Common Food Allergens In Children Research Articles

A cross-sectional study of the prevalence of food allergies among children younger than ages 14 years in a Beijing urban region.

Background: The prevalence of food allergies has increased over the past several decades, but little is known about this issue in Beijing. Objective: The objectives of this study were to assess the prevalence of food allergies in the Beijing urban area and to summarize the clinical features and common food allergens in children <14 years of age. Methods: We conducted a cross-sectional study of children ages 0-14 years who were recruited from 10 kindergartens and 20 primary and middle schools in two communities in the central region (Xicheng district). After the administration of a screening questionnaire, those who reported symptoms of food allergies were interviewed for further diagnoses. All data were analyzed by using χ² tests. Results: Of the 13,073 enrolled children, 423 children (3.2%) were deemed by physicians to probably have food allergies. The boys exhibited a significantly higher prevalence than did the girls (3.6 versus 2.9%, respectively, p < 0.05). Among the children with probable food allergies, 58.9% reported skin symptoms, which were the most frequently occurring symptom type. Preschool age was the most common onset age for food allergies, with a rate (41.8%) that was higher than those for infants (27.1%) and school-age children (31.1%) (p < 0.01). Fruit was the most commonly reported food allergen (46.8%). Food allergies due to milk and eggs mainly occurred during infancy, and fruit allergies occurred in preschool- and school-age children. The seafood allergy prevalences were nearly the same across the three age groups. Conclusion: The total prevalence of probable food allergies in children <14 years of age in the Beijing urban area was 3.2%, and the prevalences were different between genders and among ages and foods. Skin symptoms were the most common manifestation. Fruit and seafood were the most common allergens.

What Do We Know Now about IgE-Mediated Wheat Allergy in Children?

IgE-mediated wheat allergy is a gluten-related disorder. Wheat is one of the five most common food allergens in children. However, the natural history of IgE-mediated wheat allergy has seldom been described in the research literature. This study presents the current state of knowledge about the IgE-mediated wheat allergy in children.

The Most Common Food Allergens in Patients with Allergy Symptoms referred to Mofid Children’s Hospital (2013-15)

Introduction: Food allergy (FA) is heterogeneous disease, affecting multiple organs like skin, respiratory or gastrointestinal tracts, which have different forms from a local allergy to a systematic anaphylaxis. The prevalence of FA is about 4% among children in the world and the prevalence is increasing recently. Th2 and IgE-mediated reactions play an important role in this disease. In this study we determined the most common food allergens in children referred to Mofid Children's Hospital. Materials and methods: This cross-sectional study was performed on 396 patients with skin, respiratory and gastrointestinal allergies, which were referred to Mofid Children's Hospital, 2013-15. Allergen specific IgE was measured via an immunoblotting method using AlleisaScreen® system kit and their data were collected. Results: Of 396 patients 246 (62.1%) were male and 150 (37.9%) were female. The range of patient’s age was between1-12 and the mean± SD were 4.72±2.91 years. The most common allergens were milk, wheat flour, egg white, casein and cheese mix, respectively. Conclusion: This study showed that the order of common food allergens in this study was different from other reports; this might be due to the different food habits and /or ethnic diversities.

Clinical analysis of food serum specific IgE in children with allergic rhinitis in Tianjin

Objective: To define the common food allergens in children with allergic rhinitis in Tianjin with detection of serum specific immunoglobulin E(IgE) against foods and inhalation.Method:Mediwiss(Screen Allergy) was used to determine serum specific IgE. The relationships between food allergy and gender, age, season were also analyzed.Result:Most common food allergens in children with AR in Tianjin are milk(17.28%), followed by egg white(13.79%), crab(9.56%) and cashew nuts(8.64%). Children in food-related allergy group were significantly less than that in the inhalation-related allergy group, the difference was statistically significant（P <0.05）. Among food-related allergy group, one hundred and ninty four cases are both sensitive to food allergens and inhalation allergens, and the other 34 cases are only sensitive to food allergens. There were significant differences about the positive rate of allergy between different age groups(P <0.01).There was no significant difference in the total food allergens sensitivity rate between different gender and seasonal groups（P >0.05）. The cashew and beef allergen sensitivity rates are different between male and female. The sensitivity rates of amaranth, egg, white milk, and crab are different among different age groups. The difference was statistically significant（P <0.05）.Conclusion: Milk, egg, crab, cashew nuts are the most common food allergens in children with AR in Tianjin area. Only food-related allergy is rare, food allergies are usually accompanied by inhalation-related allergy. Cashew allergen sensitivity rate was higher in male than female. Milk allergen sensitivity rate was higher in female than male. Sensitivity rate of amaranth allergen increased significantly, while that of egg milk and crab allergen decreased significantly with age.

