Food protein-induced enterocolitis syndrome: laboratory perspectives

Early infancy dysbiosis in food protein-induced enterocolitis syndrome: A prospective cohort study

BACKGROUND

The microbiome associations of food protein-induced enterocolitis syndrome (FPIES) are understudied. We sought to prospectively define the clinical features of FPIES in a birth cohort, and investigate for the evidence of gut dysbiosis.

METHODS

We identified children diagnosed with FPIES in the Gastrointestinal Microbiome and Allergic Proctocolitis Study, a healthy infant cohort. Children were assessed and stools were collected at each well child visit. The clinical features of the children with FPIES were summarized. Stool microbiome was analyzed using 16S rRNA sequencing comparing children with and without FPIES.

RESULTS

Of the 874 children followed up for 3 years, 8 FPIES cases (4 male) were identified, yielding a cumulative incidence of 0.92%. The most common triggers were oat and rice (n = 3, each) followed by milk (n = 2). The children with FPIES were more likely to have family history of food allergy (50% vs. 15.9% among unaffected, p = .03). The average age of disease presentation was 6 months old. During the first 6 months of life, stool from children with FPIES contained significantly less Bifidobacterium adolescentis, but more pathobionts, including Bacteroides spp. (especially Bacteroides fragilis), Holdemania spp., Lachnobacterium spp., and Acinetobacter lwoffii. The short-chain fatty acid (SCFA)-producing Bifidobacterium shunt was expressed significantly less in the stool from FPIES children.

CONCLUSIONS

In this cohort, the cumulative incidence over the 3-year study period was 0.92%. During the first 6 months of life, children with FPIES had evidence of dysbiosis and SCFA production pathway was expressed less in their stool, which may play an important role in the pathogenesis of FPIES.

Allergic Proctocolitis Is a Risk Factor for Functional Gastrointestinal Disorders in Children

OBJECTIVE

To test the hypothesis that allergic proctocolitis, a cause of self-limiting rectal bleeding in infants, can predispose to the development of functional gastrointestinal disorders (FGIDs) later in childhood.

STUDY DESIGN

We studied a cohort of 80 consecutive patients diagnosed with allergic proctocolitis. Their sibling or matched children presenting to the same hospital for minor trauma served as controls. Parents of the patients with allergic proctocolitis and controls participated in a telephone interview every 12 months until the child was at least 4 years old. At that time, they were asked to complete the parental Questionnaire on Pediatric Gastrointestinal Symptoms, Rome III version.

RESULTS

Sixteen of the 160 subjects (10.0%) included in the study met the Rome III criteria for FGIDs. Among the 80 patients with allergic proctocolitis, 12 (15.0%) reported FGIDs, compared with 4 of 80 (5.0%) controls (P = .035). After adjustment for age and sex, the OR for FGIDs in allergic proctocolitis group was 4.39 (95% CI, 1.03-18.68). FGIDs were significantly associated with iron deficiency anemia, duration of hematochezia, and younger age at presentation. In a multivariate analysis, only the duration of hematochezia was significantly associated with the development of FGIDs (OR, 3.14; 95% CI,1.72-5.74).

CONCLUSIONS

We have identified allergic proctocolitis as a new risk factor for the development of FGIDs in children. Our data suggest that not only infection, but also a transient early-life allergic inflammatory trigger may induce persistent digestive symptoms, supporting the existence of "postinflammatory" FGIDs.

Short article: The endoscopic and histologic findings of infants who have experienced brief resolved unexplained events

INTRODUCTION

A brief resolved unexplained event (BRUE) describes an event associated with a change in muscle tone, color, respiration, and responsiveness that is unexplained after an appropriate examination. Some infants with higher risk BRUE may undergo endoscopy as part of their evaluation.

OBJECTIVE

This retrospective study aimed to identify the endoscopic findings in infants who have experienced a higher risk BRUE. We also compared the characteristics, prenatal, natal, and postnatal risk factors between 23 infants who underwent endoscopic evaluation and 23 race-matched/sex-matched/term-matched/preterm-matched infants who did not undergo endoscopic evaluation.

