Eventos adversos imediatos à vacina febre amarela em crianças alérgicas ao ovo / Immediate adverse events to the yellow fever vaccine in egg-allergic children

Introdução: A vacina contra a febre amarela é cultivada em ovos embrionados de galinha e por isso pode estar contraindicada em indivíduos alérgicos ao ovo. Quando indicada, deve ser aplicada com cautela, após atendimento especializado para avaliação de testes e necessidade de dessensibilização. Sua segurança nos alérgicos ao ovo ainda é pouco estudada. Objetivo: Descrever uma população pediátrica encaminhada por alergia ao ovo, com ou sem diagnóstico comprovado, e os casos de eventos adversos do tipo imediata à vacina contra a febre amarela em um centro de referência para imunobiológicos especiais (CRIE). Material e métodos: Estudo transversal realizado com coleta de dados retrospectivos de crianças entre 9 meses e 12 anos de idade, vacinadas contra a febre amarela com história de alergia ao ovo, no período de 2018 a 2019. Resultados: Dentre as 829 crianças, com diagnóstico presumido de alergia ao ovo, foi identificada uma maior prevalência de sintomáticos após exposição ao ovo, com IgE específica detectável para ovo, clara de ovo e/ou ovoalbumina. Testes para vacina febre amarela foram realizados em 25 crianças com suspeita de alergia grave ou anafilaxia ao ovo, sendo 15 (60%) positivos com a vacina aplicada após dessensibilização. Foram evidenciados apenas 11 (1,3%) casos de evento adverso imediato à vacina, todos classificados como evento adverso não grave e com acometimento especial da pele (reação local e exantema ou urticária). A maioria dos eventos ocorreu em menores de 2 anos, nos sintomáticos após ingesta de ovo e naqueles com altos valores de IgE específica para clara de ovo. Conclusão: Este estudo evidencia que a vacina contra a febre amarela pode ser aplicada em crianças alérgicas ao ovo, de forma segura, inclusive naquelas com história de anafilaxia, desde que em ambiente adequado e com profissionais especializados.

Introduction: The yellow fever vaccine is grown in embryonated chicken eggs and may be contraindicated for egg-allergic individuals. When indicated, it should be applied with caution, after testing and desensitization. Its safety in egg-allergic patients is still poorly studied. Objective: To describe a pediatric population referred for egg allergy, with or without a confirmed diagnosis, and cases of immediate-type adverse events to the yellow fever vaccine at a reference center for special immunobiologicals. Material and methods: This cross-sectional study collected retrospective data from children between 9 months and 12 years of age who were vaccinated for yellow fever between 2018 and 2019 and had a history of egg allergy. Results: In the 829 children diagnosed with presumed egg allergy, a higher prevalence of symptoms was identified after egg exposure, with detectable specific IgE for egg, egg white, and/ or egg albumin. Yellow fever vaccine tests were performed in 25 children suspected of severe allergy or anaphylaxis to eggs, and 15 (60%) tested positive to the vaccine after desensitization. Only 11 (1.3%) cases of immediate adverse events to the vaccine occurred, all classified as non-serious events that especially involved the skin (local reaction and rash or urticaria). Most events occurred in children under 2 years of age, those symptomatic after egg ingestion, and those with high levels of specific IgE to egg white. Conclusion: This study demonstrated that the yellow fever vaccine can be safely administered to egg-allergic children, including those with a history of anaphylaxis, in an appropriate environment and with specialized professionals.

Alergia alimentar ao leite de vaca e ovo mediadas por IgE: sugestões de receitas termicamente testadas / IgE-mediated food allergy to cow's milk and egg: baked recipe suggestions

