Milk-induced reflux in infants less than one year of age

Clinical Presentation and Nutrition Management of Non-IgE-Mediated Food Allergy in Children

Non-IgE-mediated food allergy encompasses a wide spectrum of allergic disorders ranging from mild to severe presentations, including food protein-induced allergic proctocolitis, food protein-induced enterocolitis syndrome, and food protein-induced enteropathy. Other gastrointestinal symptoms such as constipation and gastroesophageal reflux disease have not previously been recognised as symptoms of non-IgE-mediated food allergy in food allergy guideline publications. Recently, two new consensus documents from the European Academy of Allergy, Asthma and Immunology address a potential role of food allergens in these disorders, where standard treatment has failed, and provide guidance for diagnosis and management of these conditions. Additional updates include the World Allergy Organisation guidance on the diagnosis and management of cow's milk allergy, the most commonly implicated food in non-IgE-mediated food allergy. These documents all help practitioners to distinguish between common manifestations in infancy that are not pathologic and non-IgE-mediated food allergy. Understanding diagnostic criteria is vital to prevent overdiagnosis, limit unnecessary elimination diets and preserve breastfeeding. Conversely, proper diagnosis may reduce symptoms in infants who are affected. Therefore, the first step in management of non-IgE-mediated food allergy is establishing a correct diagnosis, which requires understanding the clinical presentations and if needed, applying an appropriate short-term diagnostic elimination diet to observe for symptom resolution, followed by food reintroduction to assess for symptom recurrence. Once diagnosed, treatment requires removal of the trigger food, most commonly cow's milk, which is not without burden and nutrition risk. Non-IgE-mediated food allergies typically resolve early in childhood with some disorders resolving in infancy therefore early reassessment for tolerance is vital. Management of non-IgE-mediated food allergy entails following diagnostic algorithms, developing an individualised dietary plan, and timely assessment of tolerance development to reduce burden and nutrition risk.

Diagnosis and management of food allergy-associated gastroesophageal reflux disease in young children-EAACI position paper

Gastro-oesophageal reflux (GOR) and food allergy (FA) are common conditions, especially during the first 12 months of life. When GOR leads to troublesome symptoms, that affect the daily functioning of the infant and family, it is referred to as GOR disease (GORD). The role of food allergens as a cause of GORD remains controversial. This European Academy of Allergy and Clinical Immunology (EAACI) position paper aims to review the evidence for FA-associated GORD in young children and translate this into clinical practice that guides healthcare professionals through the diagnosis of suspected FA-associated GORD and medical and dietary management. The task force (TF) on non-IgE mediated allergy consists of EAACI experts in paediatric gastroenterology, allergy, dietetics and psychology from Europe, United Kingdom, United States, Turkey and Brazil. Six clinical questions were formulated, amended and approved by the TF to guide this publication. A systematic literature search using PubMed, Cochrane and EMBASE databases (until June 2021) using predefined inclusion criteria based on the 6 questions was used. The TF also gained access to the database from the European Society of Paediatric Gastroenterology and Hepatology working group, who published guidelines on GORD and ensured that all publications used within that position paper were included. For each of the 6 questions, practice points were formulated, followed by a modified Delphi method consisting of anonymous web-based voting that was repeated with modified practice points where required, until at least 80% consensus for each practice point was achieved. This TF position paper shares the process, the discussion and consensus on all practice points on FA-associated GORD.

The effect of a low-nickel diet and nickel sensitization on gastroesophageal reflux disease: A pilot study

BACKGROUND/AIMS

Gastroesophageal reflux disease (GERD) is a common medical condition, frequently refractory to medical therapy. Nickel is a leading cause of allergic contact dermatitis. Although nickel is widely found in foods, the effect of nickel on GERD is unknown. This pilot study sought to evaluate the effect of a low-nickel diet on GERD and determine if epicutaneous patch testing to nickel could predict responsiveness to a low-nickel diet.

METHODS

This prospective, single-site pilot study recruited 20 refractory GERD patients as determined by GERD Health-Related Quality of Life (GERD-HRQL) scores. All patients had epicutaneous patch testing for nickel and were then instructed to follow a low-nickel diet for 8 weeks regardless of patch test results. GERD-HRQL was recorded at baseline and following 8 weeks of a low-nickel diet. Demographic and clinical data associated with GERD and nickel allergy were recorded. A Wilcoxon signed-rank test and nonparametric analysis of longitudinal data were run to determine statistical significance in pre- and post- GERD-HRQL scores in nickel patch test-positive and negative groups.