METHODS

This was a retrospective descriptive study. Infants were identified from a query of medical records using the ICD-10 code for BRUE (R68.13).

RESULTS

Of 119 infants with BRUE, 23 infants with higher risk BRUE underwent an esophagogastroduodenoscopy and flexible sigmoidoscopy. Apnea (87%) was the most common presentation of BRUE. Most were female (57%) with a mean age at BRUE presentation of 2.73 months. We found 10 (43.5%) term infants and 13 (56.5%) preterm infants in our study. There were no significant differences in characteristics, prenatal, natal, and postnatal risk factors between the infants who underwent endoscopy and those who did not undergo endoscopy. The most common abnormal endoscopic finding was lymphonodular hyperplasia (LNH) associated with eosinophilia in the rectosigmoid colon. The proportion of females in the LNH group was significantly higher than the non-LNH group.

CONCLUSION

Rectosigmoid LNH and eosinophilia, which are associated with milk soy protein intolerance (MSPI), were the most common findings on endoscopic evaluation. Although there is no proof of causation between MSPI and BRUE, MSPI should be considered in the differential diagnosis for higher risk BRUE.

Levels of inflammatory cytokines from peripheral blood mononuclear cells of children with cow's milk protein allergy

Aim

The aim of the study was to investigate the level of cytokines in cultures of cow's milk protein- stimulated peripheral blood mononuclear cells of patients with cow's milk protein allergy.

Material and Methods

Eleven children with cow's milk protein allergy and 11 non-allergic controls were studied. Their peripheral blood mononuclear cells were cultured alone and in the presence of cow's milk α-lactalbumin; β-lactoglobulin; αS 1, αS 2, β, and κ-casein fraction mixtures; and a cow's protein mixture from whole milk. Production of cytokines, tumor necrosis factor-α, interleukin-10, and interleukin-12 were determined in culture supernatants.

Results

In cow's milk protein-stimulated peripheral blood mononuclear cell cultures of children with cow's milk protein allergy, tumor necrosis factor-α, interleukin-10, and interleukin-12 production was significantly higher than in non-allergic controls (p<0.05). No difference in cytokine production was found between cultures obtained from unstimulated peripheral blood mononuclear cell cultures of both cow's milk protein allergy and non-allergic controls.

Conclusions

The findings of this preliminary study align with data from the literature suggesting that the investigation of tumor necrosis factor-α, interleukin-10, and interleukin-12 in cow's milk protein-stimulated peripheral blood mononuclear cell cultures of children may be taken in further consideration to explore whether they might have a predictive role for cow's milk protein allergy. Further studies are therefore needed to extensively investigate this issue.

Comparative evaluation of cow β-casein variants (A1/A2) consumption on Th2-mediated inflammatory response in mouse gut

PURPOSE

Recently, apprehension has been raised regarding "A1/A2 hypothesis" suggesting relationship between consumption of A1 "like" variants of cow β-casein and various physiological disorders. The information available is based on either the human epidemiological data of milk consumption or in vitro trials on cell lines with β-casomorphin peptides. The direct scientific evidence establishing the link between consumption of A1/A2 "like" milk and health is scanty. Thus, under present investigation, in vivo trials in mice were undertaken to study the effect of feeding three genetic variants (A1A1, A1A2 and A2A2) of cow β-casein milk on gastrointestinal immune system as it is the first and foremost site of immunological interactions.

METHODS

Animals were divided into four groups for feeding with basal diet (control) and β-casein isolated from milk of genotyped (A1A1, A1A2 and A2A2) dairy animals, respectively. Gut immune response was analyzed by spectrophotometric assessment of MPO activity, quantitative sandwich ELISA of inflammatory cytokines (MCP-1 and IL-4), antibodies (total IgE, IgG, sIgA, IgG1 and IgG2a) and qRT-PCR of mRNA expression for toll-like receptors (TLR-2 and TLR-4). Histological enumeration of goblet cells, total leukocytes and IgA(+) cells was also carried out.