Objetivo: Cerca de 50% dos indivíduos com alergia ao leite de vaca e ao ovo podem tolerar esses alimentos em sua forma termicamente tratada. O consumo desses alimentos, mesmo que termicamente tratados, pode ampliar a variedade da dieta de crianças com alergia alimentar. O presente artigo tem como objetivo propor receitas culinárias com leite de vaca e ovo tratados termicamente para serem usadas em teste de provocação oral. Métodos: Alguns critérios foram adotados para elaboração das receitas: quantidade de proteína alergênica testada por porção (leite de vaca - 1,3 g; ovo - 2,0 g), tempo (30 minutos), temperatura de cocção (180 °C), os ingredientes que devem compor a receita (farinha de trigo como principal ingrediente), volume final da porção a ser oferecida, além de questões de ordem prática relacionadas ao preparo e oferta das preparações. Resultados: No total foram desenvolvidas dez receitas termicamente tratadas, sendo cinco com leite de vaca (três receitas de bolinho ­ básica, sem açúcar e sem ovo de galinha; duas receitas de tortinha salgada ­ básica e sem ovo de galinha) e cinco com ovo de galinha (três receitas de bolinho ­ básica, sem açúcar, e sem leite de vaca; duas receitas de tortinha salgada ­ básica e sem leite de vaca). Conclusão: É de extrema importância que o teste de provocação oral seja realizado de maneira rotineira e com preparações adequadas e padronizadas, e, em nosso conhecimento, esse é o primeiro estudo nacional que propõe várias receitas tratadas termicamente para auxiliar serviços especializados que atendem pacientes com alergia alimentar.

Objective: About 50% of individuals with cow's milk and egg allergies can tolerate these foods in their baked form. The consumption of these foods, even if baked, may expand the variety of the diet of children with food allergy. This article aims to propose recipes with baked milk and egg to be used in an oral food challenge. Methods: Some criteria were adopted for preparing the recipes: amount of allergenic protein tested per serving (cow's milk: 1.3 g; egg: 2.0 g), time (30 min), oven temperature (180 °C), the ingredients that should compose the recipe (wheat flour as the main ingredient), final volume of the serving to be provided, in addition to practical questions related to the preparation and provision of the recipes. Results: In total, ten baked recipes were developed, five with cow's milk (three cupcake recipes: regular, with no sugar and no egg; two savory muffin recipes: regular, with no egg) and five with egg (three cupcake recipes: regular, with no sugar and no cow's milk; two savory muffin recipes: regular, with no cow's milk). Conclusion: It is extremely important that the oral food challenge is performed routinely and with adequate and standardized recipes. To our knowledge, this is the first national study in Brazil that proposes several baked recipes to assist specialist services that treat patients with food allergy.

Segurança da vacina de febre amarela em pacientes comprovadamente alérgicos à proteína do ovo / Safety of yellow fever vaccine in egg allergic patients

Introdução: A vacina de febre amarela, recomendada em áreas endêmicas, é contraindicada em alérgicos à proteína do ovo (APO) por ser cultivada em ovos de galinha embrionados. Objetivo: O objetivo do estudo foi mostrar a segurança da vacina de febre amarela em pacientes comprovadamente APO. Método: Foi realizado estudo prospectivo em hospital quaternário, no período de janeiro a outubro de 2018. Foram incluídos pacientes com APO confirmada por teste de provocação oral (TPO), reação anafilática à proteína do ovo nos últimos 6 meses, ou reação de APO nos últimos 2 meses associada à IgE específica positiva. Todos foram submetidos ao teste de puntura com a vacina na apresentação pura. Se negativo, realizado teste intradérmico (ID) com a vacina na diluição de 1:100. Se ID negativo, vacina aplicada em dose plena. Se teste de puntura ou ID positivo, vacina aplicada fracionada segundo protocolo de dessensibilização. Resultados: Dos 78 pacientes com história presumida de APO, confirmou-se o diagnóstico em 43 (30M:13F, mediana idade 2,7 a): 30 por TPO, 7 com anafilaxia em menos de 6 meses da vacina, e 6 com reação imediata após ingestão do ovo há menos de 2 meses e IgE específica positiva. Durante o TPO, 12 apresentaram anafilaxia, e os demais (18) apresentaram urticária e/ou angioedema ou vômitos. Todos os testes de puntura (43) foram negativos. ID foi negativo em 37 pacientes, que receberam a dose plena da vacina, sem reações. Apenas 6 apresentaram ID positivo e necessitaram dessensibilização para vacina. Metade desses pacientes (3/6) apresentou reações de hipersensibilidade leves e foi tratada com anti-H1 e/ou corticoide oral. O ID positivo foi significativamente relacionado à reação à vacina (p = 0,0016). Conclusão: Concluiuse ser possível vacinar alérgicos a ovo, com um protocolo seguro, mesmo em paciente comprovadamente anafilático. É necessária uma unidade especializada para sua realização, com capacidade de controlar possíveis situações de risco.