Top 10 food allergy myths.

A positive SPT (i.e. wheal ≥3 mm) or ssIgE (>0.35 KU/L) indicates that allergen specific IgE is being produced. This is known as being sensitised to the allergen. It does not prove that the patient is clinically reactive to the allergen or will have an IgE-mediated allergic reaction to that food. For some common food allergens including egg, cows milk and peanut, the size of the SPT and/or level of ssIgE correlates with an increased likelihood of a clinical IgE-mediated allergic reaction to that food. Positive predictive values (PPVs) for common allergens can assist in ruling a food allergy in, and in decreasing the need for a confirmatory oral food challenge (OFC), where the level of IgE is above the 95% PPV for that food. PPVs have been more difficult to establish for wheat, soy, tree nuts and fish. Moreover, many children’s SPT size or ssIgE levels fall between the lower limit of positive and these high cut-off points. Approximately 30–50% of children with sensitisation to food allergens do not react with IgE-mediated symptoms (urticaria, angiooedema, stridor, vomiting, bronchospasm, cardiovascular compromise, etc.) on exposure to the allergen and are clinically tolerant to the food in question. A positive SPT or ssIgE should be interpreted in the context of the patient’s history, particularly previous exposures to an allergen. Because of the high false positive rate of these tests, ‘fishing expeditions’ where large panels of testing are performed to screen for potential food allergies are not recommended. Targeted screening for few (three or less) very common food allergens in children at very high risk may be indicated in some circumstances. An individual sensitised to a food on SPT or ssIgE who has a history of regular ingestion of that food without IgE-mediated allergic symptoms is not allergic to that food via a IgE-mediated mechanism and should not be advised to exclude it from their diet on the basis of the positive test. Allergen exclusion in these circumstances for periods of greater than 3 months under can result in severe allergic reactions on re-exposure to the previously tolerated foods. In rare circumstances where a food needs to be removed from the diet, where sensitisation is present, and the child is clinically tolerant, extreme caution should be taken in reintroduction of that food.

The natural history of IgE mediated wheat allergy in children with dominant gastrointestinal symptoms

BackgroundWheat is one of the most common food allergens in children. The purpose of this study is to define the natural course of wheat allergy in children with dominant gastrointestinal symptoms and identify factors that help predict development of tolerance.MethodsThe prospective analysis covered 50 children with positive food challenge results (DBPCFC) and positive wheat IgE test result. Resolution of wheat allergy was determined on the basis of food challenge results (open challenge). The impact of each of the studied factors on the age when tolerance developed was assessed by means of the Cox proportional hazard regression model.ResultsThe median age of tolerance development was 69.5 months (37-192 mo.). The rates of resolution were 20% by the age of 4 years, 52% by the age of 8 years, and 66% by 12 years, and 76% by 18 years. The median age of the tolerance development in children with peak wheat IgE level below10 kU/L was 41.4 months, with peak wheat IgE from 10 to 19.9 kU/L was 44.5 months, with peak IgE from 20 to 49.9 kU/L – 84,9 months and with peak IgE ≥ 50 kU/L – 190.5 months. The median of the age when the highest levels of IgE for wheat were reached was 33 months (2-52 mo.) in children with resolved wheat allergy and 67 months (36-178 mo.) in children with persistent allergy (p = .001).Conclusions1. The majority of children with wheat allergy can tolerate wheat by adolescence. 2. The age when tolerance to wheat developed depended on the level and the age of reaching the highest levels of specific IgE for wheat. The higher the values of the above parameters, the older a child was when they developed tolerance to wheat.

