Dietary Avoidance Research Articles

Parent‐reported food allergy requiring an avoidance diet in children starting elementary school

To evaluate the prevalence of parent-reported food allergies requiring avoidance diet at early school age. The school health nurses interviewed, by using a structured questionnaire on the required diet at school, the parents of all the 1542 children starting elementary school in a Finnish town with 210,000 inhabitants. An allergy to basic foods was found in 41 (2.7%) children: 1.5% to milk, 1.1% to eggs and 1.0% to grains. An allergy to nuts was present in 3.1% and to fruits and vegetables in 5.8%, both with known cross-sensitization to pollens. In all, 9.2% of the children reported some allergy. Milk, egg and grain allergies were associated with soy, nut and spice allergies. Over 2% of the 1542 Finnish first-graders reported allergies to basic foods (milk, eggs or grains) requiring special avoidance diets at school. The figure suggests that avoidance diets started in the first years of life still unnecessarily continued.

Skin prick testing and peanut-specific IgE can predict peanut challenge outcomes in preschoolchildren with peanut sensitization

The rise in peanut allergy is a source of considerable burden in the community. A growing number of preschoolchildren have been identified as peanut sensitized in the course of investigation of other allergic conditions. Although many have never knowingly ingested peanuts and their clinical reactivity is not known, it has been common practice to place these children on avoidance diets for many years. To determine the utility of skin prick tests (SPT) and fluorescent-enzyme immunoassays (FEIA) for identifying either peanut allergy or tolerance in preschoolchildren with peanut sensitization. Forty-nine preschoolchildren (<5 years of age) with peanut sensitization (SPT ≥ 2 mm or peanut-specific IgE ≥ 0.35 kU/L) but unknown clinical reactivity had graded open peanut challenges reaching a total of 11 g. A positive challenge was defined as an objective IgE-mediated reaction during challenge or the 2-h observation. Forty-nine percent (24/49) of children had positive challenges. An SPT of >7 mm on the day of challenge predicted a positive challenge with a sensitivity of 83% and a negative predictive value (NPV) of 84%. An FEIA of >2.0 kU/L showed a sensitivity of 79% and an NPV of 80%. Predicting challenge outcome from a combination of SPT and FEIA (SPT >7 and/or FEIA >2 is positive) increased sensitivity to 96% and NPV to 95%. At least half of preschoolchildren with peanut sensitization and no antecedent history of peanut ingestion can tolerate peanuts. A SPT<7 mm and FEIA<2 kU/L identify children most likely to tolerate peanut, with only a 5% likelihood of failing an oral challenge. This study assists clinicians considering challenges in very young peanut-sensitized children.

Allergic Reactions to Food Proteins

Four to eight percent of the population are estimated to be food-allergic. Most food allergies in adolescents and adults are acquired on the basis of cross-reaction to pollen allergens. Theses allergens are ubiquitous in the plant kingdom. Therefore pollen-allergic patients might acquire a multitude of different plant food allergies, and even react to novel foods to which they have never previously been exposed. A curative therapy for food allergy does not yet exist. Food-allergic patients have to rely on strict avoidance diets, The widespread use of industrially processed foods poses a general problem for food-allergic patients. Although the most frequent allergens must be declared openly in the list of ingredients, involuntary contamination with allergy-provoking compounds can occur. The precautionary labelling "may contain" is sometimes applied even if the chance of contamination is very low; on the other hand, foods not declared to contain possible traces of allergenic components may actually contain relevant amounts of allergenic proteins. Switzerland is the only country in Europe with legal regulations on contamination by allergenic food; however, the allowance of 1 g/kg is too high to protect a relevant proportion of food-allergic individuals.

Impact of Denture Usage Patterns on Dietary Quality and Food Avoidance Among Older Adults

This study categorizes older adults living in rural areas by denture status, assesses the frequency of wearing dentures during meals, and determines whether denture status or use is associated with dietary quality or the number of foods avoided. A multi-ethnic population-based sample of adults ≥60 years (N = 635) in the rural United States was interviewed. Survey included denture use, removing dentures before eating, and foods avoided due to oral health problems. Dietary intakes were converted into Healthy Eating Index-2005 scores. Sixty percent wore removable dentures of some type; 55% never, 27% sometimes, and 18% always removed dentures when eating. More frequent removal was associated with lower dietary quality and more foods avoided. Those with severe tooth loss had the lowest dietary quality and avoided the most foods. Many rural older adults wear dentures. Learning how they adapt to denture use will offer insight into their nutritional self-management and help explain differences in dietary quality.