Introduction: The yellow fever vaccine (YFV) is recommended in endemic areas, but represents a risk for egg allergic (EA) patients, as it is cultivated in chicken embryos. Objective: This study aimed to describe the outcomes of YFV in patients with confirmed egg allergy. Methods: A prospective study was conducted in a quaternary hospital, from January to October 2018. EA was diagnosed through oral food challenge (OFC) or recent history of anaphylaxis following egg contact in the past 6 months or allergic reaction in the past 2 months with positive specific immunoglobulin E (IgE). Skin prick testing (SPT) with YFV was performed in all participants. If SPT was negative, an intradermal test (IDT) was performed at 1:100 dilution. If IDT was negative, a full dose of YFV was administered. If SPT was positive, the YFV was administered using a graded-dose protocol. Results: Among 78 patients with prior history of EA, 43 were confirmed (30 male to 13 female, median age of 2.7 years). Thirty patients had a positive OFC, seven reported recent anaphylaxis, and six had reactions in the past 2 months with positive specific IgE. During OFC, 12 patients had anaphylaxis and 18 had urticaria and/or angioedema or vomiting. SPT with YFV was negative in all patients (43). IDT was negative in 37 patients, who received a full dose of YFV, uneventfully. Six patients had a positive IDT and received the YFV in graded doses; half of them had a mild reaction controlled with antihistamines and three patients received the vaccine without reactions. Positive IDT was significantly related to vaccine reaction (p=0.0016). Conclusion: The YFV using a specific protocol was safe even in anaphylactic patients. An appropriate setting is required in order to control possible adverse events.

Receitas para teste de provocação oral duplo-cego, controlado por placebo / Recipes for double-blind, placebo-controlled oral food challenge

Introdução: O teste de provocação oral (TPO) é o método mais confiável para verificar a relação entre o consumo de um alimento e o desencadeamento de reações adversas. Dentre as dificuldades na realização do TPO, destaca-se o mascaramento dos alimentos em TPO duplo-cego, controlado por placebo (TPODCCP). Objetivo: O objetivo deste trabalho foi elaborar receitas para uso em TPO-DCCP com leite de vaca, soja, ovo e trigo. Métodos: A elaboração das receitas considerou a necessidade de mascaramento do alimento a ser testado, de modo que a receita real e o placebo fossem indistinguíveis. Foram considerados também a quantidade de alimento a ser testado e o volume final das preparações, bem como a hipoalergenicidade dos demais ingredientes utilizados. Resultados: Foram desenvolvidas cinco receitas para TPO-DCCP, sendo duas para testes com leite de vaca, e as outras para testes com soja, ovo e trigo. As receitas placebo e real ficaram semelhantes em relação às cores, texturas, consistências, sabores e aromas. Conclusão: As receitas aqui apresentadas são de preparo fácil e rápido e atendem à maioria dos critérios exigidos para uso em TPO com alimentos. Há, porém, a necessidade de testá-las em estudos de validação para verificarse a possibilidade de serem usadas em protocolos científicos.

Introduction: Oral food challenge (OFC) is the most reliable method to assess the relationship between food consumption and onset of adverse reactions. Among the difficulties in performing OFC there is the masking of food in double-blind, placebocontrolled OFC (DBPC-OFC). Objective: The objective of this study was to prepare recipes to be used in DBPC-OFC with cow's milk, soy, egg and wheat. Methods: Recipe preparation focused on the need of masking the food to be tested, so that actual and placebo recipes were indistinguishable. Also, the amount of food to be tested and the final volume of preparations were considered, and the hypoallergenicity of other ingredients, as well. Results: Five recipes were developed for DBPC-OFC, two for cow's milk tests and the others for soy, egg and wheat tests. Placebo and actual recipes were similar in color, texture, consistency, taste and flavor. Conclusion: The present recipes are quick and easy to prepare and meet most of the criteria required for use in OFC. However, there is the need to test them in validation studies to assess the possibility of use in scientific protocols.

Reduction Rate of Specific IgE Level as a Predictor of Persistent Egg Allergy in Children

PURPOSE: Egg is the most common food allergen in infants. However, the natural course of egg allergy has not been fully elucidated. This study aimed to describe clinical characteristics and to identify prognostic factors associated with tolerance acquisition of immunoglobulin E (IgE)-mediated egg allergy in children.

