A review on food allergy: pathogenesis, diagnosis methods and treatment approaches

An exaggerated immune reaction to a food that takes place in a vulnerable host is referred to as a food allergy. The two main types of food-induced allergy diseases are those caused by Immunoglobulin E (IgE) antibodies and those caused by non-IgE-mediated mechanisms. These reactions are frequently brought on by food allergens such as egg, seafood, fruits, milk, soy, peanut, etc. In India, roughly 26.5% of the population has been impacted by food-induced allergy diseases. Age, sex, heredity, and geographic location of the patient, as well as vitamin D deficiency and other allergic reactions, are risk factors that might result in life-threatening food allergies. Skin prick test, oral food challenge, component resolved diagnostic testing are the most widely used diagnostic tests for food allergy. Pharmacotherapy of food induced allergic reactions include epinephrine therapy and use of antihistamine drugs. However, the main stay of treatment is avoidance of responsible food and food desensitization. Some home remedies can also be used in order to control allergic reactions caused by food allergens. All these remedies directly or indirectly improve the health of immune system to prevent food induced allergic reactions. The objective of this study was to throw a light on the pathogenesis, diagnostic methods and possible treatment options for food allergy.

Alergias alimentarias en pediatría: frecuencia, características clínicas y alergenos más frecuentes en pacientes de un consultorio pediátrico de alergia de referencia

RESUMEN Introducción: Las alergias alimentarias constituyen una patología cada vez más frecuente en la infancia. Es importante conocer sus características para su prevención y mejor abordaje terapéutico. Objetivo: Determinar la frecuencia, las características clínicas y los tipos de alimentos desencadenantes de las alergias alimentarias más frecuentes, en pacientes pediátricos en un consultorio de referencia, entre marzo 2016-marzo de 2019. Materiales y Métodos: estudio transversal, descriptivo, observacional con datos secundarios de fichas clínicas de pacientes de menores de 18 años. Se estudiaron edad, sexo, manifestaciones clínicas y tipo de alergeno alimentario desencadenante, detectado por RAST. Resultados: La mediana de edad de diagnóstico fue de 10 meses, fueron lactantes 52(73%) pacientes, 10(14%) fueron prescolares y el resto escolares y adolescentes; 43(60%) fueron varones. Las lesiones cutáneas estuvieron presentes (aisladas o combinadas con otros síntomas) en 46 casos (64%); los síntomas respiratorios en 38 casos (53%); gastrointestinales en 30 casos (42,2%). La leche fue el alergeno alimentario detectado en 52 (73%) pacientes, el huevo en 33 (46%), el trigo en 7(9,8%), la soja en 6(8,5%), el gluten en 5(7%); las golosinas, el maní, el maíz y los embutidos en 2 (2,8%) niños y finalmente la sandía, el tomate y los condimentos en 1(1,4%) caso. Se registró un único alérgeno en 46 casos (64,7%), dos alérgenos en 16 casos (22,5%), tres alérgenos en 5 casos (7%), y más de tres alérgenos en 4 casos (5,6%). Conclusiones: Los lactantes son los más afectados por las alergias alimentarias siendo más prevalentes los síntomas cutáneos y digestivos. La proteína de leche de vaca es el alergeno más frecuente seguido por el huevo.