Chinese herbal medicine research in eczema treatment

Eczema is a chronic relapsing atopic dermatitis (AD) associated with pruritus, sleep disturbance and poor quality of life of the patient. Treatment of eczema includes use of emollient, topical and systemic antimicrobial agents, corticosteroid or immunomodulating agents. Many patients also seek alternative treatments such as dietary avoidance, supplementation or both. This article reviews the basic pathophysiology of eczema and clinical trials involving Chinese medicine in the treatment of eczema. Research reports on Chinese herbal medicine for eczema were retrieved from PubMed and the Cochrane Database for Systematic Reviews for this review. Only a few RCTs demonstrated the efficacy (or lack of efficacy) of Chinese medicinal herbs in treating atopic eczema. Further larger scale trials are warranted.

Guidelines for the Diagnosis and Management of Food Allergy in the United States: Summary of the NIAID-Sponsored Expert Panel Report

Guidelines for the Diagnosis and Management of Food Allergy in the United States: Summary of the NIAID-Sponsored Expert Panel Report

Systemic Contact Dermatitis in Children: How an Avoidance Diet Can Make a Difference

Systemic contact dermatitis is an under-recognized skin reaction that occurs secondary to systemic (oral, intravenous, intramuscular, inhaled, or subcutaneous) exposure to a hapten in a previously sensitized individual. Medicaments are the most common cause of SCD in the adult population, but other chemicals like nickel, cobalt, balsam of Peru, and formaldehyde have been implicated as well. Few reports in children exist to date. Dietary restriction has shown to be of some benefit in managing some adult patients. We present a case series of 8 pediatric patients diagnosed with SCD from the contact dermatology clinic, who showed marked improvement of their dermatitis after adequate dietary avoidance. We review common presentations of chemicals causing SCD in children and potential dietary modifications.

Comprehensive, Quantitative Mapping of T Cell Epitopes in Gluten in Celiac Disease

Celiac disease is a genetic condition that results in a debilitating immune reaction in the gut to antigens in grain. The antigenic peptides recognized by the T cells that cause this disease are incompletely defined. Our understanding of the epitopes of pathogenic CD4(+ )T cells is based primarily on responses shown by intestinal T-cells in vitro to hydrolysates or polypeptides of gluten, the causative antigen. A protease-resistant 33-amino acid peptide from wheat alpha-gliadin is the immunodominant antigen, but little is known about the spectrum of T cell epitopes in rye and barley or the hierarchy of immunodominance and consistency of recognition of T-cell epitopes in vivo. We induced polyclonal gluten-specific T cells in the peripheral blood of celiac patients by feeding them cereal and performed a comprehensive, unbiased analysis of responses to all celiac toxic prolamins, a class of plant storage protein. The peptides that stimulated T cells were the same among patients who ate the same cereal, but were different after wheat, barley and rye ingestion. Unexpectedly, a sequence from omega-gliadin (wheat) and C-hordein (barley) but not alpha-gliadin was immunodominant regardless of the grain consumed. Furthermore, T cells specific for just three peptides accounted for the majority of gluten-specific T cells, and their recognition of gluten peptides was highly redundant. Our findings show that pathogenic T cells in celiac disease show limited diversity, and therefore suggest that peptide-based therapeutics for this disease and potentially other strongly HLA-restricted immune diseases should be possible.