RESULTS

It was observed that consumption of A1 "like" variants (A1A1 and A1A2) significantly increased (p < 0.01) the levels of MPO, MCP-1, IL-4, total IgE, IgG, IgG1, IgG2a and leukocyte infiltration in intestine. TLR-2 and TLR-4 mRNA expression was also up-regulated (p < 0.01) on administration of A1 "like" variants. However, no changes in sIgA, IgA(+) and goblet cell numbers were recorded on consumption of any of the β-casein variants.

CONCLUSION

It is reasonable to conclude that consumption of A1 "like" variants of β-casein induced inflammatory response in gut by activating Th2 pathway as compared to A2A2 variants. The present study thus supports the purported deleterious impacts of consumption of A1 "like" variants of β-casein and suggests possible aggravation of inflammatory response for etiology of various health disorders.

Effect of thermal processing of cow and buffalo milk on the allergenic response to caseins and whey proteins in mice

BACKGROUND

Heat treatment is the most common method for reducing pathogen load, but it remains controversial in reducing the incidence of hyperimmune reactions. The aim of this study was to compare the allergenicity of caseins (CSN) and whey proteins (WP) of thermally processed cow and buffalo milk in a mouse model. Swiss albino mice were sensitised by intraperitoneal injections (administered in three doses at weekly intervals) of CSN or WP from cow or buffalo milk for the evaluation of humoral response and splenocyte stimulation index.

RESULTS

After 3 weeks of intraperitoneal stimulation of mice with milk proteins, the sterilised milk protein group displayed significantly lowered (P ≤ 0.05) serum IgG and IgE levels, while considerably increased cow milk protein-specific responses (IgE) were shown by proteins of pasteurised milk compared with those of raw milk. The stimulation index of splenocytes induced by CSN or WP of boiled and sterilised milk was also lower (P ≤ 0.05) than that of raw milk of both cow and buffalo.

CONCLUSION

The experiment showed that boiling and sterilisation of cow and buffalo milk clearly affect the allergenicity by decreasing the humoral and cell-mediated responses in mice. All results indicated that CSN and WP of sterilised milk are less allergenic than those of raw milk in mice.

Allergic proctocolitis refractory to maternal hypoallergenic diet in exclusively breast-fed infants: a clinical observation

BACKGROUND

Allergic proctocolitis (APC) in exclusively breast-fed infants is caused by food proteins, deriving from maternal diet, transferred through lactation. In most cases a maternal cow milk-free diet leads to a prompt resolution of rectal bleeding, while in some patients a multiple food allergy can occur. The aim of this study was to assess whether the atopy patch test (APT) could be helpful to identify this subgroup of patients requiring to discontinue breast-feeding due to polisensitization. Additionally, we assessed the efficacy of an amino acid-based formula (AAF) when multiple food allergy is suspected. amino acid-based formula

METHODS

We have prospectively enrolled 14 exclusively breast-fed infants with APC refractory to maternal allergen avoidance. The diagnosis was confirmed by endoscopy with biopsies. Skin prick tests and serum specific IgE for common foods, together with APTs for common foods plus breast milk, were performed. After a 1 month therapy of an AAF all patients underwent a follow-up rectosigmoidoscopy.

RESULTS

Prick tests and serum specific IgE were negative. APTs were positive in 100% infants, with a multiple positivity in 50%. Sensitization was found for breast milk in 100%, cow's milk (50%), soy (28%), egg (21%), rice (14%), wheat (7%). Follow-up rectosigmoidoscopy confirmed the remission of APC in all infants.

CONCLUSIONS

These data suggest that APT might become a useful tool to identify subgroups of infants with multiple gastrointestinal food allergy involving a delayed immunogenic mechanism, with the aim to avoid unnecessary maternal dietary restrictions before discontinuing breast-feeding.

