Phenotypes of IgE-mediated food allergy in Turkish children

Data on food allergy-related comorbid diseases and the knowledge on factors associating specific food types with specific allergic outcomes are limited. The aim of this study was to determine the clinical spectrum of IgE-dependent food allergy and the specific food-related phenotypes in a group of children with IgE-mediated food allergy. Children diagnosed with IgE-mediated food allergy were included in a cross-sectional study. IgE-mediated food allergy was diagnosed in the presence of specific IgE or skin-prick test and a consistent and clear-cut history of food-related symptoms or positive open provocation test. Egg (57.8%), cow's milk (55.9%), hazelnut (21.9%), peanut (11.7%), walnut (7.6%), lentil (7.0%), wheat (5.7%), and beef (5.7%) were the most common food allergies in children with food allergy. The respiratory symptoms and pollen sensitization were more frequent in children with isolated tree nuts-peanut allergy compared with those with egg or milk allergy (p < 0.001); whereas atopic dermatitis was more frequent in children with isolated egg allergy compared with those with isolated cow's milk and tree nuts-peanut allergy (p < 0.001). Children with food allergy were 3.1 (p = 0.003) and 2.3 (p = 0.003) times more likely to have asthma in the presence of allergic rhinitis and tree nuts-peanut allergy, respectively. Interestingly, children with atopic dermatitis were 0.5 (p = 0.005) times less likely to have asthma. Asthma (odds ratio [OR], 2.3; p = 0.002) and having multiple food allergies (OR, 5.4; p < 0.001) were significant risk factors for anaphylaxis. The phenotypes of IgE-mediated food allergy are highly heterogeneous and some clinical phenotypes may be associated with the specific type of food and the number of food allergies.     

Food allergy and asthma morbidity in children

BACKGROUND: Coexisting food allergy and asthma is a significant problem in the pediatric population. Studies have looked at the association between food sensitization and asthma severity. It is unknown whether specific food allergies are associated with increased asthma morbidity. OBJECTIVE: We studied the independent effect that allergy to egg, milk, fish, and peanut has on the number of hospitalizations and courses of systemic steroids in children with asthma. METHODS: We performed a medical record review to evaluate the effect food allergy to egg, fish, peanut, and milk has on asthma morbidity. We reviewed the records of 201 children aged 3 months to 14 years with the diagnosis of asthma (ICD-9 codes 493.90, 493.91, and 493.92), of which 88 had coexistent food allergy. All children in the food allergy group had food-specific IgE concentrations greater than the 95% positive predictive value. We compared the rate of hospitalizations and use of systemic steroids between children with asthma and food allergies and those without coexisting food allergy using direct-entry, multiple regression analysis. Patients were adjusted for the severity of their asthma based on symptoms documented at their first visit to the allergist according to the National Asthma Education and Prevention Program guidelines and presence of environmental allergy, eczema, smoke exposure, and gastroesophageal reflux. RESULTS: Peanut and milk allergies were both associated with increased number of hospitalizations (P=0.009, 0.016), and milk allergy was associated with increased use of systemic steroids (P=0.001). CONCLUSION: Peanut and milk allergies were associated with increased hospitalization and steroid use and may serve as early markers for increased asthma morbidity.     

Allergen Component Testing for Food Allergy: Ready for Prime Time?

Food allergies can cause life-threatening reactions and greatly influence quality of life. Accurate diagnosis of food allergies is important to avoid serious allergic reactions and prevent unnecessary dietary restrictions, but can be difficult. Skin prick testing (SPT) and serum food-specific IgE (sIgE) levels are extremely sensitive testing options, but positive test results to tolerated foods are not uncommon. Allergen component-resolved diagnostics (CRD) have the potential to provide a more accurate assessment in diagnosing food allergies. Recently, a number of studies have demonstrated that CRD may improve the specificity of allergy testing to a variety of foods including peanut, milk, and egg. While it may be a helpful adjunct to current diagnostic testing, CRD is not ready to replace existing methods of allergy testing, as it not as sensitive, is not widely available, and evaluations of component testing for a number of major food allergens are lacking.     