ABSTRACT Introduction: Food allergies are an increasingly frequent pathology in childhood. In order to prevent them and to offer a better therapeutic approach, it is important to characterize them. Objective: To determine the frequency, clinical characteristics and types of foods that trigger the most frequent food allergies, in pediatric patients at a referral clinic, between March 2016-March 2019. Materials and Methods: This was a cross-sectional, descriptive, observational study with secondary data from clinical records of patients under 18 years of age. Age, sex, clinical manifestations and type of triggering food allergen, detected by RAST, were studied. Results: The median age of diagnosis was 10 months, 52 (73%) patients were infants, 10 (14%) were preschool and the rest were schoolchildren and adolescents; 43 (60%) were male. Skin lesions were present (isolated or combined with other symptoms) in 46 cases (64%); respiratory symptoms in 38 cases (53%); gastrointestinal in 30 cases (42.2%). Milk was the food allergen detected in 52 (73%) patients, egg in 33 (46%), wheat in 7 (9.8%), soy in 6 (8.5%), gluten in 5 (7%); sweets, peanuts, corn and sausages in 2 (2.8%) children and finally watermelon, tomato and condiments in 1 (1.4%) case. A single allergen was recorded in 46 cases (64.7%), two allergens in 16 cases (22.5%), three allergens in 5 cases (7%), and more than three allergens in 4 cases (5.6%). Conclusions: Infants are the most affected by food allergies, skin and digestive symptoms are more prevalent. Cow's milk protein is the most common allergen followed by eggs.

Métodos electroforético e inmunoquímicos para detectar proteínas de leche, soja y huevo en premezclas comerciales / Electrophoretic and immunochemical methods for the detection of milk, soy and egg proteins in commercial mix products

The presence of milk, egg and soy proteins was evaluated in thirteen commercial products, which were premixes to make cream caramel, cake, soy "milanesas", "tortas fritas", pizza, gnocchi and complementary foods. Samples were analysed using SDS-PAGE, immunoblotting and ELISA methods. The electrophoretic method and immunoblotting were useful to confirm the presence of milk, egg and soy proteins in four samples that declared them as ingredients. In other samples, both methods showed negative results for some of these proteins, although they were also declared as ingredients. This suggests that those proteins were not added as ingredients in these products. The ELISA kits detected very low concentration of the allergenic proteins in four products with precautionary phrases and also in five samples that made no reference to them in their labels. ELISA methods are useful to detect cross contamination due to their high sensitivity. The food industry should be responsible for the declaration of milk, egg and soy proteins in their food labels.

Se evaluó la detección de proteínas de leche, huevo y soja en trece productos comerciales, correspondientes a premezclas para preparar flanes, bizcochuelo, milanesas de soja, tortas fritas, pizza, ñoquis y productos en polvo a base de harinas para niños pequeños. Las muestras fueron analizadas por SDS-PAGE, inmunoblotting y métodos de ELISA. El método electroforético e inmunoblotting resultaron útiles para confirmar la presencia de las proteínas alergénicas en algunas muestras que las declaraban como ingredientes. En cuatro muestras que también declaraban como ingredientes alguna de estas proteínas, tanto con SDS-PAGE como con Inmunoblotting, los resultados fueron negativos, sugiriendo que dichas proteínas no fueron agregadas como ingredientes en dichos alimentos. Los kits de ELISA permitieron la detección de concentraciones muy bajas de estos alérgenos en cuatro productos que presentaban frases de advertencia e incluso en otros cinco que no tenían ninguna declaración de alérgenos. Los métodos de ELISA son útiles para detectar contaminaciones cruzadas, dada su elevada sensibilidad. Se concluye que resulta necesario una declaración responsable de estas proteínas alergénicas, en los rótulos de este tipo de alimentos por parte de los fabricantes.

Determinação de IgE a alérgenos alimentares por microarray (ImmunoCAP-ISAC) em pacientes com rinite alérgica / Evaluation of IgE antibodies to food allergens in patients with allergic rhinitis using microarray analysis (ImmunoCAP ISAC)

