The impact of oral food challenges for food allergy on quality of life: A systematic review

Background

Food allergy significantly impairs health‐related quality of life (HRQL). Currently, it is still unknown whether diagnostic interventions for food allergy improve HRQL. We aim to assess the impact of diagnostic interventions for food allergy on HRQL.

Methods

A systematic search was performed in MEDLINE, Embase, Cochrane Library, and CINAHL focused on patients with a (suspected) food allergy who underwent diagnostic interventions (ie, skin prick test, specific IgE, or oral food challenges [OFC]) and in whom HRQL was assessed. The mean difference between HRQL before and after the diagnostic intervention was calculated. A minimal clinically important difference of 0.5 was considered clinically relevant for the food allergy quality of life questionnaire.

Results

Seven of 1465 original identified publications were included in which the impact of an OFC on HRQL was investigated (total patients n = 1370). No other diagnostic interventions were investigated. Food allergy‐specific parent‐reported HRQL improved significantly after an OFC irrespective of the outcome in children with a suspected food allergy in two publications. The change was considered clinically relevant in one of two publications. In addition, parent‐reported HRQL improved after an OFC to assess the eliciting dose in children with a confirmed food allergy. The parental burden was significantly reduced after an OFC to assess resolution of food allergy. A meta‐analysis could not be performed due to the limited numbers of, and considerable heterogeneity between, eligible publications.

Conclusion

An OFC is associated with an improved food allergy‐specific HRQL and a reduced parental burden of food allergy.     

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??Abstract??Objective To investigate the diagnostic value of mean diameter of SPT in food allergic infants. Methods Totally 91 infants suspected with food allergy ??median age 7.35±2.94 months?? were selected??and all patients received family history inquiry??skin prick test and open food challenge.The mean diameter of SPT was measured??and OFC was performed to confirm food allergy.Diagnostic value of skin prick test, including the sensitivity and specificity, was calculated.In addition??receiver operating characteristic curve??ROC?? was plotted and area under the curve??AUC??was calculated to quantify the accuracy of the parameter.The SPSS software package version 13.0 for windows was used for all statistical analysis. Results A total of 128 babies received food challenge test?? in which there were 109 times of OFC positive and 19 times negative??totally 79 infants were diagnosed with FA.The induced symptoms of food challenge test included skin symptoms??70.6%??, gastrointestinal symptoms??20.2%??, rest with crying?? coughing?? rubbing eyes??etc.??9.2%??.When the rash MD was ≥3 mm??the sensitivity of SPT diagnosis milk??egg white and protein allergy was 19%??60.6% and 60.5% respectively??the area under ROC curve of rash MD in the milk??egg white??protein was 0.718??0.604 and 0.716 respectively?? the rates of three food SPT test results complying with the OFC were 44.4%??53.7% and 65.9%??the rates being 62.5%?? 58.3% and 31.3% in positive family history??when family history was negative??the area under the ROC curve of rash MD was 0.793. In the cases with positive family history??the area of ROC curve was 0.533.When rash MD of milk??egg white and protein was ≥2.2??5.0??4.7 mm or the rash MD was ≥3.25mm in children with a negative family history??SPT FA diagnostic specificity could be up to 100%. Conclusion SPT has some value in the diagnosis of FA. By finding the critical value of SPT FA and comprehensive analysis of family history??doctors can improve the diagnostic rate of FA. SPT can prevent some suspicious FA infants from food challenge test. It is very important to obtain rapid clinical diagnosis and to reduce the risk and burden to their families.     