The anti-deamidated gliadin peptide antibodies unmask celiac disease in small children with chronic diarrhoea

OBJECTIVES

To assess the usefulness of a new class of antibodies, the anti-deamidated gliadin peptides, in the diagnostic approach to children less than 2 years with suspected celiac disease.

PATIENTS AND METHODS

We investigated 40 children (median age: 16.8 months; age range: 4-24 months), with symptoms and signs of chronic enteropathy and high serum levels of conventional anti-gliadin antibodies, but normal values of anti-transglutaminase and anti-endomysial antibodies; all underwent measurement of anti-deamidated gliadin peptides serum levels, upper gastrointestinal endoscopy with biopsies and HLA typing; 40 subjects served as controls.

RESULTS

In 29 patients (group A) serum levels of anti-deamidated gliadin peptides were normal and duodenal histology showed a spectrum of abnormalities ranging from mucosal inflammatory infiltrates to villous damage (in almost all cases compatible with Marsh 1-to-2 lesions). All improved on a cow's and soy milk free diet containing gluten. In 11 patients (group B) there were high serum levels of anti-deamidated gliadin peptides and histology showed features suggestive of celiac disease (Marsh 2-to-3 lesions) in all; furthermore, human leucocyte antigen typing was consistent with a celiac disease genetic pattern in all. Group B patients significantly improved on a gluten free diet containing cow's and soy milk proteins. None of the control group was anti-deamidated gliadin peptides positive.

CONCLUSIONS

In children younger than 2 years with signs of chronic enteropathy and normal values of classical serum markers of celiac disease, the latter can be predicted by high serum levels of anti-deamidated gliadin peptides.

Selectively high level of serum interleukin 5 in a newborn infant with cow's milk allergy

Cow's milk allergy (CMA) in the neonatal period is thought to include several clinical conditions, yet the pathophysiology remains unclear. We report here the case of a term newborn infant who showed hematochezia 36 hours after the first feeding with cow's milk formula. His serum immunoglobulin E levels were not elevated, although eosinophils were detected in the stool. Elimination of cow's milk formula resolved the symptoms, and from the clinical course and laboratory data the infant was diagnosed with CMA. The serum interleukin 5 (IL-5) (125 pg/mL) level in this patient was selectively elevated. However, serum levels of other T-helper 2 (Th2) cytokines (including IL-4 and IL-13), Th1 cytokines (including interferon γ), and proinflammatory cytokines (including tumor necrosis factor α) were not elevated. These findings suggest that, for this patient, IL-5 and eosinophils might have played a role in the development of neonatal CMA. Although this finding is reported from only 1 case, it highlights the need for serum IL-5 to be determined in more neonatal patients with CMA to further clarify the pathophysiology of this condition in the neonatal period.

Food allergy and autism spectrum disorders: is there a link?

Gastrointestinal (GI) symptoms are common comorbidities in children with autism spectrum disorders (ASDs). Parents often attribute these GI symptoms to food allergy (FA), although an evaluation for IgE-mediated FA is often unrevealing. Our previous studies indicated a high prevalence of non-IgE-mediated FA in young children with ASDs. Therefore, non-IgE-mediated FA may account for some but not all GI symptoms observed in children with ASDs. This raises the question of what treatment measures are applicable to ASD children with GI symptoms. A wide variety of dietary supplements and dietary intervention measures for ASD children have been promoted by medical professionals practicing complementary and alternative medicine despite the lack of rigorous scientific validation in most instances. This review summarizes possible (or proposed) etiologies of GI symptoms in ASD children and discusses risks and possible benefits of intervention measures promoted by complementary and alternative practitioners, with emphasis on FA.

