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)     

Intolerance to food additives – does it exist?

'Food intolerance' is often confused with a range of adverse symptoms which may be coincidental to ingestion of food. 'Food intolerance' is defined as a reaction in which symptoms must be objectively reproducible and not known to involve an immunological mechanism. A more precise term is non-allergic food hypersensitivity, which contrasts with food allergies which are due to an immunological mechanism. Some children will experience food reactions to food additives. Reported symptoms range from urticaria/angioedema to hyperactive behaviours. While parents/carers report that over one fifth of children experience of food reaction, only 1 in 20 of these are confirmed to have a non-allergic food hypersensitivity on testing.     

Food composition: antigens

Relatively few food antigens have been purified to homogeneity and completely characterized. These include Gad c I from codfish; Sin a I from mustard seed; casein and beta-lactoglobulin from cow's milk; and ovalbumin, ovomucoid, and conalbumin from eggs. Multiple allergens are present in crustaceans, legumes, and cereal grains. Most vegetable seed allergens are proteins; refined oils from these seeds (peanut, soybean, sunflower) contain no nitrogen and are thus non-allergenic. Many food allergens are shared with pollens, so that pollen-sensitive persons may exhibit itching of the tongue and palate when the cross-reacting food is ingested.     

A survey of patients with self-reported severe food allergies in Japan

Food allergies have increased in recent years in Japan. Details of causative foods, places where anaphylaxis developed, and other allergic factors remain unknown, and we investigated them. A'questionnaire survey for the prevention of food allergies' was conducted using a nationwide group of patients with food allergies. A total of 1383 patients from 878 families (including 319 patients who experienced anaphylaxis) provided valid answers to the questionnaire. The average age of the first anaphylactic attack was 3.20 ± 6.327 yr. The most common allergens causing anaphylaxis were in order milk, eggs, wheat, peanuts, and soybeans, followed by sesame and buckwheat. The most common place where anaphylaxis developed was the patient's own home, followed by fast food restaurants, places visited, restaurants, and schools. In patients' own homes, fast food restaurants (buffet), places visited and schools, the most common allergens were milk, eggs, and wheat. In restaurants and accommodation facilities, eggs were the most common allergen followed by milk. As possible food allergies can cause anaphylaxis, it is necessary to provide precise information for consumers regarding packaged and processed foods.     

Application of an electrophoretic methodology for the identification of low molecular weight proteins in foods

Identification and characterisation of food proteins are core features of food allergy research. Current methods used to identify allergenic proteins in food have insufficient resolution and are unable to delect low molecular weight proteins. In this study we report the use of a simple SDS-PAGE method which allows resolution of small proteins. We have subsequently applied this method and reported presence of low molecular weight proteins in a range of hydrolysed milk formulae (Nutramigen, Pregistimil, Alfare, Pepti-Junior and Pregomin), and crude peanut protein extract. The molecular weight distribution for the peanut extract and the hydrolysates ranged between 5-200kDa and 2-17kDa respectively.     

Factors associated with maternal dietary intake,feeding and weaning practices,and the development of food hypersensitivity in the infant

Maternal diet during pregnancy and breastfeeding, as well as infant feeding and weaning practices, may play a role in the development of sensitization to food and food hypersensitivity (FHS) and need further investigation. Pregnant women were recruited at 12 wk pregnancy. Information regarding family history of allergy was obtained by means of a questionnaire. A food frequency questionnaire was completed at 36 wk gestation. Information regarding feeding practices and reported symptoms of atopy was obtained during the infants’ first 3 yr of life. Children were also skin‐prick tested at 1, 2 and 3 yr to a pre‐defined panel of food allergens. Food challenges were conducted where possible. Maternal dietary intake during pregnancy, and breast‐feeding duration did not influence the development of sensitization to food allergens or FHS, but weaning age (≥16 wk) did for sensitization at 1 yr (p = 0.03), FHS by 1 yr (p = 0.02), sensitization at 3 yr (p = 0.01) and FHS by 3 yr (p = 0.02). In contrast, children who were not exposed to a certain food allergen before the age of 3–6 months were less likely to become sensitized or develop FHS. Women with a family history of allergic disease were more likely to breastfeed exclusively at 3 months (p = 0.008) and avoid peanuts from the infant’s diet at 6 months (p = 0.03). Maternal dietary intake during pregnancy, and breast‐feeding duration did not appear to influence the development of sensitization to food allergens or FHS. Weaning age may affect sensitization to foods and development of FHS. A history of allergic disease has very little impact on maternal dietary, feeding, and weaning practices.     

Food allergy: When and how to perform oral food challenges

In many situations, the diagnosis of food allergy rests simply upon a history of an acute onset of typical symptoms, such as hives and wheezing, following the isolated ingestion of a suspected food, with confirmatory laboratory studies of positive prick skin tests or RASTs. However, the diagnosis is more complicated when multiple foods are implicated or when chronic diseases, such as asthma or atopic dermatitis, are evaluated. The diagnosis of food allergy and identification of the particular foods responsible is also more difficult when reactions are not mediated by IgE antibody, as is the case with a number of gastrointestinal food allergies. In these latter circumstances, well‐devised elimination diets followed by physician‐supervised oral food challenges are critical in the identification and proper treatment of these disorders. Since childhood food allergies to common allergenic foods such as milk, egg, wheat and soy are usually outgrown, oral food challenges are also an integral part of the long‐term management of these children.     