Frecuencia de las reacciones alérgicas a la vacuna triple viral en pacientes con alergia al huevo / The frequency of allergic reactions to the triple viral vaccine in 94 patients with egg allergy

Introducción. La vacunación es la intervención en salud pública más efectiva de todos los tiempos, pues reduce la mortalidad y la morbilidad de múltiples enfermedades infecciosas. En muchas ocasiones, la aplicación de las vacunas se retrasa por el temor a las reacciones alérgicas, lo cual es frecuente entre los pacientes con alergia al huevo que requieren la vacuna triple viral (rubeola-sarampión-parotiditis). Objetivo. Evaluar la frecuencia de reacciones después de la aplicación de la vacuna triple viral en una población alérgica al huevo. Materiales y métodos. Se hizo un estudio retrospectivo multicéntrico (2014-2016) de pacientes con alergia al huevo que acudieron a centros de alergología de Medellín y requerían la aplicación de la vacuna triple viral. Resultados. Noventa y cuatro pacientes cumplían los criterios de selección; 68,2 % de ellos presentaba síntomas cutáneos al consumir huevo; 22,3 %, reacción anafiláctica; 5,3 %, síntomas gastrointestinales, y 4,2 %, síntomas respiratorios. Independientemente de la gravedad de su reacción al huevo, todos los pacientes recibieron la vacuna triple viral y la toleraron bien. Conclusión. Aunque la alergia al huevo es frecuente en la edad infantil, el riesgo de reacciones alérgicas después de aplicar la vacuna triple viral en esta población fue similar al de la población general, por lo que no se debe diferir su aplicación, incluso en pacientes con antecedentes de reacciones graves al huevo.

Introduction: Vaccination is the most effective public health intervention of all times, reducing the death and morbidity rates derived from multiple infectious diseases. In many cases, the administration and reception of vaccines is delayed due to the fear of allergic reactions; this is frequent among patients with allergy to egg who need the triple viral vaccine. Objective: To evaluate the frequency of reactions after the administration of triple viral vaccine (Measles, Mumps and Rubella, MMR) in an egg-allergic population. Materials and methods: We conducted a multi-center retrospective study (2014-2016) including patients with egg allergy who visited an allergology center and required the administration of the triple viral vaccine. Results: A total of 94 patients met the selection criteria. From these patients, 68.2% had cutaneous symptoms, 22.3% had an anaphylactic reaction, 5.3% had gastrointestinal symptoms, and 4.2% had respiratory egg-related symptoms. Regardless of the severity of their reaction to egg, all patients received the triple viral vaccine and in 100% of the cases, it was well tolerated. Conclusion: Although egg allergy is common in childhood, the risk of allergic reactions during the MMR vaccination in this population was similar to that in the general population, therefore, its use should not be deferred even in patients with a history of severe egg-related allergic reactions.

Effect of atopic dermatitis on the natural course of food allergy in infants and young children

PURPOSE: There have been studies showing that food allergy plays a role in the pathogenesis of atopic dermatitis. However, there have been few studies about the effect of atopic dermatitis on remission of food allergy. Thus, this study aimed to evaluate the difference in remission according to the presence of atopic dermatitis in infants and young children with milk or egg allergy. METHODS: A retrospective study was performed on 109 infants and young children with IgE-mediated food allergy in a tertiary hospital. They divided into food allergy with atopic dermatitis (FA with AD) and without atopic dermatitis (FA without AD). RESULTS: In the milk allergy group, initial milk-specific IgE levels were 21.16±27.98 kU(A)/L and 11.36±22.88 kU(A)/L, respectively, in FA with AD and FA without AD under 12 months of age. The remission rates of milk allergy at 36 months of age were 64.9% and 90.0%, respectively, in FA with AD and FA without AD. In the egg allergy groups, initial egg-specific IgE levels were 34.48±36.72 kU(A)/L and 15.66±28.60 kU(A)/L, respectively, in FA with AD and FA without AD under 12 months of age. The remission rates of egg allergy at 36 months of age were 61.2% and 90.0% in children with FA with AD and FA without AD. CONCLUSION: Atopic dermatitis may play an important role in the natural history of food allergy in infants. Different strategies are needed for the management of food allergy in young children with atopic dermatitis.