The effect of prenatal and postnatal dietary exposures on childhood development of atopic disease

Prenatal and early life dietary factors may influence asthma and allergic disease development. We review recent studies and consensus statements regarding the effects of prenatal/early life dietary exposures on atopic disease. The American Academy of Pediatrics consensus statement highlighted the inadequacy of evidence for pregnancy antigen avoidance diets or delay of infant complementary foods beyond 4-6 months. Recent studies raise the question of whether early food introduction may promote tolerance, though controlled trials are pending. A recent meta-analysis suggested that antioxidants may protect against the development of atopy. Furthermore, some of the conflicting results on the effects of vitamin E may be related to variability in the isoforms prevalent in local diet. Recent studies of vitamin D similarly suggest that it may be protective, though this remains controversial. Finally, prenatal methyl donor exposure promoted the development of allergy in an animal model. There are conflicting data on the effects of most prenatal and early childhood dietary exposures on childhood atopic disease. Longitudinal prenatal/birth cohort studies with prospective measurements and clinical supplementation trials of promising dietary factors will be needed to make reliable recommendations in this vulnerable population of pregnant women and their infants.

A survey on lifestyle and attitudes on fruit and vegetable consumption and participation in physical activity in a sample of secondary school and university students from Palermo, Western Sicily

Background: Fruit and vegetable (F&amp;V) consumption, and physical activity (PA), are thought to be some of the most important protective factors that can improve long-term health quality of life. Many epidemiological studies indicate, in fact, that F&amp;V consumption and PA are health-promoting and are correlated with the beneficial effects and positive outcomes such as preventing some chronic diseases. Evidence, however, indicates that large proportions of adolescents are not consuming the minimum servings of F&amp;V as recommended by experts and a high percentage of them have sedentary habits. Objective and method: The purpose of this research was to investigate knowledge and behaviors in a sample of secondary school, (250), and university students, (200), referred to F&amp;V consumption and PA. The instrument used for the survey was a questionnaire containing 19 items with multiple choice answers. Data were codified, descriptive analysis and ÷2 tests were computed through Openstat and Statistica software. Results: Only 24,2% of the individuals identified welfare as including healthy eating, and this attitude seemed to be associated with the students’ families educational level. Educational level was also positively associated with the awareness of the importance of a healthy diet for well-being and with PA practice. The percentage of students having knowledge of the expert recommendations on PA and eating guidelines about F&amp;V consumption was about one third of the entire population. Students who met the expert recommendation for daily servings of fruit and vegetables were 27,8%, while only 17,8% practiced regular PA. The principal source of information was university/school, (48,0% and 57,0%). Conclusions: Healthy dietary and PA habits are far from the optimal in our sample of students. Because of the importance for the prevention of many diseases and long term health, there is a need for interventions that target the youth and promote correct dietary habits and avoidance of physical inactivity. In particular, F&amp;V intake and PA practice should be implemented by means of educational interventions in opportune settings, especially targeting schools, families and communities.

Religiosity and the preventive health behaviour of young adults

The role of religiosity in preventive health behaviour has received relatively little systematic research attention. Even so, extant literature suggests that religion may play complex and varied roles in enhancing people‗s health. However, the evidence has been both diverse and fragmentary One hundred and sixty unmarried undergraduates aged 18-29 years filled in a religiosity scale and a health behaviour questionnaire. The health behaviour questionnaire assessed medical and dental check-up, dietary avoidance, physical exercise, cigarette and alcohol behaviour, physical self-examination and sexual behaviour. The results indicated a positive relationship between the degree of religiousness and health enhancing behaviours, and negative relationships between religiosity and health compromising behaviours. The strongest relationships are between medical check-up, sexual abstinence and avoidance of alcoholic beverages. All of these relationships suggest that the deeper the degree of religiousness the higher the level of preventive health behaviour engaged in by the individual.Key words: Religiosity, preventive health, young adults, habits, and life-styles.

Bacterial Superantigen Elicits Food-Induced Allergic Sensitization through Epicutaneous Exposure

RATIONALE: We hypothesize that epicutaneous exposure can result in allergic sensitization to food. The increasing prevalence of food allergies even with dietary avoidance recommendations and the critical association between atopic dermatitis and food allergies support this. An understanding of the routes of exposure resulting in allergic sensitization is necessary for the development of preventative strategies.

The changing frequency of celiac disease diagnosed at the Stollery Children's Hospital.