Labial food challenge in children with food allergy

The current increase in the prevalence of food allergies appears to have several causes including better screening, improved diagnosis and changes in both the techniques used by food manufacturers and eating habits. Labial food challenge (LFC)is simple, rapid to perform and is associated with only low risks of systemic reaction. It is thus an appealing alternative to the oral food challenge (OFC) for pediatric use.
We report a series of 202 LFC performed over two years in 142 children with food allergy suspected from the case history, positive skin prick tests and specific serum IgE assays: 156 LFC were positive; and 46 negative, followed by positive single-blind, placebo-controlled food challenges (SB-PCFC). The foods provoking reactions were egg white (75 cases), peanut (60 cases), mustard (23 cases), cow's milk (13 cases), cod (8 cases), kiwi fruit, shrimp (4 cases each), chicken, peanut oil (3 cases each), hazel nuts (2 cases), and snails, apple, fennel, garlic, chilli peppers, pepper, and duck (1 case each). LFC positivity was mostly (89. 7% of cases) manifested as a labial edema with contiguous urticaria. There were systemic reactions in 4. 5% of cases: generalized urticaria, hoarseness and rapid-onset and generalized eczema. The 46 infants with negative LFC results had positive SBPCFC. The reactions were in 34 cases generalized urticaria, 10 cases asthma attacks, 2 cases early and generalized eczema, and in one case general anaphylactic shock. The sensitivity of the LFC was 77%. The LFC was easy to perform with children. Positive results indicate the presence of food allergy, but negative results require further investigations preferably double-blind, placebo-controlled food challenge (DBPCFC)     

The predictive value of skin prick testing for challenge-proven food allergy: a systematic review

Immunoglobulin E-mediated (IgE) food allergy affects 6-8% of children, and the prevalence is believed to be increasing. The gold standard of food allergy diagnosis is oral food challenges (OFCs); however, they are resource-consuming and potentially dangerous. Skin prick tests (SPTs) are able to detect the presence of allergen-specific IgE antibodies (sensitization), but they have low specificity for clinically significant food allergy. To reduce the need for OFCs, it has been suggested that children forgo an OFC if their SPT wheal size exceeds a cutoff that has a high predictability for food allergy. Although data for these studies are almost always gathered from high-risk populations, the 95% positive predictive values (PPVs) vary substantially between studies. SPT thresholds with a high probability of food allergy generated from these studies may not be generalizable to other populations, because of highly selective samples and variability in participant's age, test allergens, and food challenge protocol. Standardization of SPT devices and allergens, OFC protocols including standardized cessation criteria, and population-based samples would all help to improve generalizability of PPVs of SPTs.     

Follow‐up of patients with uncertain symptoms during an oral food challenge is useful for diagnosis

Background

Uncertain symptoms often emerge during an oral food challenge (OFC), and Open‐OFCs with those uncertain mild symptoms are ordinarily regarded as positive. Double‐blind placebo‐controlled food challenges should be conducted to determine these associations. Nevertheless, studies regarding the diagnosis of uncertain food allergy symptoms are lacking. We examined the diagnostic decision for a food allergy based on uncertain symptoms during an Open‐OFC.

Methods

We conducted an Open‐OFC between August 2005 and April 2012 with 2271 cases who suspected as allergic to hen's eggs, cow's milk, or wheat. For the primary diagnosis, Open‐OFCs with obvious symptoms were classified as “positive,” no symptoms as “negative,” and uncertain, indeterminate symptoms as “uncertain.” We encouraged the children in the uncertain group to consume the causative foods at home more than twice; if any definitive symptoms were induced, children were classified as “intolerant,” and children without any symptoms were classified as “tolerant,” for the final diagnosis.

Results

We analyzed 454 uncertain cases excluding 781 positive cases and 1036 negative cases. The symptoms that occurred for the uncertain cases included slight abdominal pain, localized skin rash, and an isolated cough. Of these cases, 362 (79.7%) were considered tolerant at the final diagnosis. Of the intolerant children at the final diagnosis, the induced symptoms at home were not serious.

Conclusions

Monitoring of recurring symptoms following consumption of causative foods at home by patients with uncertain symptoms improves the diagnostic accuracy of an Open‐OFC.     

Shellfish allergy in children

Food allergies affect approximately 3.5–4.0% of the world's population and can range from a mere inconvenience to a life-threatening condition. Over 90% of food allergies in childhood are caused by eight foods: cow's milk, hen's egg, soy, peanuts, tree nuts, wheat, fish, and shellfish. Shellfish allergy is known to be common and persistent in adults, and is an important cause of food induced anaphylaxis around the world for both children and adults. Most shellfish-allergic children have sensitivity to dust mite and cockroach allergens. Diagnostic cut-off levels for skin prick testing in children with shrimp allergy exist but there are no diagnostic serum-specific immunoglobulin E (IgE) values. All patients with symptoms of IgE-mediated reactions to shellfish should receive epinephrine autoinjectors, even if the initial symptoms are mild. In this study, we review three cases of clinical presentations of shellfish allergy in children.     

