food allergy. OBJECTIVE: The aim of this study was to develop and validate the Food Allergy Quality of Life Questionnaire--Child Form (FAQLQ-CF) in the Dutch language. METHODS: Interviews with food-allergic children (n=13, 8-12 years) generated 139 HRQL items. The most important items were identified by 51 food-allergic children using the clinical impact method. This resulted in the FAQLQ-CF containing 24 items (total score range 1 'not troubled' to 7 'extremely troubled'). The FAQLQ-CF, the Food Allergy Independent Measure (FAIM) and a generic HRQL questionnaire (CHQ-CF87) were sent to 115 food-allergic children for cross-sectional validation of the FAQLQ-CF. RESULTS: Construct validity was demonstrated by the correlation between the FAQLQ-CF and the FAIM (rho=0.60, P<0.001). The FAQLQ-CF had an excellent internal consistency (Cronbach's alpha=0.94) and discriminated between children who differed in number of food allergies (>2 food allergies vs. < or =2 food allergies; total FAQLQ-CF score, 4.3 vs. 3.6; P=0.036), but did not discriminate between reported anaphylaxis or not. The total FAQLQ-CF score correlated with 8 of the 11 CHQ-CF87 sub-scales which demonstrated convergent/discriminant validity. CONCLUSION: The FAQLQ-CF is the first self-administered disease-specific HRQL questionnaire for food-allergic children. This questionnaire has a strong internal consistency and cross-sectional validity. It discriminates between children who differ in number of food allergies, and it was short and easy to use in the population studied. Therefore, the FAQLQ-CF may be a useful tool in clinical research.

Development and validation of the Food Allergy Quality of Life Questionnaire - Adult Form.

BACKGROUND: Health-related quality of life (HRQL) may be affected by food allergy. Presently, no disease-specific HRQL questionnaire exists for food allergic adults. Therefore, we developed and validated the Food Allergy Quality of Life Questionnaire - Adult Form (FAQLQ-AF) in the Dutch language. METHODS: Twenty-two food allergic patients (> or =18 years) were interviewed and generated 180 HRQL items. The most important items were identified by 54 food allergic patients using the clinical impact method resulting in the FAQLQ-AF containing 29 items (score range 1 'not troubled' to 7 'extremely troubled'). The FAQLQ-AF, the Food Allergy Independent Measure (FAIM) and a generic HRQL questionnaire (RAND-36) were sent to 100 other food allergic adults for cross-sectional validation of the FAQLQ-AF. RESULTS: Cross-sectional validity was assessed by the correlation between FAQLQ-AF and FAIM (rho = 0.76, P < 0.001). The FAQLQ-AF had excellent internal consistency (Cronbach's alpha = 0.97). The FAQLQ-AF discriminated between patients who differ in severity of symptoms (anaphylaxis vs no anaphylaxis, total FAQLQ-AF score 4.9 vs 4.1; P = 0.041) and number of food allergies (>3 food allergies vs< or =3 food allergies, total FAQLQ-AF score 5.2 vs 4.2; P = 0.008). The total FAQLQ-AF score was correlated with one RAND-36 scale (convergent/discriminant validity). CONCLUSIONS: The FAQLQ-AF is the first disease-specific HRQL questionnaire for food allergic adults and reflects the most important issues that food allergic patients have to face. The questionnaire is valid, reliable and discriminates between patients with different disease characteristics. The FAQLQ-AF is short and easy to use and may therefore be a useful tool in clinical research.