The problems of the child with food allergies

In France, about 20% of schoolchildren are suffering from allergic diseases. Food allergy (FA) is steadily increasing for the last 20 years. Actually, 400,000 children are suffering from FA. Prevalence has increased this last decade. Frequency is estimated about 10% and increased twofold within 5 years. In France, the most common food allergens are: hen's egg (35%), peanut (24%), cow's milk (8%), mustard (6%), and fish (4%). Other food allergens as hazelnut, kiwi, wheat, sesame, seafood, and lupin. Cross reactivities to exist between fruits, vegetables pollen, latex and are more and more frequent. Multiple food allergies have recently been described.     

Food allergy diagnosis

The diagnosis of food allergies (FA) relies upon the sequential use of different means and tools, according to a decision tree. Ten clinical characteristics point to a potential FA. A diary for food consumption during a week surveys all labellings, in order to detect masked food allergens. The second step is based on skin prick tests to natural foods, and epicutaneous tests to a few proteins (casein, gluten...). Biological tests using multi detection tests of specific IgEs to numerous allergens are not advised owing to the frequency of clinically not relevant in vitro cross-reactivity. Single determination of specific IgEs, have a 95% predictive positive value of high levels in cases of allergy to milk, egg, fish and peanut, and can spare oral challenges. The primary use of biological tests is not currently advised but may be of interest in litigious cases. Standardized oral challenges are the golden standard. Eviction regimens are an alternative used for cow's milk allergy in infancy, or for suspected digestive allergies in adults.     

Food allergy as a risk factor for asthma morbidity in adults.

BACKGROUND: The objective of this study was to evaluate the relationship between food allergy and asthma morbidity in adults. METHODS: We interviewed a cohort of persistent asthmatics from an inner-city clinic. Allergies to food were assessed by patient report of convincing symptoms of acute allergic reactions. Outcome variables included health resource utilization and medication use. RESULTS: The prevalence of allergy to fish, peanut, tree-nut, shellfish, and seed allergies were 3%, 3%, 3%, 13%, and 1%. Patients with allergies to > 1 food had increased asthma hospitalizations, ED visits, and use of oral steroids (p < 0.05 for all comparisons). Specifically, allergy to fish was associated with a greater risk of health resource utilization and increased frequency of oral steroid use (p < or = 0.03 for all comparisons). CONCLUSIONS: Self-reported allergy to foods was associated with worse outcomes, suggesting that food allergy may be a risk factor for increased asthma morbidity in adults.     

Sensitization to common food allergens is a risk factor for asthma in young Chinese children in Hong Kong.

Sensitization to aeroallergens is a major risk factor for asthma. Although patients frequently consider food ingestion as an asthma trigger, the relationship between serum food-specific IgE antibodies and childhood asthma in China remains unclear. We therefore conducted a case-control study on asthmatic children attending a university hospital-based outpatient clinic to investigate their pattern of food sensitization. Asthmatic patients underwent spirometric assessment, and peripheral blood was collected for serum-specific IgE antibodies to common food and inhalant allergens. Two hundred and thirty-one asthmatics (aged 9.3+/-4.3 years) and 79 age- and sex-matched controls were enrolled. The serum logarithmic total IgE concentrations in patients and controls were 2.49 and 1.92, respectively (p < 0.0001). Subjects with increased serum total IgE level were significantly more likely to have food sensitization than those with normal values (33% vs. 16%; p = 0.001). Twenty-nine (52%) of 56 asthmatics younger than 6 years old and seven (27%) of 26 age-matched controls hadfood-specific IgE in their sera (p = 0.035). Asthmatics with food-specific IgE also used more doses of as-needed bronchodilator weekly (p = 0.005). Nonetheless, no association was found between asthma diagnosis and sensitization to individual food allergens. Significant food sensitization, with food-specific IgE level above 95% predictive values for clinical food allergy as proposed by Sampson, was only found in two patients for peanut and three subjects for egg white. In conclusion, a significant association was found between asthma and the presence of food-specific IgE antibodies in young Chinese children. Significant sensitization to common foods is rare in this cohort.     