Nonimmunoglobulin e-mediated immune reactions to foods

: Adverse food reactions are abnormal responses to ingested foods. Reactions vary from immunologic to nonimmunologic immune reactions and can be either immunoglobulin E (IgE) mediated or non-IgE mediated. Food-induced IgE-mediated reactions range from localized urticaria to anaphylaxis and have been well studied. However, in comparison, there has been significantly less research into non-IgE-mediated food reactions. Non-IgE-mediated reactions can cause respiratory, gastrointestinal, and cutaneous symptoms. The most recent evidence suggests that these reactions are probably T-cell mediated as evidenced in lymphocyte proliferation assays. This review will explore the symptoms and testing methods of the most common non-IgE-mediated reactions.

Food antigen causes TH2-dependent enteropathy followed by tissue repair in T-cell receptor transgenic mice

BACKGROUND

Clarification of the mechanisms underlying the development of food-sensitive intestinal inflammation will provide an important clue to combating food allergies.

OBJECTIVE

To establish a model of intestinal inflammation caused by oral administration of antigen without additional treatments, we focused on the ovalbumin (OVA) 23-3 T-cell receptor transgenic mouse, which had been reported to have high serum antigen-specific IgE responses to the feeding of an egg white diet.

METHODS

Changes in body weight of mice fed an egg white diet were monitored throughout the 28-day experimental period. After the 28-day feeding, intestinal tissues were harvested for histologic examination. Endogenous production of cytokines and histamine in the jejunum, and production of cytokines secreted by OVA-specific CD4+ T cells purified from mesenteric lymph nodes, were analyzed.

RESULTS

Egg white diet-fed OVA23-3 mice developed weight loss and inflammation with villous atrophy and goblet cell hyperplasia, especially in the jejunum. A further characteristic feature was evidence of weight recovery and tissue repair. Jejunal inflammation was also observed in egg white diet-fed recombination activating gene (RAG)-2-deficient OVA23-3 mice. In addition, tissue sections revealed significant infiltration of specific IgE-positive cells and IgE-positive degranulating mast cells. Higher levels of IL-4 and significant levels of histamine were detected in the tissues. In the supernatant of OVA-stimulated T cells, IL-10 levels were also markedly elevated.

CONCLUSION

We report that high-dose and continuous intake of primitive OVA alone induces enteropathy containing regions under repair in OVA23-3 mice. Antigen-specific T cells and inflammatory cells primed by T(H)2 responses play important roles in regulation of development and improvement of the disease.

CLINICAL IMPLICATIONS

Long-term antigen intake causes T(H)2-dependent and food-sensitive enteropathy followed by tissue repair.

Eosinophils alter colonic epithelial barrier function: role for major basic protein

Mucosal eosinophils increase in a number of gastrointestinal diseases that are often associated with altered epithelial barrier function, including food allergic enteropathies and inflammatory bowel diseases. Although eosinophils are known to secrete biologically active mediators including granule proteins, their role in gastrointestinal diseases is uncertain. The aim of this study was to determine the impact of eosinophils on intestinal barrier function. Epithelial barrier function was determined in a coculture of eosinophils and T84 epithelial cells and in a murine model of T helper (Th) type 2-mediated colitis. Coculture conditions resulted in decreased transepithelial resistance (TER) and increased transepithelial flux. Cell-free coculture supernatants contained a > or =5-kDa soluble factor that also diminished TER; these supernatants contained the eosinophil-granule proteins major basic protein (MBP) and eosinophil-derived neurotoxin (EDN). T84 barrier function decreased significantly when basolateral surfaces were exposed to native human MBP but not EDN. Additional studies identified downregulation of the tight junctional molecule occludin as at least one mechanism for MBP action. MBP-null mice were protected from inflammation associated with oxazolone colitis compared with wild-type mice. In conclusion, MBP decreases epithelial barrier function and in this manner contributes to the pathogenesis of inflammatory bowel diseases.