Celiac disease (CD) is recognized as one of the most common and important autoimmune gastrointestinal disorders affecting children. There is evidence that a diagnosis of CD during childhood improves health outcomes. The increasing prevalence of CD is due to increased awareness of the wide range of extraintestinal symptoms associated with CD. To determine whether there has been a temporal increase in the diagnosis of CD associated with an increased diagnosis of children without typical gastrointestinal symptoms at the Stollery Children's Hospital (Edmonton, Alberta). Patients with biopsy-proven CD diagnosed at the Stollery Children's Hospital from 1998 to 2007, were identified by retrospective chart review. Baseline and follow-up data, including demographics, symptoms, risk factors, anthropometrics and laboratory investigations, were collected. An increase in the frequency of diagnosis of CD was noted during the study period, particularly from January 2003 onward. Before January 2003, nine children were diagnosed with CD - all with typical symptoms. Between January 2003 and January 2007, inclusive, 149 children were diagnosed with CD, of whom 46% had absent or atypical symptoms. At follow-up, 96% of patients reported improved symptoms, including 53% of individuals who reported being asymptomatic before diagnosis. In the last four years of the period studied, the number of children diagnosed with CD at Stollery Children's Hospital increased 11-fold. Screening children at risk for CD, and those with atypical presentations, contributed to the increased number of diagnoses. Identification of CD and establishment of lifelong, dietary gluten avoidance during childhood has important health benefits and should be encouraged.

Quantitative Risk Assessment Relating to Adventitious Presence of Allergens in Food: A Probabilistic Model Applied to Peanut in Chocolate

Peanut allergy is a public health concern, owing to the high prevalence in France and the severity of the reactions. Despite peanut-containing product avoidance diets, a risk may exist due to the adventitious presence of peanut allergens in a wide range of food products. Peanut is not mentioned in their ingredients list, but precautionary labeling is often present. A method of quantifying the risk of allergic reactions following the consumption of such products is developed, taking the example of peanut in chocolate tablets. The occurrence of adventitious peanut proteins in chocolate and the dose-response relationship are estimated with a Bayesian approach using available published data. The consumption pattern is described by the French individual consumption survey INCA2. Risk simulations are performed using second-order Monte Carlo simulations, which separately propagates variability and uncertainty of the model input variables. Peanut allergens occur in approximately 36% of the chocolates, leading to a mean exposure level of 0.2 mg of peanut proteins per eating occasion. The estimated risk of reaction averages 0.57% per eating occasion for peanut-allergic adults. The 95% values of the risk stand between 0 and 3.61%, which illustrates the risk variability. The uncertainty, represented by the 95% credible intervals, is concentrated around these risk estimates. Children have similar results. The conclusion is that adventitious peanut allergens induce a risk of reaction for a part of the French peanut-allergic population. The method developed can be generalized to assess the risk due to the consumption of every foodstuff potentially contaminated by allergens.

Effect of Maternal Egg Consumption on Breast Milk Ovalbumin Concentration

Palmer D, Gold M, Makridess M. Clin Exp Allergy. 2008;38(7):1186–1191PURPOSE OF THE STUDY. To assess human milk ovalbumin concentrations after daily maternal ingestion of 1 cooked egg for a 3-week period.STUDY POPULATION. There were 32 mothers of singleton, breastfed, egg-sensitive infants with moderate-to-severe eczema. Egg sensitivity was identified by a positive skin-prick test result. Eczema was evaluated by using a standardized scoring system.METHODS. Families had an initial home visit by an experienced dietitian, which involved collection of demographic and dietary information. All women and children were asked to follow an egg-free diet from day 1 through the duration of the trial. Adherence to the egg-free diet was assessed via detailed dietary intake records for both mothers and children on days 1 to 3, 10 to 12, and 21 to 23. Mothers were randomly allocated to receive identical-appearing egg-free muffins or muffins containing 1 (55 g) whole egg. Each mother was given a 3-week supply of frozen muffins corresponding to her randomization group and consumed 1 muffin per day on days 3 through 23. Atopic dermatitis assessments were performed for each child at the commencement and completion of the trial. The mothers completed the Infant's Dermatitis Quality of Life Index 3 times during the trial. On days 3, 12, and 23, the mothers manually expressed 5 mL of breast milk into sterile containers before and 2, 4, and 6 hours after eating the test muffin. Breast milk samples were stored in the home freezer and collected on day 24. The breast milk samples were queried for ovalbumin concentration by using a sandwich enzyme-linked immunosorbent assay method. Breast milk ovalbumin concentrations (nanograms per milliliter) were plotted against time, and the resulting curve was used to determine peak ovalbumin concentrations and total ovalbumin excretions (nanograms per milliliter per hour). Independent-sample t tests, Mann-Whitney U tests, and Pearson's χ2 tests were used to investigate differences between the diet groups.RESULTS. Women in the egg group had higher ovalbumin concentrations in breast milk than did the control group at all time points. Within each dietary group, the frequency of ovalbumin detection, peak ovalbumin concentration, and total ovalbumin excretion did not differ at days 3, 12, and 23. Ovalbumin was not detected in the breast milk of 25% of the women in the egg group. Infant eczema symptom scores were significantly reduced with time for both groups.CONCLUSIONS. Human milk ovalbumin is related to maternal dietary egg intake. Comparable detection of ovalbumin across time suggests that ovalbumin does not accumulate in human milk. One quarter of the women had no ovalbumin detected in their breast milk on any of the study days, which suggests that some women either do not excrete ovalbumin in their breast milk when challenged with 1 egg or have delayed excretion beyond 6 hours. Maternal dietary avoidance of well-cooked egg may not be necessary for all breastfed infants with egg sensitivity and eczema.REVIEWERS COMMENTS. For breastfed infants with food allergy, strict avoidance of the offending food proteins for both mother and child is frequently recommended. Total dietary avoidance of egg is difficult for patients to achieve. Additional study is needed to substantiate or to refute the preliminary observation that regular maternal ingestion of a small quantity of well-cooked egg did not markedly exacerbate eczema symptoms in egg-sensitive breastfed infants.