温州地区402例哮喘患儿特应质现象分析

目的 对温州地区15岁以下哮喘患儿特应质现象进行分析,探讨其临床及理论价值.方法 回顾性分析402例哮喘患儿皮肤过敏原诊断试验、血清特异性IgE、总IgE、个人过敏史、家族史、过敏原检出率、类型及与年龄关系.结果 哮喘发病有家族聚集倾向,家族过敏史总阳性率为52.74%.个人过敏史总阳性率为61.69%.过敏原皮肤诊断试验和过敏原血清特异IgE阳性率达83.58%,吸人性过敏原阳性人数占检测患儿的74.13%,其中以粉尘螨(61.44%)、屋尘螨(58.96%)为主;食人性过敏原阳性占24.38%,以小虾(16.67%)、牛奶(8.46%)为主.血清总IgE阳性率87.9%,总IgE阳性组和阴性组的哮喘患儿血清嗜酸性细胞阳离子蛋白(ECP)、户尘螨sIgE(D1)、粉尘螨sIgE(D2),皮肤过敏原诊断试验(pt)、家族过敏史、个人过敏史差异有统计学意义(P均≤0.05).哮喘患儿3岁前、后过敏原分布不同,3岁以后吸人性过敏原阳性为主.发病诱因中以上呼吸道感染为最多,哮喘症状发作的时间主要集中在临睡、夜晚、清晨.结论 儿童哮喘存在明显特应质现象,对其的正确认识和诊断对哮喘免疫机制的深入研究、综合治疗如在糖皮质激素吸入治疗的基础上,增加患儿教育、过敏原避免、特异性的免疫治疗等具有实用和理论指导意义.     

Natural history of IgE-mediated food allergy in fully breast-fed babies

We have studied 21 babies with IgE-mediated food allergy (FA) sensitized via breast milk. The diagnosis of IgE-mediated FA was based on the response to elimination diet and challenge tests, and was confirmed by positive RAST and skin tests. The children exhibited immediate symptoms, such as urticaria, angioedema, and asthma. Only 5/21 children developed tolerance to the offending food at the median age of 14 years. The children who failed to develop tolerance still have high levels of IgE antibodies towards the offending food. In conclusion, the results of our long-term follow-up study show that the natural history of FA in children sensitized via breast milk may be less optimistic than generally reported.     

Diagnosis of IgE‐mediated food allergy among Swiss children with atopic dermatitis

Diagnosis of food allergy in children with atopic dermatitis (AD) relies on a good knowledge of the prevalence of the disease and of the foods most frequently involved. Our objective was to define these characteristics in a population of Swiss children with AD. Patients referred to a pediatric allergist or a dermatologist for AD were routinely tested by skin‐prick test (SPT) to seven common food allergens (milk, egg, peanut, wheat, soy, fish, and nuts), and to all other foods suspected by history. Patients with positive SPTs were further evaluated for specific serum immunoglobulin E (IgE) antibodies (by using the CAP System FEIA^?). CAP values were interpreted following previously published predictive values for clinical reactivity. Patients with inconclusive results (between the 95% negative predictive value [NPV] and the 95% positive predictive value [PPV]) were challenged with the suspected food. A total of 74 children with AD were screened for food allergies. Negative SPTs excluded the diagnosis in 30 subjects. Nineteen patients were diagnosed by histories suggestive of recent anaphylactic reactions to foods and/or CAP values above the 95% PPV. Forty‐three food challenges (35 open challenges and eight double‐blind, placebo‐controlled in children with persistent lesions of AD despite aggressive topical skin treatment) were performed in patients with positive SPTs but with inconclusive CAP values. Six patients were diagnosed as positive to 15 foods. Challenges were not performed to high‐allergenic foods in young children (under 12 months of age for egg and fish, and under 3 years of age for peanuts and nuts). Altogether, 33.8% (25 of 74) of the AD patients were diagnosed with food allergy. The prevalence of food allergy was 27% (seven of 25) in the group referred to the dermatologist for primary care of AD. The foods most frequently incriminated were egg, milk, and peanuts. The prevalence of food allergy in our population was comparable to that in other westernized countries, suggesting an incidence of food allergy in approximately one‐third of children with persistent lesions of AD. Together with milk and eggs, peanuts were most frequently involved in allergic reactions.     