Parental awareness and attitudes of food marketing to children: A community attitudes survey of parents in New South Wales, Australia

Aim:   To determine parents' attitudes and awareness of food marketing to children.
Method:   Computer-assisted telephone interviews of a random sample of 400 parents of children aged 5–17 years and who were the main grocery buyers for that household, living in NSW, Australia. The main outcome measures included parental awareness and attitudes relating to food marketing to children, the perceived role of government versus industry in food marketing regulation and children's food purchasing requests as a result of exposure to food marketing.
Results:   The majority of parents were concerned about food marketing to children, with the highest level of concern registered for the positioning of food at supermarket checkouts (83% of parents concerned). Parental awareness of certain non-broadcast media food marketing (e.g. print, radio and premium offers) to children was low. The majority of parents (91%) did not trust the industry to protect children from food marketing. Most parents (81%) believed that the government should restrict the use of non-broadcast media marketing of unhealthy food to children. Parents of younger children were more likely to report that their child asked for advertised food products, compared with parents of adolescents (65% and 48% respectively, P < 0.0001).
Conclusions:   Reductions in point of sale food promotions would be welcomed by parents. Raising community awareness of the non-broadcast media channels used to market food to children is important as part of building family and policy efforts to limit exposure to this otherwise relatively unregulated media environment.     

食物蛋白诱导的儿童过敏性直肠结肠炎研究进展

回顾总结食物蛋白诱导的儿童过敏性直肠结肠炎的流行病学、致病机制、临床表现、辅助检查、诊断及管理的最新进展。食物蛋白诱导的儿童过敏性直肠结肠炎主要是由非IgE介导的免疫反应,致病机制复杂,与多种因素有关,其症状可表现为哭闹、腹泻、便血、皮疹等,可累及消化、呼吸、皮肤等一个或多个系统。回避饮食有效加上激发试验阳性为诊断的金标准,饮食回避是治疗食物蛋白诱导的儿童过敏性直肠结肠炎的主要方法,全面认识并掌握其临床特点,早期诊治,合理实施营养,预后良好。     

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.     

Atopy patch test for the diagnosis of food protein-induced enterocolitis syndrome

Food protein-induced enterocolitis syndrome (FPIES) is thought to be a non-IgE mediated food allergy syndrome. Affected infants typically demonstrate gastrointestinal symptoms after hours after ingestion of the offending food. Traditional allergy testing is not useful for this disorder because tests for food specific IgE are routinely negative. A diagnostic oral food challenge (OFC) is the only method to confirm the diagnosis of FPIES. This prospective study was undertaken to determine whether the atopy patch test (APT) is able to predict the results of the OFC. Nineteen infants with suspected FPIES by clinical history underwent APT to the suspected foods. After APT was performed, subjects underwent OFC to determine whether FPIES was present. The results of APT and OFC were compared and used to calculate sensitivity and specificity of the APT. APT predicted the results of oral food challenges in 28/33 instances. There were 16 cases of FPIES confirmed by oral food challenges. In all 16 cases of FPIES, the APT was positive to the suspected food. However, the APT was positive in five instances where the oral food challenge was negative. All 12 patients with a negative APT had a negative oral food challenge to the suspected food. APT appears to be a promising diagnostic tool for the diagnosis of FPIES.     

Early introduction of complementary foods/drinks and milk feeding type in the Special Supplemental Nutrition Program for Women,Infants and Children (WIC)

Infants younger than 4 months are not ready for complementary foods/drinks (any solid or liquid other than breast milk or infant formula). Almost half of US infants participate in the Special Supplemental Nutrition Program for Women, Infants and Children (WIC), which provides nutrition education and support to low-income families. We describe the prevalence of early introduction (<4 months) of complementary foods/drinks and examine the association of milk feeding type (fully breastfed, partially breastfed or fully formula fed) with early introduction of complementary foods/drinks. We used data from 3310 families in the longitudinal WIC Infant and Toddler Feeding Practices Study-2. We described the prevalence of early introduction of complementary foods/drinks and modeled the association of milk feeding type at Month 1 with early introduction of complementary foods/drinks using multi-variable logistic regression. Thirty-eight percent of infants were introduced early to complementary foods/drinks (<4 months). In adjusted models, infants who were fully formula fed or partially breastfed at Month 1 were 75% and 57%, respectively, more likely to be introduced early to complementary foods/drinks compared with fully breastfed infants. Almost two in five infants were given complementary foods/drinks early. Formula feeding at Month 1 was associated with higher odds of early introduction of complementary foods/drinks. There are opportunities to support families participating in WIC to prevent early introduction of complementary foods/drinks and promote child health.     

Early introduction of allergenic foods for the prevention of food allergy from an Asian perspective—An Asia Pacific Association of Pediatric Allergy,Respirology & Immunology (APAPARI) consensus statement

Emerging evidence for the early introduction of allergenic foods for the prevention of food allergies, such as peanut allergy in Western populations, has led to the recent publication of guidelines in the USA and Europe recommending early peanut introduction for high‐risk infants with severe eczema or egg allergy. Peanut allergy is, however, much less prevalent in Asia compared to the West. Varying patterns of food allergy are seen even within Asian countries—such as a predominance of wheat allergy in Japan and Thailand and shellfish allergy in Singapore and the Philippines. Customs and traditions, such as diet and infant feeding practices, also differ between Asian populations. Hence, there are unique challenges in adapting guidelines on early allergenic food introduction to the Asian setting. In this paper, we review the evidence and discuss the possible approaches to guide the timely introduction of allergenic food in high‐risk infants in Asia.