Extensively hydrolyzed formula (MA-mi) induced exacerbation of food protein-induced enterocolitis syndrome (FPIES) in a male infant.

BACKGROUND: Food protein-induced enterocolitis syndrome (FPIES) is a severe, cell-mediated food allergy in which digestive symptoms such as severe vomiting and diarrhea are induced by cow's milk and/or soy protein in infants. Generally, a food-specific IgE is not detected, and FPIES may be caused by inadvertent exposure to allergenic foods. CASE SUMMARY: The patient in our case was a male infant in whom vomiting had been induced by ingestion of a cow's milk-based formula and bloody diarrhea had been caused by ingestion of breast milk during the neonatal period. Accidental ingestion of a new and extensively hydrolyzed casein/whey formula, MA-mi, caused watery diarrhea at 8 months of age, and FPIES was diagnosed based on these symptoms. In antigen-specific lymphocyte stimulation tests, New MA-1 was negative, but MA-mi and cow's milk antigens were positive. The only causative antigens were derived from cow's milk, and the symptoms were not induced by another extensively hydrolyzed casein formula, New MA-1. The patient grew and developed normally thereafter, and no symptoms were induced by solid food during the course of the condition. DISCUSSION: MA-mi is likely to be used increasingly for allergic infants, but it is not necessarily a substitute for other hydrolyzed milk formulae in all cases, and care should be taken regarding its use and possible misuse.     

Specific IgE to Common Food Allergens in Children with Atopic Dermatitis

Background: 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. Objectives: 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. Methods: 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. Results: 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. Conclusion: 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.     

Differentiating Food Allergies from Food Intolerances

Adverse reactions to foods are extremely common, and generally they are attributed to allergy. However, clinical manifestations of various degrees of severity related to ingestion of foods can arise as a result of a number of disorders, only some of which can be defined as allergic, implying an immune mechanism. Recent epidemiological data in North America showed that the prevalence of food allergy in children has increased. The most common food allergens in the United States include egg, milk, peanut, tree nuts, wheat, crustacean shellfish, and soy. This review examines the various forms of food intolerances (immunoglobulin E [IgE] and non–IgE mediated), including celiac disease and gluten sensitivity.

Sensitization to Common Food Allergens Is a Risk Factor for Asthma in Young Chinese Children in Hong Kong

Sensitization to aeroallergens is a major risk factor for asthma. Although patients frequently consider food ingestion as an asthma trigger, the relationship between serum food-specific IgE antibodies and childhood asthma in China remains unclear. We therefore conducted a case–control study on asthmatic children attending a university hospital-based outpatient clinic to investigate their pattern of food sensitization. Asthmatic patients underwent spirometric assessment, and peripheral blood was collected for serum-specific IgE antibodies to common food and inhalant allergens. Two hundred and thirty-one asthmatics (aged 9.3±4.3 years) and 79 age- and sex-matched controls were enrolled. The serum logarithmic total IgE concentrations in patients and controls were 2.49 and 1.92, respectively (p<0.0001). Subjects with increased serum total IgE level were significantly more likely to have food sensitization than those with normal values (33% vs. 16%; p = 0.001). Twenty-nine (52%) of 56 asthmatics younger than 6 years old and seven (27%) of 26 age-matched controls had food-specific IgE in their sera (p = 0.035). Asthmatics with food-specific IgE also used more doses of as-needed bronchodilator weekly (p = 0.005). Nonetheless, no association was found between asthma diagnosis and sensitization to individual food allergens. Significant food sensitization, with food-specific IgE level above 95% predictive values for clinical food allergy as proposed by Sampson, was only found in two patients for peanut and three subjects for egg white. In conclusion, a significant association was found between asthma and the presence of food-specific IgE antibodies in young Chinese children. Significant sensitization to common foods is rare in this cohort.     