Food-specific serum immunoglobulin E measurements in children presenting with food allergy

BackgroundIn children with food allergy, multiple food-specific serum IgE levels to common food allergens are frequently measured. ObjectiveTo compare food-specific serum IgE measurements among common food allergens in children with food allergy to determine the characteristics of the measurements, their ability to discriminate between foods associated and not associated with a presenting clinical reaction, and their change over time. MethodsA retrospective analysis was conducted of food-specific serum IgE to cow's milk, egg white and yolk, peanuts, almond, and soy, for up to 3 subsequent measurements, in 291 children with food allergy. A food-specific serum IgE level lower than 0.35 kU/L was considered a negative measurement. The correlation of IgE measurements with presenting symptoms was conducted for each food in 172 children. ResultsOf 1,312 food-specific serum IgE measurements, 69.8% were positive. The median (interquartile range) IgE level for foods associated with the presenting complaint was 7.3 kU/L (2.7–31) and that for foods not associated with a clinical complaint was 2.2 kU/L (0.38–13). The difference was statistically significant (P = .01) only for cow's milk. Specific IgE levels were highest for peanuts, followed by cow's milk, eggs, soy, and almonds, and trended upward over time. ConclusionIn children presenting with clinical symptoms of a reaction to a food allergen, measurements of food-specific serum IgE to other common food allergens are commonly positive. An increase in food-specific serum IgE occurs over time.

Sensitization patterns of cow’s milk and major components in young children with atopic dermatitis

BackgroundCow's milk (CM) is one of the most common food allergens in children with atopic dermatitis (AD), and the component-specific immunoglobulin E (component-IgE) measurement has recently become available.ObjectiveThis study aimed to investigate the sensitization patterns to CM and 3 major components and their clinical values in young Korean children with AD.MethodsCow's milk-specific IgE (CM-IgE), α-lactalbumin-specific IgE (ALA-IgE), β-lactoglobulin-specific IgE (BLG-IgE), and casein-specific IgE (Cas-IgE) levels from the sera of patients with AD were measured using the UniCAP™ system (Thermo Fisher Scientific, Sweden) and collected from January 2004 to December 2010. Patients ≥ 4 years of age were excluded from the analysis.ResultsA total of 950 patients diagnosed with AD were ultimately enrolled in the study. Among them, 471 (49.6%) patients were sensitized to CM (CM-IgE[+], > 0.35 kU/L). Sensitization to casein (n = 349, 74.1%) was most common, followed by ALA (n = 283, 60.1%), and BLG (n = 245, 52.5%). Meanwhile, 95 patients had at least 2 follow-up tests. Eighty (84.2%) of these patients tested positive to CM, and the casein sensitization rate was the highest (n = 65, 81.3%). In addition, 479 (50.4%) patients were not sensitized to CM (CM-IgE[-], ≤ 0.35 kU/L) but 35 (7.3%) patients were sensitized to at least one component. Among them, a telephone survey was accessible in 21 cases. A total of 8 (38.1%) patients still suffered from adverse reactions after consuming milk and/or dairy foods.ConclusionCasein was the most commonly and persistently sensitized component in CM-IgE(+) children with AD. Measuring CM component IgE antibodies, especially Cas-IgE, is helpful for evaluating problematic allergens in young children with AD.

Specific IgE to common food allergens in children with atopic dermatitis.