Tolerance of heat-treated kiwi by children with kiwifruit allergy

Kiwifruit allergy is increasing among children but whether heating affects clinical tolerance to kiwifruit is unknown. To assess tolerance to heated kiwifruit in children allergic to fresh kiwifruit. In this prospective trial, 20 children (median age 9.4 yr) with a history of immediate allergic reactions to fresh kiwifruit underwent double-blind placebo-controlled food challenges with steam-cooked (100 degrees C for 5') and industrially homogenised kiwifruit. Skin prick tests with a commercial kiwifruit allergen, raw kiwifruit and double-blind placebo-controlled food challenge with 25 g of fresh kiwifruit were used to confirm the history. Specific kiwifruit IgE to native and homogenized fruit were identified by immunoblotting. Fresh kiwifruit induced positive skin prick wheals in all children (confirmed during challenge in 19 patients). Commercial skin prick test elicited a positive response in five children, steam-cooked kiwifruit in five, and the homogenised kiwifruit preparation in none. UniCAP determinations were positive for kiwifruit in three patients. All children's sera showed specific IgE at immunoblotting with raw kiwifruit and one with the homogenised preparation (major allergens identified: Act c 1 and Act c 2). There was no clinical reactivity following challenge with homogenised kiwifruit but one child reacted to cooked kiwifruit challenge. Industrial heat treatment and homogenisation can make kiwifruit safe for children who are allergic to this increasingly popular fruit. This has dietary implications for children who are allergic to several fruit and vegetable proteins.     

Parents' estimate of food allergy prevalence and management in Italian school‐aged children

Background: Despite the increasing prevalence of food allergy, few studies have assessed the prevalence of perceived food‐induced symptoms among school‐aged children. There is also a paucity of data on how children with food reactions are managed. We investigated the frequency and characteristics of perceived food reactions in school‐aged children. Methods: Children aged 5–14 years were included in this cross‐sectional study. A standardized self‐administered questionnaire on food reactions was handed out to 900 parents. Results: We achieved a response rate of 69%. The lifetime prevalence of parental perceived allergic reactions to food was 10.5%; the point prevalence was 1.6%. Medical care included a call to a general practitioner in 54% of cases, self‐management in 37%, an emergency call in 6%, and hospitalization in 3%. Antihistamines were administered in 45% of food reactions, topical steroids in 24%, oral or parenteral steroids in 16%, and epinephrine in 1.5%. In children who reported food reactions, skin prick tests for foods were performed in 54% of cases; the oral food challenge test was performed in 7.5%. Conclusion: Parent perception of food allergic disorders is common in school‐aged children. Few children have undergone diagnostic tests to ascertain clinical food hypersensitivity. This is warranted to avoid unnecessarily restricted diets. Efforts should be made to train primary care physicians to manage food‐allergic children.     

Sensitization to food allergens in Iranian children with mild to moderate persistent asthma

Background

Asthma is the most common chronic respiratory disease in childhood. The clinical presentation of asthma may worsen after food allergen ingestion in sensitized patients. To avoid nonspecific dietary restrictions in children with asthma, laboratory-based advice about foods is potentially helpful. The purpose of this study was to determine food sensitization in children with asthma.

Methods

Seventy-nine children with mild to moderate persistent asthma were included in this study. Commercial food allergens including cow??s milk, egg white, almond, potato, and soybean were used in skin prick tests. Specific IgE to 20 common food allergens was also measured in serum.