Prevalence of food allergy in 137 latex-allergic patients.

There have been reports of increased prevalence of certain food allergies in patients with Type I latex allergy (LA). A detailed food allergy history was obtained from 137 patients with LA. Latex allergy was defined by positive history of IgE mediated reactions to contact with latex and positive skin prick test to latex and/or positive in vitro test (AlaSTAT and/or Pharmacia CAP). Food allergy was diagnosed by a convincing history of possible IgE mediated symptoms occurring within 60 minutes of ingestion. We identified 49 potential allergic reactions to foods in 29 (21.1%) patients. Foods responsible for these reactions include banana 9 (18.3%), avocado 8 (16.3%), shellfish 6 (12.2%), fish 4 (8.1%), kiwi 6 (12.2%), tomato 3 (6.1%), watermelon, peach, carrot 2 (4.1%) each, and apple, chestnut, cherry, coconut, apricot, strawberry, loquat, one (2.0%) each. Reactions to foods included local mouth irritation, angioedema, urticaria, asthma, nausea, vomiting, diarrhea, rhinitis, or anaphylaxis. Our study confirms the earlier reports of increased prevalence of food allergies in patients with LA. We also report increased prevalence of shellfish and fish allergy not previously reported. The nature of cross reacting epitopes or independent sensitization between latex and these foods is not clear.     

Food Allergy as a Risk Factor for Asthma Morbidity in Adults

Background. The objective of this study was to evaluate the relationship between food allergy and asthma morbidity in adults. Methods. We interviewed a cohort of persistent asthmatics from an inner-city clinic. Allergies to food were assessed by patient report of convincing symptoms of acute allergic reactions. Outcome variables included health resource utilization and medication use. Results. The prevalence of allergy to fish, peanut, tree-nut, shellfish, and seed allergies were 3%, 3%, 3%, 13%, and 1%. Patients with allergies to > 1 food had increased asthma hospitalizations, ED visits, and use of oral steroids (p < 0.05 for all comparisons). Specifically, allergy to fish was associated with a greater risk of health resource utilization and increased frequency of oral steroid use (p ≤ 0.03 for all comparisons). Conclusions. Self-reported allergy to foods was associated with worse outcomes, suggesting that food allergy may be a risk factor for increased asthma morbidity in adults.     

Glycoprotein A (GARP) in children who outgrow food allergy

BackgroundThere is little understanding of the mechanisms by which food allergy (FA) develops into persistent disease, or by which symptoms it regresses. Food allergy is a major health problem in developed countries, where the prevalence reaches up to 6% in children and 3% in the adult population.ObjectiveChildren with food allergy remission (FAR) and those without FAR below five years of age, were compared 7–10 years with respect to clinical data and expression of glycoprotein A repetitions predominant (GARP) on peripheral blood mononuclear cells.MethodsForty children with FAR and 40 children without FAR at age 7–10, in whom FA was previously diagnosed at age below five years were evaluated. In this prospective study, demographic and clinical data were taken, patients were classified as atopic based on history and serum specific IgE (sIgE) for a specific allergen. Blood samples were obtained from all patients to assess expression of GARP.ResultsWe observed higher expression of GARP in children with FAR compared to children without FA (p = 0.005); optimal cut-off for GARP prediction of the remission was 20.1%. Children with FAR and food-specific IgE in serum had higher expression of GARP compared to children with low food specific IgE (<0.35 kU/L). Keeping pets at home decreased, and presence of allergic rhinitis increased ORs for high expression of GARP (hGARP) in our patients.ConclusionhGARP (>20.1%) is related with FAR in school children. Allergic rhinitis, and pets at home modify this effect of GARP. Children with allergic rhinitis have less chance of developing remission despite maintaining immune tolerance (hGARP); quite the opposite case with pets at home.     