Gastrointestinal food allergy: new insights into pathophysiology and clinical perspectives

Adverse reactions to food that result in gastrointestinal symptoms are common in the general population; while only a minority of such individuals will have symptoms due to immunologic reactions to foods, gastrointestinal food allergies do exist in both children and adults. These immune reactions are mediated by immunoglobulin E-dependent and -independent mechanisms involving mast cells, eosinophils, and other immune cells, but the complexity of the underlying mechanisms of pathogenesis have yet to be fully defined. Knowledge of the spectrum of adverse reactions to foods that affect the digestive system, including gastrointestinal food allergy, is essential to correctly diagnose and manage the subset of patients with immunologically mediated adverse reactions to foods. Potentially fatal reactions to food necessitate careful instruction and monitoring on the part of health care workers involved in the care of individuals at risk of anaphylaxis. New methods of diagnosis and novel strategies for treatment, including immunologic modulation and the development of hypoallergenic foods, are exciting developments in the field of food allergy.

Oral administration of food antigen induces T cell mediated intestinal inflammation: a model using TCR-transgenic mice

To investigate the mechanisms inducing food-sensitive intestinal inflammation, we focused on the OVA23-3 mouse, a transgenic mouse strain expressing a T cell receptor that recognizes ovalbumin (OVA). Mice administered an egg-white (EW) diet containing OVA showed a trend of loose feces and significant weight loss. Histology of the jejunum showed severe inflammation with villous atrophy. Thus, we studied the role of T cells and intestinal microflora in the development of the inflammation. Severe villous disruption was observed in sections of the jejunum from OVA23-3 mice and RAG-2 gene-deficient OVA23-3 mice fed with EW-diet. Further, a larger number of T cells was found in the lamina propria of the jejunum of EW-diet fed OVA23-3 mice, RAG-2 gene-deficient mice and germfree OVA23-3 mice compared with those of control-diet fed mice. However, severe inflammation was not detected in the jejunum of germfree OVA23-3 mice. CD4+ T cells from the MLN of EW-diet fed OVA23-3 mice showed a Th2 cytokine secretion profile. These observations have thus clarified that antigen-specific Th2 cells play important roles in the development of intestinal inflammation. Although the presence of indigenous bacteria was not essential for the inflammation, T cells could mediate a more severe inflammatory response in their presence.

Cow's milk stimulated lymphocyte proliferation and TNFα secretion in hypersensitivity to cow's milk protein

Although there is no reliable single laboratory test available for the diagnosis of cow's milk allergy, if an allergic mechanism is suspected, a number of laboratory studies may be useful in delineating specific proteins responsible for these disorders. In the current study we analyzed in vitro lymphocyte proliferation assays, specific secretion of TNFalpha in supernatant cultures and specific IgE, IgG, and IgA in a group of patients with hypersensitivity to cow's milk antigens. The stimulation index against a cow's milk antigen mixture, alpha-lactalbumin, beta-lactoglobulin, and casein was significant higher in the group of patients maintained on cow's milk-free diet for less than 4 months compared with the values observed in the control group and in the group of patients without a close contact to cow's milk proteins. A significant increase in TNF-alpha secretion was observed in supernatants from patients with close contact to cow's milk (CM). Specific IgE was detected in 59.3% of the patients, with higher specific IgE levels in patients who were not positive for the proliferation assay, suggesting a clear difference in the two mechanisms proposed as effectors in this disease. No differences in specific IgG and IgA levels were observed between the patient group and the control group, with a great dispersion among individuals in all groups tested. We conclude that a combination of the assays tested in this study, such as proliferative assay of peripheral blood mononuclear cells to CM, the quantitation of TNFalpha in culture supernatants, and serum specific IgE determination, are useful laboratory tests to identify cow's milk allergy among patients with immediate and non immediate adverse reactions, reducing the need for food allergen challenges in young children.

Innate immunity associated with inflammatory responses and cytokine production against common dietary proteins in patients with autism spectrum disorder

OBJECTIVES

Children with autism spectrum disorder (ASD) frequently reveal various gastrointestinal (GI) symptoms that may resolve with an elimination diet along with apparent improvement of some of the behavioral symptoms. Evidence suggests that ASD may be accompanied by aberrant (inflammatory) innate immune responses. This may predispose ASD children to sensitization to common dietary proteins (DP), leading to GI inflammation and aggravation of some behavioral symptoms.