Results

Twelve (15.2%) of the patients had a positive skin prick test to at least one of the five food extracts. Sensitization was detected by skin prick tests to cow??s milk and egg white (each 6.3%), almond (3.8%), potato (2.5%) and soybean (1.3%). Specific IgE levels ??0.35 kAU/L were detected in the serum of 47% of the children with asthma. The most common food allergens were cow??s milk (26.6%), hazelnuts (25.3%), wheat flour (15.2%) and egg white (12.6%). Patients with a history of at least one hospital admission due to asthma attack had a higher rate of sensitization to egg.

Conclusions

In our study, food sensitization was frequent in Iranian children with asthma. Although clinical food allergy could not be evaluated because food challenge tests were not used in our study, skin prick tests and serum-specific IgE to common food allergens might be helpful in identifying children with food sensitization.     

Frequency of food allergy in a pediatric population from Spain

We evaluated the prevalence and characteristics of the principal foods implicated in 355 children diagnosed with IgE-mediated food allergy. Diagnosis was established on the basis of positive clinical history for the offending food, positive specific IgE by skin prick test and RAST, and open food challenge. Our results showed the principal foods involved in allergic reactions are: eggs, fish, and cow's milk. These are followed in frequency by fruits (peaches, hazelnuts and walnuts), legumes (lentils, peanuts and chick peas) and other vegetables (mainly sunflower seeds). The legumes demonstrated the highest degree of clinical cross-reactivity. Most patients with food allergy reacted to one or two foods (86.7%). Only 13.3% of patients reacted to 3 or more foods, mostly to legumes and fruits. We found that food allergy begins most frequently in the first (48.8%) and second (20.4%) years of life. Allergy to proteins of cow's milk, egg, and fish begins predominantly before the second year, demonstrating a clear relationship with the introduction of these foods into the child's diet. Allergy to foods of vegetable origin (fruits, legumes and other vegetables) begins predominantly after the second year.;     

The prevalence of food hypersensitivity in an unselected population of children and adults

A rising prevalence of food hypersensitivity (FHS) and severe allergic reactions to food has been reported the last decade. To estimate the prevalence of FHS to the most common allergenic foods in an unselected population of children and adults. We investigated a cohort of 111 children <3 yr of age, 486 children 3 yr of age, 301 children older than 3 yr of age and 936 adults by questionnaire, skin prick test, histamine release test and specific immunoglobulin E followed by oral challenge to the most common allergenic foods. In total, 698 cases of possible FHS were recorded in 304 (16.6%) participants. The prevalence of FHS confirmed by oral challenge was 2.3% in the children 3 yr of age, 1% in children older than 3 yr of age and 3.2% in adults. The most common allergenic foods were hen's egg affecting 1.6% of the children 3 yr of age and peanut in 0.4% of the adults. Of the adults, 0.2% was allergic to codfish and 0.3% to shrimp, whereas no challenges with codfish and shrimp were positive in the children. The prevalence of clinical reactions to pollen-related foods in pollen-sensitized adults was estimated to 32%. This study demonstrates the prevalence of FHS confirmed by oral challenge to the most common allergenic foods in an unselected population of children and adults.     

Non‐IgE‐mediated gastrointestinal food allergies in children

Non‐IgE‐mediated gastrointestinal food allergic disorders (non‐IgE‐GI‐FA) including food protein‐induced enterocolitis syndrome (FPIES), food protein‐induced enteropathy (FPE), and food protein‐induced allergic proctocolitis (FPIAP) are relatively uncommon in infants and young children, but are likely under‐diagnosed. Non‐IgE‐GI‐FA have a favorable prognosis, with majority resolving by age 3–5 years. Diagnosis relies on the recognition of symptoms pattern in FPIAP and FPIES and biopsy in FPE. Further studies are needed for a better understanding of the pathomechanism, which will lead eventually to the development of diagnostic tests and treatments. Limited evidence supports the role of food allergens in subsets of constipation, gastroesophageal reflux disease, irritable bowel syndrome, and colic. The immunologic pathomechanism is not fully understood and empiric prolonged avoidance of food allergens should be limited to minimize nutrient deficiency and feeding disorders/food aversions in infants.     