Clinical characteristics and causative food types of immediate-type cow's milk and egg white allergy in children

PURPOSE: The aim of this study was to evaluate the details of the clinical characteristics and food exposure types at the first symptom onset in immediate-type cow's milk allergy (CMA) and egg white allergy (EWA) in Korean children. METHODS: This study included children with immediate-type CMA (n=288) or EWA (n=233) with symptom onset time of 2 hours or less, who visited Samsung Medical Center, Ajou University Hospital, and Soonchunhyang University Seoul Hospital between September 2014 and August 2015. The details of clinical features and food exposure types at the first symptom onset were evaluated by retrospective medical record review using a standardized case report form. RESULTS: The median ages of first symptom onset were 10 months in CMA and 12 months in EWA. The most common types of exposure at the first symptom in CMA were formula milk (29.5%) and milk (29.5%), followed by cheese (17.7%) and yogurt (14.2%). The most common type of exposure in EWA was boiled eggs (35.6%), followed by rice/porridge/soup containing eggs (27.5%), pan-fried eggs (17.6%), and baked goods (9.9%). Cutaneous symptoms were most common in both CMA and EWA, and anaphylaxis was noticed in 36.1% and 30.3%, respectively. Baked goods containing milk or eggs also induced anaphylaxis. The symptom onset time was less than 30 minutes in the majority of patients and the most common place of occurrence was home in both CMA and EWA. CONCLUSION: This study provides comprehensive information on CMA and EWA, and therefore helps clinicians diagnose and guide appropriate food restriction in children with CMA and EWA.

Safety of influenza vaccination in children with allergic diseases

Global guidelines strongly recommend annual influenza vaccination in people age 6 months and older, particularly in asthmatic children. There is no doubt about the benefit of influenza vaccination in asthmatic children. However, some of the vaccine's components may elicit an IgE mediated hypersensitivity or disease exacerbation, including life-threatening events, in children with allergic diseases. As a result, concerns regarding the safety of the vaccine still continue today. The influenza vaccine is grown on hens' eggs and contains a trace of egg protein. Consequently, it can provoke an allergic reaction or anaphylaxis in children with an egg allergy or exacerbation in those with asthma. Therefore, we need to know the risks and benefits of the influenza vaccine and the best strategy for safe vaccination. Although most guidelines have consistently reported the safety of influenza vaccination in children with allergic disease, and have recommended annual administration, safety concerns impede guideline-based performance in practice. The safety and efficacy of influenza vaccination for allergic children are summarized in the present review.

Diagnostic utility of skin prick test to cooked egg in children with egg allergy

PURPOSE: Reliable predictors of tolerance to cooked egg in an egg allergic population are not established. We investigated the usefulness of the skin prick test to cooked egg in children with egg allergy. METHODS: We studied 36 children with egg allergy. Skin prick tests (SPTs) for the uncooked or cooked form of egg white and egg yolk, whole egg, ovomucoid (OVM), and ovalbumin (OVA) were performed at diagnosis. The reagents of cooked egg for SPT were prepared by baking for 25 minutes in 200 degree oven. We also examined specific IgE levels to whole egg, egg white, egg yolk, OVM, and OVA. RESULTS: Patients with history of allergic reaction to extensively heated egg showed significantly increased wheal size for cooked egg white (median [interquartile range]), 10.5 [7.0-14.6] vs. 4.2 [0.0-5.6], P<0.001) and OVM (9.6 [7.3-13.8] vs. 5.6 [0.0-7.8], P=0.001) than those without the history. The strongest positive correlation was found between wheal size for cooked egg white and OVM (r=0.788, P<0.001). SPT wheal size for cooked egg white were positively correlated with serum OVM-specific IgE levels (r=0.691, P<0.001). Cutoff value was 7.0 mm in SPT wheal size for cooked egg white, the sensitivity was 73.1% and specificity was 99.0%. SPT for cooked egg white showed significantly higher area under curve than serum egg white specific IgE. CONCLUSION: Our results suggest that SPT to cooked egg white may be useful predictor of allergic reaction to cooked egg. Further investigations will be needed.

Alergia a la leche y al huevo: diagnóstico, manejo e implicaciones en América Latina / Milk and egg allergy: Diagnosis, management and implications for Latin America

La sensibilización a alimentos y el desarrollo de alergias alimentarias viene aumentando en todo el mundo, siendo la leche de vaca y el huevo de gallina los principales alimentos implicados. En la mayoría de los países latinoamericanos no existen guías de manejo y cuando se elaboren deberán adaptarse a las condiciones de la población de cada región. En el presente artículo presentamos una revisión del manejo de la alergia alimentaria a la leche y al huevo útil para el personal de salud de todos los niveles, así como algunas consideraciones de los factores presentes en los países latinoamericanos.