RESULTS

Nearly all (19/20 [95%]) participants reported reduced GERD symptoms after 8 weeks on a low-nickel diet. Mean total GERD-HRQL, regurgitation, and heartburn scores declined (27.05 ± 16.04, 11.45 ± 6.46, 10.85 ± 8.29). Participants with positive vs. negative patch testing to nickel responded equivalently to a low-nickel diet.

CONCLUSIONS

A low-nickel diet improves GERD symptoms, but responsiveness to a low-nickel diet does not correlate with epicutaneous patch testing to nickel.

TRIAL REGISTRATION

ClinicalTrials.gov number: NCT03720756.

Impact of Gastroesophageal Reflux Disease on Mucosal Immunity and Atopic Disorders

Atopic disorders and gastroesophageal reflux disease (GERD) are some of the most common medical conditions treated by primary care physicians and specialists alike. The observation that atopic disorders, like asthma, allergic rhinitis and sinusitis, food allergies, atopic dermatitis, contact dermatitis, and eosinophilic esophagitis are common comorbidities in patients with GERD raises the question of the nature of the relationship that may exist between GERD and atopic disorders. In this article, we review the pathophysiology of GERD, its effect on the immune system, the effect of acid-blocking medications on allergic responses, as well as several common atopic conditions that have been associated with GERD including asthma, chronic rhinosinusitis (CRS), allergic rhinitis (AR), atopic dermatitis (AD), contact dermatitis (CD), food allergies, proton pump inhibitor (PPI)-responsive esophageal eosinophilia (PPI-REE), and eosinophilic esophagitis (EoE). In each condition, the evidence of a causal link is not definitive. Although the relationship between asthma and GERD remains controversial, evidence suggests that a subset of asthma patients with documented GERD may experience improved asthma control following appropriate treatment of GERD. The relationship of GERD to allergic rhinitis and chronic sinusitis is weak; however, studies support the concept that treatment of frequent episodes of GERD can have a positive effect on rhinitis and sinusitis overall. The relationship between allergic sensitization and GERD is likely bidirectional. GERD may induce changes in the mucosal immune system that may favor the development of food allergy and allergic sensitization to aeroallergens; however, the underlying mechanisms have not been established.

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.

Food allergy in children with refractory gastroesophageal reflux disease

BACKGROUND

Gastroesophageal reflux disease (GERD) and food allergy are frequent disorders of childhood. The purpose of this study was to determine the frequency of food allergy in children with refractory GERD.

METHODS

A total of 151 children resistant to pharmacologic GERD treatment underwent skin prick test, specific immunoglobulin E, eosinophil count, atopy patch test (APT), and oral food challenge, and were then divided into three groups according to the results of oral milk challenge and allergy work-up: group A1, positive oral milk challenge and positive IgE-mediated allergy test; group A2, positive milk challenge and negative IgE-mediated allergy test; and group B, negative oral milk challenge and negative allergy tests.

RESULTS

There were 35, 30 and 86 patients in group A1, group A2 and group B, respectively. A total of 28 of 35 patients in group A1 had cow's milk allergy and the other seven patients had egg allergy. APT positivity was more common in group A2. Endoscopic esophagitis was observed in six group A1 patients and in four group A2 patients. Bloody stools, atopic dermatitis and recurrent wheezing episodes were significantly more common in group A1 than in group A2 and group B (P < 0.001, for both).

CONCLUSION

Cow's milk allergy was observed frequently in children resistant to pharmacologic GERD treatment. Combined skin prick and specific IgE tests, APT and oral food challenge is essential for avoidance of unnecessary elimination diet.

Medical intervention in parent-reported infant gastro-oesophageal reflux: A population-based study

AIM

To report the cumulative incidence, health-seeking behaviour and medical intervention of infants with gastro-oesophageal reflux (GOR) in the first year of life.

METHODS

The HealthNuts study is a longitudinal, population-based study. At 12 months of age, infants underwent skin prick testing to food allergens, including cows milk. Parents completed a questionnaire on GOR symptoms, food allergy and treatments. Factors associated with seeking health care for infants with GOR were modelled using logistic regression.