The association between early sensitization patterns and subsequent allergic disease. The DARC birth cohort study

Prevention of allergic diseases depends on early identification of clinical markers preceding such disorders. This study describes the natural course of sensitization as measured by skin prick test (SPT) and specific immunoglobulin E (S‐IgE) and analyses the association between early sensitization patterns and subsequent allergic disease at 6 yr of age. In an ongoing population‐based birth cohort study of 562 children, follow‐up visits were performed at 0, 3, 6, 9, 12, 18, 36, and 72 months. Visits included an interview, physical examination, SPTs, and S‐IgE measurements for 12 food and inhalant allergens. The frequency of S‐IgE sensitization to ≥1 inhalant allergen was constant from 0 to 6 months (9–10%), decreased at 12–18 months before increasing from 36 months onwards. S‐IgE sensitization to at least one food allergen remained constant from 0 to 6 yr. SPT sensitization to food and inhalant allergens appeared from 3 and 12 months, respectively. Early food sensitization (S‐IgE) between 3 and 18 months was found to be significantly (p < 0.05) associated with atopic dermatitis (OR: 4.0 [1.6–9.9]) and asthma (OR 4.0 [1.1–12.5]) at the age of 6 yr. Children with atopic dermatitis, asthma, or rhinoconjunctivitis, and sensitization at 6 yr, were sensitized to food allergens to a large extent (53%, 42%, and 47%, respectively) already at 6 months. Early inhalant sensitization (S‐IgE) did not increase the risk of later allergic disease. Early atopic dermatitis (0–18 months) was also highly associated with subsequent allergic disease. Children with early food sensitization and/or atopic dermatitis would be a proper target group for future interventional studies.     

Identification of the etiologies of chronic urticaria in children: A prospective study of 94 patients

Jirapongsananuruk O, Pongpreuksa S, Sangacharoenkit P, Visitsunthorn N, Vichyanond P. Identification of the etiologies of chronic urticaria in children: A prospective study of 94 patients.
Pediatr Allergy Immunol 2010: 21: 508–514.
© 2009 John Wiley & Sons A/S The etiologies of chronic urticaria (CU) in childhood remains incompletely understood because of limited data in children. The objective of this study was to examine some of the possible etiologies of CU in children by focusing on the functional autoantibody to FcεRIα and IgE, thyroid autoimmunity, urticarial vasculitis, parasitic infestation and food allergy. Children 4–15 yr of age with CU were investigated for complete blood count, erythrocyte sedimentation rate (ESR), antinuclear antibody (ANA), CH₅₀, free‐T4 (FT₄), thyroid stimulating hormone (TSH), anti‐thyroglobulin and anti‐microsomal antibody, autologous serum skin test (ASST), skin prick tests (SPT) for foods, food challenges, and stool examination for parasites. Ninety‐four children who met the criteria for CU were recruited. Patients with physical urticaria were excluded. Eosinophilia and elevated ESR were found in 23% and 13%, respectively. High ANA titers were found in 2%. None of these patients had clinical features of urticarial vasculitis, abnormal CH₅₀ level, abnormal TSH and FT₄. Anti‐thyroglobulin and anti‐microsomal antibodies were not detected. Positive ASST was found in 38%. There were no differences in medication requirement and CU remission between patients with positive and negative ASST. Parasites were found in 5% without clinical correlation. SPT to foods was positive in 35%. Positive food challenges were found in six/nine patients with positive history of food allergy and two/seven patients with negative history. Food avoidance was beneficial to the subgroup of patients with positive history of food allergy only.     