Sensitization to food allergens, as well as the development of food allergies, is increasing worldwide, and cow´s milk and hen´s eggs are the main implicated foods. In most Latin American countries there are no management guidelines on the aforementioned topics; at their creation, such guidelines should be adapted to the conditions of the population in each region. This paper presents a review of the management of food allergy to milk and eggs useful for health personnel at all levels and some considerations of the factors found in Latin American developing countries.

The Clinical Usefulness of IgE Antibodies Against Egg White and Its Components in Korean Children

PURPOSE: Egg (egg white) allergies are among the most common food allergies in infants and young children. Serum egg white-specific IgE (sIgE) levels have been shown to be correlated with clinical symptoms, and the predictive decision point of sIgE levels has been proposed and used widely in the clinical setting. However, some patients whose sIgE levels to egg white are higher than the predictive decision point value show no clinical symptoms, and vice versa. This study was conducted to evaluate the clinical usefulness of sIgE antibodies to egg white and its components in the diagnosis of egg allergies. METHODS: Forty-one patients younger than 2 years of age with no experience of egg intake due to concerns regarding allergies or a non-specific clinical response to eggs were enrolled. Total IgE levels and the levels of IgE antibodies specific for egg white and its components (ovomucoid, ovalbumin, and conalbumin) were measured by ImmunoCAP testing. The clinical response of the subjects was confirmed by an open oral food challenge (OFC). RESULTS: Fifteen (71.4%) out of 21 patients in the egg white-sIgE > or =2 kU/L group showed a positive response, while 10 (50.0%) out of 20 patients in the egg white-sIgE <2 kU/L group showed a negative response to the OFC. There were no statistically significant differences in the levels of sIgE antibodies against egg white and its components between the positive and negative open OFC groups. In addition, there were no statistically significant differences in the levels of sIgE antibodies against egg white and its components based on an intra-group analysis. CONCLUSIONS: Our results show that the sensitivity and specificity of the predictive decision point values for egg white-sIgE antibodies by ImmunoCAP were relatively low in Korean children. In addition, no egg white component predicted the clinical reactivity of the subjects. We suggest that the predictive decision point value for a positive egg oral challenge test by ImmunoCAP should be re-evaluated. Moreover, we suggest that careful personal history recording and challenge tests are necessary for the correct diagnosis of an egg allergy.

The safety of influenza vaccination in children with egg allergy

PURPOSE: Although influenza vaccine contains some residual egg protein (ovalbumin), recent studies have been reported that the influenza vaccine is even safe for patients with egg allergy. The object of this study was to assess the safety of influenza vaccination and estimate the risk factors of allergic reactions to influenza vaccination in children with egg allergy. METHODS: The medical records of 108 children were reviewed retrospectively, those were diagnosed as egg allergy at Department of Pediatrics in Severance Children's Hospital between January 2006 and December 2011. All of them were vaccinated with very low ovalbumin concentration (< or =0.12 microg/mL). Patients were vaccinated in graded doses by the international guideline. Subjects without allergic reactions to influenza vaccine among egg allergy patients were recruited as control subjects. RESULTS: Only 12 subjects of patients had adverse reactions to influenza vaccination. There were no significant relationships between adverse reactions to influenza vaccine and their own history of other allergy, history of breast feeding or graded vaccination. The egg allergy symptoms or egg-specific IgE levels were not associated with adverse reactions to influenza vaccination. CONCLUSION: These results show that patients with egg allergy may have adverse reactions with influenza vaccine, but severe adverse reactions are rare as general population. Therefore, the patients with egg allergy can be safe vaccinated with influenza vaccine, regardless of severity of allergic reaction after egg ingestion or methods of vaccination.

Atopy patch test (APT) in the diagnosis of food allergy in children with atopic dermatitis / Teste de contato atópico (TCA) no diagnóstico de alergia alimentar em crianças com dermatite atópica