Atopic dermatitis is a major public health problem, often starting in early childhood and sometimes followed by other allergic diseases. Although hypersensitivity to foods is assumed to play an essential role in the development of atopic dermatitis in some patients, little is known about common food allergens in Iranian children with atopic dermatitis. This study was designed to identify probable food allergens in Iranian children with atopic dermatitis and find the relationship between food sensitization and the severity of atopic dermatitis. This study included 90 children aged 2-48 months with atopic dermatitis. Skin prick tests for cow's milk, hen's egg, almond, potato and soybean were done. Serum specific IgE to 20 food allergens was also screened. Among children with atopic dermatitis, the frequency of food sensitization was 40% by skin prick test and 51% by food-specific IgE. Children with atopic dermatitis were most commonly sensitized to cow's milk (31%), hen's egg (17.7%), tree nuts (17.7%), wheat (12.2%), potato (11.1%), tomato (8.8%) and peanut (8.8%). In 42 children with moderate to severe eczema, sensitivity to food allergens was 78.5% by skin prick test and 88% by serum specific IgE evaluation. Our results showed that cow's milk, hen's egg and tree nuts were the most common food allergens in Iranian children with atopic dermatitis. Sensitization to foods was much higher in patients with moderate to severe atopic dermatitis. Determining specific IgE in children with atopic dermatitis can be helpful in managing these patients.

Natural Course of Cow's Milk Allergy in Children with Atopic Dermatitis

Cow's milk is one of the most common food allergens in children with atopic dermatitis (AD). This study was conducted to describe the natural course of cow's milk allergy in children with AD, and to identify factors predictive of outcome. To accomplish this, we reviewed the medical records of 115 children who were diagnosed with AD and cow's milk allergy before 24 months of age to evaluate their clinical characteristics and prognostic factors. During a follow-up period of 24 to114 months, the median age for tolerance to cow's milk was found to be 67 months. Multivariate analysis using the Cox proportional hazard model revealed that the peak cow's milk-specific IgE level within 24 months after birth was the most important factor for prediction of the outcome of cow's milk allergy. In conclusion, half of the children younger than 24 months of age with AD and cow's milk allergy could tolerate cow's milk at 67 months of age. The peak cow's milk-specific IgE level within the first 24 months of birth is useful to predict the prognosis of cow's milk allergy in children with AD.

Effect of Six-Food Elimination Diet on Clinical and Histologic Outcomes in Eosinophilic Esophagitis

In children, eosinophilic esophagitis (EE) is predominantly, but not exclusively, a food-hypersensitivity disorder. A crystalline amino acid-based elemental diet (ELED) formula currently remains the most effective nutritional treatment in inducing clinical and histologic remission. However, compliance with an exclusive, poor-tasting liquid formulation is difficult. This retrospective observational study assessed the short-term clinical and histologic responses of 2 cohorts of children with EE evaluated during 2 different time periods: one was treated with the standard 6-food elimination diet (SFED) and the other was treated with ELED. Of the 60 children who met the inclusion criteria and were compliant with the dietary protocol, 35 were treated with a diet excluding cow-milk protein, soy, wheat, egg, peanut, and seafood while allowing all other table foods and 25 were treated exclusively with ELED. Repeat esophageal biopsy specimens were obtained at least 6 weeks later. Twenty-six of 35 (74%) in the SFED group and 22 of 25 (88%) in the ELED group achieved significant improvement of esophageal inflammation (</=10 eosinophils/high-power field). The pretreatment and posttreatment peak eosinophil counts for the SFED were 80.2 +/- 44.0 and 13.6 +/- 23.8 (P < .0001) and 58.8 +/- 31.9 and 3.7 +/- 6.5 (P < .001) for the ELED group, respectively. SFED treatment was associated with clinical and histologic improvement in EE in an observational study. It offers advantages of better acceptance, cost, and compliance than ELED and should be considered as an option in the initial management of children with EE.