Predictive factors for the persistence of cow’s milk allergy

Santos A, Dias A, Pinheiro JA. Predictive factors for the persistence of cow’s milk allergy.
Pediatr Allergy Immunol 2010: 21: 1127–1134.
© 2010 John Wiley & Sons A/S Cow’s milk allergy (CMA) is usually transient, but recent studies have shown a later acquisition of tolerance to CM. Our aims were to characterize a population of Portuguese children with CMA and to identify predictive factors for the persistence of this food allergy. Children with CMA observed in our Paediatric Allergy Clinic between 1997 and 2006 were selected. Demographic and clinical data were collected from medical records. The group of children who tolerated CM before the age of 2 was compared with the group of children who tolerated CM beyond that age or persisted with CMA until the end of the study. Multivariate logistic regression analysis was used to investigate independent predictive factors for the persistence of CMA beyond the age of 2. In the subgroup of children with IgE‐mediated CMA, the acquisition of tolerance was analysed using Cox regression. In this population of 139 children, the majority presented more than one symptom (73%) affecting more than one organ (51%), with cutaneous (81%), gastrointestinal (55%), respiratory (16%) manifestations and/or anaphylaxis (3%). Thirty‐two per cent developed asthma, 20% atopic eczema, 20% rhinoconjunctivitis and 19% other food allergies over time. The acquisition of tolerance was different in the whole population versus the subgroup with IgE‐mediated CMA: 34%versus 0% at the age of 2, 55%versus 22% at the age of 5 and 68%versus 43% at the age of 10. Immediate allergic symptoms, asthma and other food allergies were independent factors for the persistence of CMA beyond the age of 2. Higher maximum weal diameter on skin prick test to CM and higher maximum level of specific IgE to CM were associated with reduced likelihood of acquiring tolerance in the subgroup of children with IgE‐mediated CMA. In conclusion, children with IgE‐mediated CMA acquire tolerance to CM at older age. Clinical parameters and allergy tests may be helpful in defining prognosis. CM‐allergic children tend to develop other atopic conditions and need specialized follow‐up in the long term.     

喘息性疾病患儿过敏原检测分析

目的分析喘息性疾病婴幼儿过敏情况,以利早期干预治疗。方法用UniCAP全自动检测仪和皮肤点刺试验对243例喘息性疾病婴幼儿(毛细支气管炎、伴喘息的支气管炎或肺炎、婴幼儿哮喘)进行过敏原筛查和特异性IgE测定。结果1.婴儿期过敏原以食物为主(P=0.03),幼儿期气媒性过敏原阳性率达67.2%;婴幼儿期主要的食物过敏原为牛奶、鸡蛋白;气媒性过敏原是户尘螨。2.进行过敏原特异性IgE测定时,皮肤点刺试验阳性比例低(0～37.5%)。结论婴儿出生后即食入蛋白质,胃肠道功能未健全,易发生食物过敏;幼儿期添加易致敏食物,且在户外时间增多,食物和吸入性过敏均明显。UniCAP系统是一种用于筛查和寻找变应原的较为准确的方法。     

Food allergy and atopic dermatitis in infancy: an epidemiologic study

Atopic dermatitis is common in infancy. The role of food allergy in atopic dermatitis of infancy is unclear. We examined the relationship between atopic dermatitis and immunoglobulin E (IgE)-mediated food allergy in infancy. A birth cohort of 620 infants with a family history of eczema, asthma, hayfever or immediate food allergy in a parent or sibling: 487 children had complete data including skin prick tests (SPTs) to evaluate IgE-mediated food allergy to cow milk, egg and peanut. Participants were grouped as no atopic dermatitis (Gp 0) or in quartiles of increasing severity of atopic dermatitis (Gps 1-4) quantified by days of topical steroid use as reported monthly. Adverse reactions to foods were recorded. The cumulative prevalence of atopic dermatitis was 28.9% to 12 months (10.3% of the cohort of moderate severity). As atopic dermatitis severity increased so did the prevalence of IgE-mediated food allergy (Gp 0, 40/346 vs. Gp 1, 6/36 vs. Gp 2, 8/35 vs. Gp 3, 12/35 vs. Gp 4, 24/35; chi(2) = 76; p < 10(-6)), and the frequency of reported adverse food allergy reactions (Gp 0, 43/346 vs. Gp 1, 4/36 vs. Gp 2, 8/35, vs. Gp 3, 5/35, vs. Gp 4, 13/35; chi(2) = 17; p = 0.002). The relative risk of an infant with atopic dermatitis having IgE-mediated food allergy is 5.9 for the most severely affected group. Atopic dermatitis is common in infancy. There is a strong association between IgE-mediated food allergy and atopic dermatitis in this age group.