BACKGROUND: Atopic Dermatitis is a chronic inflammatory skin disease. Food allergens are important in the pathogenesis in 1/3 of the cases. Several mechanisms are involved in the pathogenesis of Atopic Dermatitis. Immediate reactions are identified by both measurement of specific IgE and skin prick test. Atopy Patch Test seems to be relevant in the investigation of patients with suspected delayed-type reactions. OBJECTIVES: To evaluate the standardization of this method concerning allergen concentration, occlusion time and interpretation, and determine the specificity and sensitivity of the Atopy Patch Test according to the skin prick test and specific IgE levels in food allergy diagnosis in children with Atopic Dermatitis. METHODS: Seventy-two children, aged 2-12 years were selected and followed at the allergy clinic of the Hospital São Zacharias. Skin prick test, specific IgE and food Atopy Patch Test (cow's milk, egg, soy and wheat) were carried out. Three groups were submitted to the Atopy Patch Test: (1) Atopic Dermatitis with or without Rhinitis and Asthma; (2) Rhinitis and or Asthma without AD; (3) Healthy individuals. RESULTS: In group 1, 40% of the patients presented positive reactions. The longer the exposure time (48h and 72h), the higher the sensitivity. In group 2, the test was more specific than sensitive for all the extracts, with increased sensitivity the longer the time of exposure (72h). In group 3, 8.3% presented positive tests. CONCLUSION: APT evidenced a great diagnostic value in late-phase reactions to food, with high specificity. It showed to be a specific and reliable tool in comparison with the healthy group's results.

FUNDAMENTOS: A Dermatite Atópica é uma doença inflamatória crônica da pele. Os alimentos são importantes na patogênese da doença em 1/3 dos casos. Diversos mecanismos estão envolvidos na fisiopatogenia da dermatite Atópica. As reações imediatas são identificadas pela dosagem de IgE específica e teste de puntura. O teste de contato atópico parece ter relevância na investigação de pacientes com suspeita de reação tardia. OBJETIVOS: Avaliar a padronização do método com relação à concentração do alérgeno, tempo de oclusão e de interpretação; e determinar a especificidade e a sensibilidade do teste de contato atópico em relação ao teste de puntura e a dosagem de IgE específica, no diagnóstico de alergia alimentar em crianças com dermatite Atópica. MÉTODOS: Setenta e duas crianças com 2 a 12 anos foram submetidas a teste de puntura e dosagem de IgE específicas para alimentos (leite de vaca, ovo, soja, trigo). O teste de contato atópico foi aplicado em 3 grupos: (1) Dermatite Atópica com ou sem Rinite e Asma; (2) Rinite e ou Asma sem Dermatite Atópica; (3) Saudáveis. RESULTADOS: No grupo 1, 40% dos pacientes apresentaram reação positiva. Quanto maior o tempo de exposição, maior foi a sensibilidade. No grupo 2, o teste foi mais específico que sensível para todos os extratos; com aumento da sensibilidade com maior tempo de exposição (72h). No grupo 3, 8.3% apresentaram testes positivos. CONCLUSÃO: O teste de contato atópico mostrou ter valor diagnóstico em relação às reações de fase tardia a alimentos, com elevada especificidade. Mostrou-se um teste específico e confiável ao comparar com os resultados do grupo controle.

Application of atopy patch test in diagnosing egg and milk allergy among children with atopic dermatitis / 中华皮肤科杂志

Objective To evaluate the capacity of atopy patch test in diagnosis of food allergy in children with atopic dermatitis (AD).Methods Egg and milk,as the most common food allergens among Chinese children,were employed in this study.Skin prick test (SPT) and atopy patch test (APT) with fresh egg and milk were carried out in 68 children with AD.Oral food challenges in an open style were performed to confirm the diagnosis of food allergy.Resuits Of these patients,58(85.3%)were sensitive to egg,40(58.8%)to milk and 34(50.0%) to both.Of 98 patients with positive challenge,47 showed late response,10 immediate reactions.and 41 mixed reactions.The sensitivity,specificity,positive predictive value (PPV),negative predictive value (NPV) and the agreement with food challenges in diagnosis of egg/milk allergy were 96.6%/67.5%.90.0%/82.1%,98.2%/84.4%,81.8%/63.9% and 95.6%/73.5%,respectively for APT alone,37.9%/30.0%,100%/89.3%,100%/80.0%,21.7%/47.2% and 47.1%/54.4%,respectively for SPT alone.APT was found to be more sensitive in diagnosis of late-phase reactions than SPT (P<0.01).No significant difference was found in the sensitivity between APT alone and the combination of APT and SPT in parallel algorithm for diagnosis of egg or milk allergy (x2=0.509,0.549,both P>0.05) or in the specificity between APT alone and that in serial algorithm( P=1.000;x2=3.514,P>0.05).Conclusions APT is superior to SPT in diagnosis of late responses to food,and the combination of SPT and APT does not facilitate the diagnosis of food or milk allergy compared with APT alone.