Early Consumption of Peanuts in Infancy Is Associated With a Low Prevalence of Peanut Allergy

Du Toit G, Katz Y, Sasieni P, et al. J Allergy Clin Immunol. 2008;122(5):984–991PURPOSE OF THE STUDY. To determine the prevalence of peanut allergy (PA) among Israeli and United Kingdom Jewish children and to evaluate the relationship of PA to peanut consumption by infants and mothers.STUDY POPULATION. The study included Jewish children between the ages of 4 and 19 years who attended targeted primary and high schools. Eligible Jewish schools in greater London, United Kingdom, and Israeli schools in the Mehoz Merkaz region of Tel Aviv were selected because they were thought to represent comparable residential environments. The mothers of Jewish infants 4 to 24 months of age in general practitioner clinics in the United Kingdom and Tipat Halav clinics in Israel were also surveyed about the timing of ingestion of peanut.METHODS. Two validated questionnaires were used. The Food Allergy Questionnaire was completed by high school pupils and by parents on behalf of primary school pupils; it asked about allergies to cow's milk, hen's egg, sesame, peanut, tree nuts, asthma, hay fever, and eczema and parental occupation. The Food Frequency Questionnaire, a validated consumption questionnaire given to mothers in the waiting room, made a detailed determination of peanut, sesame, and other solid-food consumption during the child's first year and by the mother during pregnancy and lactation. All children with a questionnaire-based diagnosis of PA were invited for allergy testing; PA was confirmed if skin-prick test results, specific immunoglobulin E (IgE) measurements, or both were greater than the 95% positive predictive values or if children had a positive oral peanut-challenge result.RESULTS. The Food Allergy Questionnaires were distributed to 10 786 children, and 81.8% were returned. Mothers returned 176 Food Frequency Questionnaires; none declined participation. The prevalence of PA in the United Kingdom was 1.85% and that in Israel was 0.17% (P < .001). After adjustment for atopy, the relative risk for PA in the United Kingdom was 5.8 (95% confidence interval: 2.87–11.8) for all children and 9.8 (95% confidence interval: 3.1–30.5) for primary school children. In terms of dietary assessments, the Kaplan-Meier plots for the age of introduction of solid foods were similar in the 2 countries; the introduction of egg, soybean, wheat, vegetables, fruits, and tree nuts was similar. However, with the introduction of peanut there was a significant difference between the 2 countries; by 9 months of age, 69% of Israelis were eating peanut, compared with only 10% of United Kingdom infants. The median monthly consumption of peanut in Israeli infants 8 to 14 months of age was 7.1 g of peanut protein and that in United Kingdom infants was 0 g (P < .001). Similar contents of major peanut allergens were demonstrated in products from the 2 countries, as well as similar levels of IgE binding between the products.CONCLUSIONS. The prevalence of PA is 10-fold higher in Jewish children in the United Kingdom, compared with that seen in Jewish children in Israel. The differences cannot be explained by differences in age, gender, ancestry, atopy, or socioeconomic class. The most obvious difference in the diet of infants in the 2 populations occurs in the introduction of peanut. Israeli infants are introduced to peanut during early weaning and continue to eat peanut more frequently and in higher amounts than United Kingdom infants, who avoid peanut. It has been proposed that different methods of preparing peanut could be responsible for the different rates of PA in different countries, but commonly consumed peanut-containing foods in both countries are derived from roasted peanut butter, and equivalent amounts of total protein, major peanut allergen, and IgE binding were demonstrated among these foods.REVIEWERS COMMENTS. This study demonstrated a strong inverse association between peanut consumption in infancy and the prevalence of PA in childhood. It is compelling that the early introduction of frequent and high doses of peanut protein in infants may lead to oral tolerance. Although there is inherent selection bias and recall bias with questionnaires in general, the authors of this study attempted to reduce both of these factors. Until recently, dietary avoidance of peanut during pregnancy, breastfeeding, and early childhood was recommended in the United States. This article prompts us to question our practices and recommendations in terms of introduction of peanut into our children's diet and how it may affect their propensity to develop PA. An ongoing study, Learning Early About Peanut Allergy (LEAP), which is being conducted by the authors of this article, should provide much-needed evidence for guidelines on the introduction of peanut into the diet of infants and children.