METHODS

We measured IFN-gamma, IL-5, and TNF-alpha production against representative DPs [gliadin, cow's milk protein (CMP), and soy] by peripheral blood mononuclear cells (PBMCs) from ASD and control children [those with DP intolerance (DPI), ASD siblings, and healthy unrelated children]. We evaluated the results in association with proinflammatory and counter-regulatory cytokine production with endotoxin (LPS), a microbial product of intestinal flora and a surrogate stimulant for innate immune responses.

RESULTS

ASD PBMCs produced elevated IFN-gamma and TNF-alpha, but not IL-5 with common DPs at high frequency as observed in DPI PBMCs. ASD PBMCs revealed increased proinflammatory cytokine responses with LPS at high frequency with positive correlation between proinflammatory cytokine production with LPS and IFN-gamma and TNF-alpha production against DPs. Such correlation was less evident in DPI PBMCs.

CONCLUSION

Immune reactivity to DPs may be associated with apparent DPI and GI inflammation in ASD children that may be partly associated with aberrant innate immune response against endotoxin, a product of the gut bacteria.

Food allergy. Mechanisms, diagnosis, and management in children

We eat approximately two to three tons of food in our lifetime, but most people do not have an adverse reaction to foods. Many people believe that they have an allergic reaction to foods; however, the actual incidence confirmed by history and challenges suggests a prevalence rate closer to 2% to 8% in young infants and less than 2% in adults.

Dietary protein enterocolitis

Dietary protein enterocolitis generally presents in the 1st year of life with diarrhea, emesis, and irritability. When there is a delay in diagnosis, persistent exposure to the offending dietary antigen leads to increasing enteric inflammation manifesting as bloody diarrhea, anemia, dehydration, and failure to sustain normal patterns of weight gain and growth. The extent of enteric inflammation may be limited to mild proctitis, pancolitis, or true enterocolitis with esophagitis, gastritis, enteropathy, and colitis. The offending antigen is usually cow's milk protein or soy protein. A significant number of the infants are exclusively breast fed, especially those with proctitis. In older children, a wide variety of dietary proteins have been implicated. The inconsistency between allergists and gastroenterologists in the clinical definition of the syndrome remains a significant problem. To the allergist, the definition is based on clinical criteria, allergy testing, and response to double-blind food challenge, whereas to the gastroenterologist, it is defined by histologic criteria and the response of clinical and histologic manifestations to elimination diets. To further complicate the issue, European studies have emphasized the alterations in enteric permeability noted in both enteropathy and enterocolitis. In an effort to establish a unified approach, the International Life Sciences Institute sponsored a workshop in late 1998, which resulted in a document entitled "Classification of Gastrointestinal Disease of Infants and Children Due to Adverse Immunologic Reactions."

Atopic diseases and upper respiratory infections

This article reviews information on the topics of asthma, atopic dermatitis, food allergy, and upper respiratory infections. The asthma section provides an in-depth look at sociodemographic factors contributing to asthma morbidity and the barriers to asthma control. New findings on the triggers and therapies of atopic dermatitis and new articles on formula allergy and peanut allergy are presented. Recent publications in the areas of sinusitis and upper respiratory infections are also reviewed.

Update in gastrointestinal allergic diseases

Food allergy or hypersensitivity is defined as an adverse reaction to food protein which is immune mediated. Without standard definitions and reliable tests for many forms of allergic disease of the bowel, studies are difficult to interpret. The proceedings of a recent workshop on the classification of adverse immunologic reactions to foods provide the framework for this review. Recent studies have helped define the clinical spectrum and natural history of IgE and non-IgE-mediated food allergy, and provide insight into underlying pathophysiology and dietary management.