Diagnosis and management of childhood food allergy

Ethical principles as a guide in implementing policies for the management of food allergies in schools

Food allergy in children is a growing public health problem that carries a significant risk of anaphylaxis such that schools and child care facilities have enacted emergency preparedness policies for anaphylaxis and methods to prevent the inadvertent consumption of allergens. However, studies indicate that many facilities are poorly prepared to handle the advent of anaphylaxis and policies for the prevention of allergen exposure are missing essential components. Furthermore, certain policies are inappropriate because they are blatantly discriminatory. This article aims to provide further guidance for school health officials involved in creating food allergy policies. By structuring policies around ethical principles of confidentiality and anonymity, fairness, avoiding stigmatization, and empowerment, policy makers gain another method to support better policy making. The main ethical principles discussed are adapted from key values in the bioethics and public health ethics literatures and will be framed within the specific context of food allergy policies for schools.

Familial auriculotemporal nerve (Frey) syndrome

Auriculotemporal nerve (Frey) syndrome in children is rare, and may be misdiagnosed as food allergy. Trauma to the auriculotemporal nerve during forceps-assisted delivery has been implicated in about half of the reported childhood Frey syndrome cases and most patients present with unilateral involvement. We describe two Caucasian sisters with bilateral Frey syndrome, neither of whom was delivered with forceps assistance, and highlight its distinction from food allergy. Frey syndrome may occur in a familial pattern, and in the absence of a history of perinatal trauma.

Food allergy knowledge, attitudes and beliefs: focus groups of parents, physicians and the general public

BACKGROUND

Food allergy prevalence is increasing in US children. Presently, the primary means of preventing potentially fatal reactions are avoidance of allergens, prompt recognition of food allergy reactions, and knowledge about food allergy reaction treatments. Focus groups were held as a preliminary step in the development of validated survey instruments to assess food allergy knowledge, attitudes, and beliefs of parents, physicians, and the general public.

METHODS

Eight focus groups were conducted between January and July of 2006 in the Chicago area with parents of children with food allergy (3 groups), physicians (3 groups), and the general public (2 groups). A constant comparative method was used to identify the emerging themes which were then grouped into key domains of food allergy knowledge, attitudes, and beliefs.

RESULTS

Parents of children with food allergy had solid fundamental knowledge but had concerns about primary care physicians' knowledge of food allergy, diagnostic approaches, and treatment practices. The considerable impact of children's food allergies on familial quality of life was articulated. Physicians had good basic knowledge of food allergy but differed in their approach to diagnosis and advice about starting solids and breastfeeding. The general public had wide variation in knowledge about food allergy with many misconceptions of key concepts related to prevalence, definition, and triggers of food allergy.

CONCLUSION

Appreciable food allergy knowledge gaps exist, especially among physicians and the general public. The quality of life for children with food allergy and their families is significantly affected.

Tolerance to extensively heated milk in children with cow's milk allergy

BACKGROUND

Cow's milk allergy is the most common childhood food allergy. Previously we noted that children who outgrew their milk allergy had milk-specific IgE antibodies primarily directed against conformational epitopes; those with persistent milk allergy also had IgE antibodies directed against specific sequential epitopes.

OBJECTIVE

Because high temperature largely destroys conformational epitopes, we hypothesized that some children with milk allergy would tolerate extensively heated (baked) milk products.

METHODS

Children with milk allergy were challenged with heated milk products; heated milk-tolerant subjects were subsequently challenged with unheated milk. Heated milk-tolerant, unheated milk-reactive subjects ingested heated milk products for 3 months and were then re-evaluated. Immune responses were assessed in all subjects; growth and intestinal permeability were followed in heated milk-tolerant subjects.

RESULTS

One hundred children (mean age, 7.5 years; range, 2.1-17.3 years) underwent heated milk challenges. Sixty-eight subjects tolerated extensively heated milk only, 23 reacted to heated milk, and 9 tolerated both heated and unheated milk. Heated milk-reactive subjects had significantly larger skin prick test wheals and higher milk-specific and casein-specific IgE levels than other groups. At 3 months, subjects ingesting heated milk products had significantly smaller skin prick test wheals and higher casein-IgG(4) compared with baseline; other immunologic parameters, growth, and intestinal permeability were not significantly different. Heated milk-reactive subjects had more severe symptoms during heated milk challenge than heated milk-tolerant subjects experienced during their unheated milk challenge.

CONCLUSION

The majority (75%) of children with milk allergy tolerate heated milk.

Rice protein-induced enterocolitis syndrome

BACKGROUND AND AIMS

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated allergic reaction, usually to cow's milk or soy protein. The aim is to present a series of infants with enterocolitis syndrome developed after rice ingestion. To our knowledge, the issue has only once been described in patients from Europe.

METHODS

Data on five patients were retrospectively analyzed. The patients presented with vomiting, diarrhea and dehydration; therefore, allergy was not considered as a diagnosis and the patients underwent broad diagnostic evaluation. Finally, an open food challenge was performed for suspicion of rice allergy.

RESULTS

Detailed clinical and laboratory findings are presented. As all patients had symptoms which could have been indicative of a broad spectrum of diseases, a median of two hospitalizations was needed to establish the diagnosis. When the rice protein-induced enterocolitis syndrome is suspected all patients should undergo open food challenge test, as no other diagnostic procedure can confirm the diagnosis.

CONCLUSION

This report shows that even hypoallergenic foods such as rice may cause FPIES and should be considered in the differential diagnosis of profuse vomiting and prostration in infants introduced to some kind of rice protein.

Role of probiotics in the management of patients with food allergy

OBJECTIVE

This review will concentrate on the potential use of probiotics in treating or preventing allergic disorders of the gastro-intestinal tract. In small infants, most reactions to foods are manifested in the gastro-intestinal tract. As children get older, cutaneous and even systemic or respiratory manifestations of food intolerances may be more common. In most instances, allergic disorders in the gut cause inflammation in the mucosa.

DATA SOURCES

Recently, the role of gut microflora in allergic disease has gained increasing interest with reports of probiotics being used to treat food allergy.

STUDY SELECTION

Pertinent scientific reports on the role of probiotics in the management of patients with food allergy will be reviewed. A recent study to determine the effect of very early probiotic colonization will be extensively reviewed as it presents an intriguing concept of a preventive strategy related to food allergy development

RESULTS

Significant improvement has been noted in infants receiving Lactobacillus GG in their extensively hydrolyzed formula.

CONCLUSIONS

It is likely more studies will be forthcoming with different probiotic organisms in the prevention and treatment of allergic disorders in children and adults.

An ELISA-based method for measurement of food-specific IgE antibody in mouse serum: an alternative to the passive cutaneous anaphylaxis assay

Passive cutaneous anaphylaxis (PCA) assay has been a gold standard method to measure allergen-specific IgE antibody (ASIgE Ab) levels in allergy mouse models. Many factors including stringent guidelines for laboratory animal use make PCA a difficult choice. Therefore, alternative methods are needed that can be readily applied for measurement of specific IgE antibody levels in mouse serum. Herein we describe a novel ELISA-based method that is more sensitive in comparison to PCA, IgE isotype-specific (because it has little cross-reactivity with IgG1 or IgG2a isotype) and highly reproducible (<10% inter- or intra-assay variation). Furthermore, we demonstrate the utility of this assay to measure specific IgE Ab against a variety of food extracts including chicken egg, peanut, almond, filbert/hazelnut and sweet potato. These findings are of particular interest to those who are seeking (i) to measure food-extract-specific IgE antibody in animal models and (ii) an alternative to the animal-based PCA method to measure mouse IgE antibodies.