The Role of Cow Milk Allergy in Increasing the Severity of Atopic Dermatitis

Previous studies have shown that up to 33% of children with atopic dermatitis have experienced food hypersensitivity and among different kinds of food allergens Cow Milk (CM) has almost always been one of the most common food allergens in children. The aim of this study is to evaluate the cow milk allergy (CMA) as an increasing factor of severity of atopic dermatitis. One hundred and nineteen children (between 1.5 months and 12 years of age) with atopic dermatitis in the sense of Hanifin and Rajka's criteria entered this study and the severity of atopic dermatitis was identified via the SCORAD index. In order to make the diagnosis of cow milk allergy, a careful history, and a familial history of allergy was taken and the results of skin prick test (SPT) with CM and 4 other food allergen extracts, Radioallergosorbent test (RAST) with CM allergens and a food challenge test with cow milk (fresh or dried) were used. Also a total serum IgE determination and an eosinophil count (with a stool exam) were accomplished. The clinical manifestations of atopic dermatitis in patients was started from their first day of life up to 10 years of age. The family history in 83% of the patients was positive. Positive skin prick test and RAST with CM allergens were positive in 37.9% and 29.3% of cases respectively and the response to challenge test with cow milk was positive in 35 out of 40 patients and in total 44.5% had CMA according to a positive history of cow milk allergy and a positive outcome of the IgE tests (SPT and/or RAST) or a positive challenge test with CM allergens. The results showed that the most common food allergens in patients with atopic dermatitis are certainly cow milk allergens (44.5%) whereas other food allergens are tomato (29.41%), egg (28.57%), nuts (9.24%) and wheat (3.36%) according to the skin prick test. The mean total serum IgE was 307.11 ± 6.56 IU/ml (range = 6–5000) in children with CMA and 81.04 ± 5.97 IU/ml (range = 1–5000) in children without CMA while the mean eosinophil count was 569.52 ± 3.02 count/ml (range = 67–8500) and 314.22 ± 2.94 count/ml (range = 5–5000) respectively. The mean severity of atopic dermatitis according to the SCORAD index was 60.76 in children with CMA and 44.29 in children without CMA. The severity of atopic dermatitis in patients with CMA was significantly higher than patients without CMA (p < 0.0001). Also the mean total serum IgE and mean eosionophil counts in children with CMA were significantly higher than in children without CMA (P < 0.01 and p < 0.0001, respectively). It shows the important role of CM allergen proteins in the induction and in increasing the severity of AD in children.

Clinical reactivity to beef in children allergic to cow's milk

Background: Cow's milk is one of the most common food allergens in children. Limited information is available on the prevalence of reactivity to a related food source, beef. The purposes of this study were to examine the prevalence of symptomatic sensitivity to beef in a selected pediatric population and to determine the frequency of concomitant reactivity to cow's milk and beef. Methods: Children referred for assessment of atopic dermatitis and possible food hypersensitivity were evaluated for symptomatic reactivity to beef by double-blind placebo-controlled food challenges (DBPCFCs) and subsequent open feedings of beef. Sodium dodecyl-sulfate–polyacrylamide gel electrophoresis (SDS-PAGE), immunoblot, and immunodot blot analyses were performed with patients' sera on preparations of beef extracts subjected to different cooking conditions: raw (no heating), medium, and well-cooked. Results: Eleven of 335 children referred for evaluation of atopic dermatitis and possible food hypersensitivity were found to have symptomatic sensitivity to beef; eight were also sensitive to milk, as demonstrated in previous DBPCFCs. Eight patients reacted to beef during DBPCFC, and three tolerated beef in a DBPCFC and well-cooked beef in an open challenge but reacted to ingestion of less well-cooked beef. SDS-PAGE of raw beef revealed at least 24 protein fractions. Several protein bands in raw beef appeared to denature with heating. Bovine serum albumin and bovine gamma globulin were heat-labile in the beef extract, but six protein fractions persisted even after heating the beef extract for 2 hours at 85° C. IgE from patients reacting to rare and well-cooked beef bound up to six of these heat-resistant fractions, but IgE from patients reacting only to rare beef failed to bind any of these fractions with one exception. In addition, patients reacting to rare and well-cooked beef had specific IgE to a 17.8 kd fraction, which was only weakly recognized by one patient reacting only to rare beef. Conclusions: Specific IgE antibodies to heat-labile beef proteins might explain why some patients can tolerate well-cooked beef but not medium-rare and rare beef. Patients reacting only to rare beef may not need to maintain a complete beef elimination diet. (J Allergy Clin Immunol 1997; 99:293-300.)