Identification of European Allergy Patterns to the Allergen Families PR-10, LTP, and Profilin from Rosaceae Fruits

High fruit intakes are associated with significant health benefits but fruit allergy sufferers may be discouraged from eating fruit due to the symptoms they experience. Knowledge about allergens involved in fruit allergy and the frequent cross-reactions to other allergens is essential to (a) design the best strategy for fruit allergy testing (b) prescribe optimal avoidance diets, and (c) design technological solutions for development of hypoallergenic fruits. The objective of this review was to investigate whether some characteristic disease entities could be identified in Europe for allergy to Rosaceae fruits. Five allergy patterns were found involving the allergen families PR-10, LTP, and profilin. In the Western Mediterranean area allergies to Rosaceae fruits are caused by monosensitization to LTP, monosensitization to profilin, or co-sensitization to both these allergens. On the contrary, monosensitization to PR-10 and, to a lesser degree, co-sensitization to profilin and PR-10 is dominant in Northern and Central Europe. LTP sensitization is present both in pollinosis and non-pollinosis patients and is associated with peach allergy in particular. The disease pattern for patients sensitized to profilin is characterized by several concomitant allergies including grass and other pollens, Rosaceae and non-Rosaceae fruits. Finally, PR-10 sensitization is primarily associated to concomitant birch pollen and apple allergy.

Utility of diagnostic tests in the follow‐up of egg‐allergic children

Better knowledge of the accuracy of a skin prick test (SPT) and specific IgE (sIgE) levels to egg allergens would help to identify persistent egg-allergic children, avoiding unnecessary risky challenges. This study was designed to assess the accuracy of a SPT and sIgE levels to egg allergens in order to determine persistent egg allergy in IgE-mediated allergic children after an egg-free diet. Children below 16 years were prospectively and consecutively recruited. Inclusion criteria were: allergy to egg proteins (children with a positive clinical case of IgE-mediated egg allergy and a positive SPT to egg allergens and/or positive sIgE levels), and strict egg avoidance diet followed for at least 6 months. Clinical histories were recorded and all patients underwent SPTs, sIgE levels to egg allergens and the gold standard -a double-blind placebo-controlled egg challenge (DBPCFG). DBPCFG was interpreted without knowledge of the results of the other tests and vice-versa. A SPT and sIgE levels' ROC curves analysis was performed to compare the diagnostic performance of the different tests. Finally, 157 children were included in the study. One hundred out of these 157 children (63.7%) had a positive oral challenge. Ninety-six were male (61%), and the median age was 2.5 years. One hundred and three (66.9%) had atopic dermatitis. A 7 mm egg white prick test had a positive likelihood ratio (+LR) of 6.7, and a level of 1.3 KU/L egg white-sIgE had a +LR of 5.1. A 7 mm egg white SPT had a positive predictive value of 92.3% (95% CI 85.1-99.5), and for a 9 mm egg white SPT this value was 95.6% (95% CI 87.3-100.0). For egg white-sIgE, 1.5 KU/L had a positive predictive value of 90.4% (95% CI 82.4-98.4) and for 25 KU/L it was 100.0% (95% CI 100.0-100.0). SPTs with ovotransferrin and lysozyme showed the lowest accuracy, followed by yolk and ovalbumin SPTs. This study is the first to evaluate both tests (SPT and sIgE levels) and all egg allergens to determine the persistence of egg allergy in IgE-mediated allergic children. Measuring the SPT and sIgE levels is useful to predict persistent allergy in these children, especially with the egg white complete extract. An oral challenge should not be performed in egg allergic paediatric patients with either an egg white prick test above 7 mm or a white egg-sIgE determination above 1.3 KU/L, because there is a 90% probability of remaining allergic.