Allergie à lˈarachide

Peanut allergy, which is frequent in the United States and was much less so in Europe up to the mid-eighties, has become a major problem in many industrialized countries. Peanut consumption is high in Eastern Europe, the United Kingdom, The Netherlands, Germany and France. The frequency of peanut allergy is between 0.5 and 0.7% in the general population. Two million Americans are now thought to be affected. In France peanuts are one of the most frequent allergens, lying second (27.4%) to egg in food allergies in children, and holding first place in food allergies in children aged over 3 years. Sensitization occurs through ingestion, contact even if indirect, and inhalation. The symptoms, which affect the skin and the respiratory or gastrointestinal tract, appear a few minutes to a few hours after exposure. Serious reactions (anaphylactic shock, life-threatening reactions, sudden death) have been described. Asthma has a significantly higher association with peanut allergy than with other allergies, taken overall. As with other food allergies, diagnosis is based on history, prick-tests, screening for specific serum IgE and food challenge whose modalities (labial and oral challenge) are debated. For the time being, elimination is the only form of treatment. The development of a modified allergen as immunogenic as possible but practically without allergenic effects should give immunotherapy new impetus. Patients with severe peanut allergy should carry a card or wear a distinctive bracelet indicating their condition as well as an emergency kit including in particular epinephrine.     

Diagnosis of Food Allergy: Epicutaneous Skin Tests, In Vitro Tests, and Oral Food Challenge

Food allergy is becoming an increasingly common diagnosis. Because of this increase in prevalence, it is imperative that physicians evaluating patients with possible adverse reactions to foods understand the currently available assays and how they should best be used to accurately diagnose the disease. Simple tests such as skin prick testing (SPT) and serum food-specific IgE testing are the most commonly used diagnostic tests to evaluate for IgE-mediated food reactions. However, these tests, which measure sensitization and not clinical allergy, are not without pitfalls, and their utility must be appreciated to avoid over- and underdiagnosis. Although the physician-supervised oral food challenge remains the gold standard for food allergy diagnosis, a careful medical history paired with SPT and serum food-specific IgE testing often can provide a reliable diagnosis. In this review, we examine the usefulness and pitfalls of SPT and serum food-specific IgE levels, as well as examine atopy patch testing and other emerging tests, such as component-resolved diagnostics and the basophil activation test. Finally, we describe the use of the double-blind, placebo-controlled oral food challenge as the current gold standard for food allergy diagnosis.     

Use of an amino-acid-based formula in the treatment of cow's milk protein allergy and multiple food allergy syndrome

Food allergy to cow's milk proteins (APLV) is frequently found in young infants. Treatment is by starting an elimination diet. Different substitution products have been proposed: soya milk, partial hydrolysate of the proteins of lactoserum, powdered casein hydrolysate, hydrolysed soya and pork collagen. Allergic reactions to soya milk, hydrolysates of lactoserum proteins, powdered casein hydrolysates and hydrolysates of soya have been described. The study that we present evaluates the effect on the natural development of these allergies of a formula based on amino-acids (Neocate) in 26 patients who presented a syndrome of multiple allergies one of which was a food allergy to milk. Twenty-five of them had a severe atopic dermatitis, isolated (14 cases), or associated with gastro-intestinal troubles (6) break in the growth curve (5), anaphylactic reactions (2), one asthma (1). One child had a chronic diarrhoea associated with a weight plateau. Evaluation 2 or 3 months later showed a significant improvement of the atopic dermatitis. Return of the stature-weight growth was noted in 4 children from 5, the check in one was reported as due to a initially unrecognised allergy to gluten. The recovery of the APLV was shown by double-blind oral provocation test in 20/23 children between 11 and 37 months (22 +/- 9). Duration of administration of Neonate was between 6 to 19 months (12 + 5) months. This study confirmed the beneficial effect of the amino-acid formula on weight gain, gastro-intestinal troubles and development of atopic dermatitis. The level of recovery of APLV of 86% at the age of 2 years is better than that reported in the syndrome of multiple food allergies of 22%. The influence of this diet on the development of other food allergies remains to be evaluated.     