Objetivo: Determinar a frequência de anticorpos IgE a alérgenos alimentares em pacientes com doenças alérgicas respiratórias por análise molecular. Método: Este estudo transversal incluiu 101participantes, com idades entre 6-18 anos, com diagnóstico de rinite alérgica (89,1% com asmaassociada), sem história de alergia alimentar. Foi realizada análise de IgE sérica específica por ImmunoCAP ISAC, método que emprega biologia molecular para detecção de IgE a componentes alergênicos, sendo 42 alimentares e provenientes das seguintes fontes: abacaxi, aipo, amendoim,avelã, bacalhau, camarão, carpa, castanha de caju, castanha do Pará, cenoura, gergelim, kiwi, leite de vaca, maçã, ovo, pêssego, soja e trigo. Valores ≥ 0,3 ISU (unidades padronizadas do ISAC) foram considerados positivos. Utilizou-se análise estatística descritiva. Resultados: Vinte e sete (26,7%)pacientes apresentaram IgE específica a pelo menos um dos alérgenos alimentares analisados.Entre os 42 componentes alergênicos testados, 20 (47,6%) foram associados a resposta IgE em pelo menos um dos pacientes. Alérgenos com maior frequência de reatividade IgE foram: camarão(Pen a 1 15,8%, Pen i 1 16,8%, Pen m 1 16,8%) e pêssego (Pru p 3 5,9%). Conclusões: Este estudo demonstrou que a avaliação de alergia alimentar baseada em análise molecular deve considerar vários elementos, particularmente a correlação com os sintomas clínicos, e o conhecimento sobre reatividade cruzada IgE entre alérgenos das mais variadas fontes. Presença de IgE específica a determinado componente alergênico significa sensibilização, e não necessariamente alergia.Diagnóstico incorreto de alergia alimentar pode levar a tratamento inadequado, com dietas restritivas desnecessárias e prejuízo nutricional para os pacientes.

Objective: To determine the frequency of IgE antibodies to food allergens in patients with respiratory allergic diseases using molecular analysis. Method: This cross-sectional study included101 participants aged 6-18 years, diagnosed with allergic rhinitis (89.1% with associated asthma),and with no history of food allergy. Analysis of serum specific IgE was carried out using the ImmunoCAP ISAC method, which applies molecular biology tools to the detection of different allergens, including 42 derived from foods (pineapple, celery, peanut, hazelnut, codfish, shrimp,carp, cashew nut, Brazil nut, carrot, sesame, kiwi, cow’s milk, apple, egg, peach, soy, and wheat).Values ≥ 0.3 ISAC standardized units (ISU) were considered to be positive. Descriptive statistical analysis was used. Results: Twenty seven (26.7%) patients presented specific IgE to at leastone of the food allergens analyzed. Among the 42 allergic components tested, 20 (47.6%) were associated with IgE responses in at least one patient. The allergens with the highest frequencies of IgE reactivity were shrimp (Pen a 1 15.8%, Pen i 1 16.8%, Pen m 1 16.8%) and peach (Pru p 3 5.9%).Conclusions: The present study showed that molecular-based evaluation of food allergies should take several elements into consideration, particularly the correlation with clinical symptoms andthe knowledge available on IgE cross-reactivity among allergens from different sources. Presence of specific IgE to one allergen means sensitization, but not necessarily allergy. Misdiagnosis of food allergies may lead to inappropriate treatment, with unnecessarily restrictive diets which could affect the nutritional status of patients.

Analysis of allergens in 5 473 patients with allergic diseases in Harbin, China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To analyze the allergic status to common inhalant allergens and food allergens in clinical patients in Harbin in northeastern China and provide evidence to develop the prevention strategy of allergic disease.</p><p><b>METHODS</b>The data were collected from 5 473 patients with clinical suspected allergic diseases seeking medical care in the Second Affiliated Hospital of Harbin Medical University. Among these patients, 2 530 (46.2%) were males aged 0-86 years, the youngest was only 1 month old and 2 579 (47.1%) were young children and teenagers. The serum specific Immunoglobulin E (sIgE) to 14 kinds of common allergens and serum total IgE were detected by using AllergyScreen test (Mediwiss Analytic GmbH, Moers, Germany).</p><p><b>RESULTS</b>In 5 473 subjects the positive rate of sIgE was 33.1% (n=1 813). Cow milk (6.9%) and wheat (3.1%) were the most common food allergens, followed by house dust mite mix (12.5%) and mould mix (9.4%) and the age and gender specific differences in the positive rate were significant. For the children aged <7 years the positive rates to cow milk, beef-mutton, and egg white/egg yolk were high, but the positive rates to house dust mite mix, ragweed estragon, and mould mix were low (P<0.05). For the adults the positive rates to aeroallergens were high while the rates to food allergens were low.</p><p><b>CONCLUSION</b>The results from this study showed that the food allergens in Harbin had geographic characteristics, which support the viewpoint that the environment factors play an important role in the incidence of allergic diseases. Also, the detection of sIgE and total IgE are essential to identify relevant allergens for the purpose of early diagnosis, management and prevention of allergic disease.</p>