Egg allergy in childhood: an update

Allergy to hen's egg is common in infancy and childhood. The management of egg allergy involves dietary avoidance of egg-containing foods, implementation of anaphylaxis precautions and ongoing monitoring for tolerance development. In this article, we review the recent literature regarding the immunology, clinical presentation, diagnosis, management and natural history of egg allergy. Retrospective studies suggest that most egg-allergic children will become tolerant over time. Regular ingestion of small quantities of cooked egg in baked products is often well tolerated and may hasten tolerance development. Influenza vaccination of egg-allergic patients remains controversial, and immunization of patients with previous significant reactions or anaphylaxis to egg is currently not recommended. In recent years, there has been increasing success in clinical trials of specific oral tolerance induction to egg, but concerns regarding the safety and long-term efficacy still preclude the use of oral immunotherapy in clinical practice. Egg allergy generally has a good prognosis. Despite recent advances in oral immunotherapy trials, the treatment of egg allergy currently relies on avoidance of egg-containing foods until tolerance has developed. It remains unclear whether the ongoing low-dose exposure to egg proteins in cooked foods improves the natural history of egg allergy.

Dietary advice, dietary adherence and the acquisition of tolerance in egg‐allergic children: a 5‐yr follow‐up

IgE-mediated egg allergy is a common childhood food allergy affecting about 1-2% of 2-yr-old children. Egg avoidance is the mainstay of treatment for egg allergy; however, it is unclear what type of dietary advice parents of children with egg allergy receive and to what extent this dietary advice is adhered to. This study aimed to assess: (i) the type and source of dietary advice parents receive in a tertiary hospital setting, (ii) how closely parents adhere to advice given, (iii) what patient characteristics influenced adherence to diet and (iv) whether strict adherence to dietary advice was an identifiable factor in whether children outgrew their egg allergy. In 2006, a questionnaire was sent to 261 parents of children seen in a tertiary paediatric allergy clinic in 2003 and diagnosed with egg allergy which included 84 children who had undergone an in-hospital open oral egg challenge during this time period (2003-2006). Questions included demographic data, details of egg allergy, dietary avoidance and attainment of unrestricted egg ingestion. Of 199 questionnaires confirmed received, 167 were returned (84%). The mean age of the cohort was 6.6 yr with an average of 5.5 yr of follow-up since the first reaction. Sixty-eight percent of subjects reported avoidance of all food containing egg all the time. Forty-seven percent of the children had been accidentally exposed to egg. The severity of the initial reaction did not appear to influence adherence to an advised diet. Of the 84 children who underwent in-hospital open egg challenges, 57 children were able to ingest egg without clinical reaction and were classified as having outgrown their egg allergy. These children did not differ from those who were challenge positive to egg in terms of either the dietary advice they received or the degree to which they had undertaken strict avoidance of egg. In addition, children who had outgrown their egg allergy did not differ from those who remained egg-allergic on in-hospital challenge in terms of either the frequency of accidental ingestion or the severity of initial reaction. Strict avoidance of egg and accidental ingestion of egg did not appear to influence the acquisition of tolerance.