Arachide,fruits secs oléagineux : réalité clinique,conséquences sociales

The frequency of allergic reactions to peanut and tree nuts has increased. The cumulated prevalence of peanut allergy is high, 0.5 to 1.2% in American and Western European children; the prevalence of tree nut allergy is 0.5%. Allergic reactions to peanut and tree nuts can be life threatening. This problem is widely discussed in the media. Sensitization to tree nuts should be investigated in children with allergy to peanut or to any other nut. Evaluation  of the patient must take into account the clinical data and the results of skin tests, specific IgE assays and labial provocation tests. The decision of whether to perform a provocation challenge should be individualized. Children, particularly adolescents, at risk for severe reactions include those with multiple allergies, asthma, especially uncontrolled asthma, or facilitating factors such as drugs (including aspirin), alcohol and exercice. At present, prevention calls for avoidance of peanuts and tree nuts. Global management and careful education are essential and should be tailored to each child and its family. Management of severe food allergies must be comprehansive and must consist of more than just epinephrine.     

Egg and milk allergy in asthmatic children: assessment by immulite allergy food panel, skin prick tests and double-blind placebo-controlled food challenges

There is a perception that asthmatic symptoms may be worsoned by ingestion of certain foods. This study aimed to investigate whether ingestion of cow's milk or egg might induce respiratory symptoms in asthmatic children. Fifty asthmatic children aged 1.5 to 6 years old, with positive Immulite Food Panel FP5 test results were included in the study. Fifty healthy children within the same age group were accepted as control group. Total serum IgE levels were measured and skin prick tests for food allergens including milk and egg were performed. All of the subjects underwent oral, double-blind, placebo-controlled challenge with fresh egg and cow's milk powder. Two medical histories were confirmed by double-blind, placebo-controlled challenge in 9 patients (22.2%). Skin prick tests were positive in 9 patients (18%) with milk and 18 patients (36%) with egg antigen. Two children experienced wheezing, one after ingesting milk and the other after egg challenge (4%). In the control group no positive reactions were seen with egg or milk challenges. Our findings confirm that food allergy can elicit asthma in children, but its incidence is low, even with major allergens such as egg and milk. History, specific IgE determinations and skin prick tests are not reliable in diagnosing food reactions. Since any diet can cause rapid deficiencies in infancy, diet restrictions must not be applied, without performing double-blind, placebo-controlled challenge.     

Meeting the nutritional needs of the low-birth-weight infant

Approximately 5% of young children and 3-4% of adults exhibit adverse immune responses to foods in westernized countries, with a tendency to increase. The pathophysiology of food allergy (FA) relies on immune reactions triggered by epitopes, i.e. small amino-acid sequences able to bind to antibodies or cells. Some food allergens share specific physicochemical characteristics that allow them to resist digestion, thus enhancing allergenicity. These allergens encounter specialized dendritic cell populations in the gut, which leads to T-cell priming. In case of IgE-mediated allergy, this process triggers the production of allergen-specific IgE by B cells. Tissue-resident reactive cells, including mast cells, then bind IgE, and allergic reactions are elicited when these cells, with adjacent IgE molecules bound to their surface, are re-exposed to allergen. Allergic reactions occurring in the absence of detectable IgE are labeled non-IgE mediated. The abrogation of oral tolerance which leads to FA is likely favored by genetic disposition and environmental factors (e.g. increased hygiene or enhanced allergenicity of some foods). For an accurate diagnosis, complete medical history, laboratory tests and, in most cases, an oral food challenge are needed. Noticeably, the detection of food-specific IgE (sensitization) does not necessarily indicate clinical allergy. Novel diagnostic methods currently under study focus on the immune responses to specific food proteins or epitopes of specific proteins. Food-induced allergic reactions represent a large array of symptoms involving the skin and gastrointestinal and respiratory systems. They can be attributed to IgE-mediated and non-IgE-mediated (cellular) mechanisms and thus differ in their nature, severity and outcome. Outcome also differs according to allergens.