Clinical application of examination of specific IgG4 to food allergens / 临床检验杂志

Objective To investigate the clinical application of examination of specific IgG4 to food allergens.Methods Specific IgG4 as well as specific IgE to ten kinds of food allergens in sera of 51 patients with chronic eczema was examined by ELISA.Results Food allergen specific IgG4 was positive in 35 patients (68.6%) and food allergen specific IgE was positive in 45 patients(88.2%)of the 51 cases (P

Food Allergy / 소아과

Food allergy is one of the clinical clusters due to food-induced allergic inflammation against dietary proteins which induced by IgE-mediated and/or non-IgE mediated mechanisms. Food allergic reactions are responsible for a variety of clinical symptoms involving the skin, gastrointestinal tract, and respiratory tract. Sometimes the life threatening anaphylactic reactions would be induced, especially by peanuts, tree nuts and buckwheat allergy. Up to 8% of children less than 3 years of age, and up to 2% of adult population experienced food allergic diseases. A limited number of foods are responsible for the vast majority of food allergic reactions in clinically. Cow's milk, egg, soybean, peanuts, tree nuts, fish, shellfish are the major allergenic foods. Especially in infant and young children, the IgE sensitization to cow's milk, egg, and soybeans are most prevalent, and buckwheat allergy is relatively frequent in Asian countries including Korea. Proper diagnoses often require screening tests for evidence of food-specific IgE(Skin prick test, detection of serum allergen specific IgE over cut-off values) and proof of reactivity through elimination diets and oral food challenges. Recently, the diagnostic decision points of serum specific IgE levels were defined for several kinds of food allergies(egg white, cow's milk, soybeans, peanut, wheat, fish, buckwheat), and the use of these optimal cutoff levels would be helpful for avoiding unnecessary risky challenge in children with a strong clinical history and skin test responses. Once food allergy is properly diagnosed, strict avoidance of the implicated food(s) and containing products is the only proven form of treatment. Clinical or immunilogical tolerance to food allergens will develop in many patients over time(usually need more than 3 years of strict avoidance), and therefore follow-up serologic tests and/or food challenges are often indicated for avoiding unnecessary long term duration of avoidance in cases.

The sensitization rates of food allergens in a Korean population: a multi-center study / 천식및알레르기

BACKGROUND: Sensitization to food allergens is associated with development of food allergy. Although rates of sensitization to food allergens are different according to countries, there has not been surveyed on the sensitization rate to each food allergen in Korean population. The aim of this study was to evaluate the food allergen sensitization rate among patients who visited allergy clinics at several university hospitals in Korea. METHODS: This study was carried out on 1,425 patients who visited allergy clinics with various allergic symptoms. They had skin prick test for 62 items to evaluate sensitization to food allergens. RESULT: The food allergens of which sensitization rate was above 1% were pupa of a silkworm, shrimp, chestnut, curry, potato, soybean, rice flour, buckwheat, cabbage, mackerel, abalone, lobster, turban shell, arrowroot in decreasing order. The sensitization rate of pupa was highest among them by 9.4% and that of shrimp followed by 5.8%. The sensitization rates of food allergens were generally higher in males and young adults than in those of females and old people. Atopic patients for inhalant allergens showed higher sensitization rates of food allergens than non-atopic patients for inhalant allergens. CONCLUSION: Common food allergens sensitized in a Korean population were different from those in other countries. Pupa of a silkworm, shrimp, chestnut, curry, potato, soybean, rice flourbuckwheat, cabbage, mackerel were the 10 most common food allergens sensitized in Korean population above 10 years old.