RESULTS

Of 4674 infants, parents reported GOR in 1054 (23%; 95% confidence interval (CI) 21.4-23.8). Parents consulted a medical practitioner in 662 (64%) cases. Symptoms commenced in the first month in 411 (48%) and resolved within 6 months in 703 (75%) infants. Factors associated with doctor consultation for GOR were prematurity (adjusted odds ratio (aOR) 1.94; 95% CI 1.43-2.63) and family history of atopy (aOR 1.64; 95% CI 1.1-2.43). Eight per cent of infants (371/4674; 95% CI 7.2-8.7) received anti-reflux medication and 6% (296/4674; 95% CI 5.7-7.1) changed formula. Parents were more likely to seek treatment if they perceived their infant to be unsettled (aOR 2.55; 95% CI 1.26-5.17) and if the duration of GOR was prolonged (aOR 3.36 for symptoms >6 months; 95% CI 1.83-6.17).

CONCLUSIONS

In the first year of life, approximately 14% of the population seek medical advice for GOR symptoms. The use of anti-reflux medication in the general community remains high, despite the absence of evidence that it is appropriate or effective for uncomplicated GOR.

Managing gastroesophageal reflux symptoms in the very low-birth-weight infant postdischarge

Gastroesophageal reflux and gastroesophageal reflux disease symptoms are common challenges for very low-birth-weight infants (<1500 g). These symptoms frequently result in feeding difficulties and family stress. Management of symptoms across healthcare disciplines may not be based on current evidence, and inconsistency can result in confusion for families and delayed interventions. The feeding relationship between infant and caregivers may be impaired when symptoms are persistent and poorly managed. An algorithm for managing gastroesophageal reflux-like symptoms in very low-birth-weight infants (from hospital discharge to 12 months corrected age) was developed through the formation of a multidisciplinary community of practice and critical appraisal of the literature. A case study demonstrates how the algorithm results in a consistent approach for identifying symptoms, applying appropriate management strategies, and facilitating appropriate timing of medical consultation. Application to managing gastroesophageal reflux symptoms in the neonatal intensive care unit will be briefly addressed.

Extensively hydrolyzed protein formula reduces acid gastro-esophageal reflux in symptomatic preterm infants

BACKGROUND

Gastro-esophageal reflux (GER) is diagnosed frequently in preterm infants. Pharmacological treatment of GER has some potential side effects. Conservative treatment of GER should be the first-line approach and should include body positioning and diet modifications. Formula-fed preterm infants experience frequently symptoms of feeding intolerance. Hydrolyzed protein formula (HPF) is often used in these infants due to their effects on gastrointestinal motility.

AIMS

To investigate the role of an extensively HPF (eHPF) on GER indexes in formula-fed preterm infants with symptoms of both GER and feeding intolerance.

STUDY DESIGN

Randomized crossover trial.

SUBJECTS

Preterm infants (gestational age ≤33 weeks) with symptoms of feeding intolerance (large gastric residuals, abdominal distension and constipation) and GER (frequent regurgitations and/or postprandial desaturations).

OUTCOME MEASURES

GER indexes detected by 24-h combined multichannel intraluminal impedance and pH monitoring. GER indexes detected after 4 feeds of an eHPF were compared to those detected after 4 feeds of a standard preterm formula (SPF) by Wilcoxon signed ranks test. A p<0.05 was considered statistically significant.

RESULTS

eHPF significantly reduced the number of GERs detected by pH monitoring (p=0.036) and also the reflux index (p=0.044) compared to SPF. No differences in impedance bolus exposure indexes nor in GER height were detected.

CONCLUSIONS

The use of an eHPF should be evaluated for reducing esophageal acid exposure in preterm infants with feeding intolerance and symptoms of GER. Future research should focus on the evaluation of an eHPF adequate for preterm infants in improving clinical symptoms of GER.

Cow's Milk Allergy among Children with Gastroesophageal Reflux Disease

Background/Aims

Gastroesophageal reflux disease (GERD) and cow's milk allergy (CMA) are two common conditions that occur in infancy. This study was performed to investigate the frequency of CMA in a group of patients with GERD.

Methods

Eighty-one children with signs and symptoms of GERD were enrolled in this study. All subjects received omeprazole for 4 weeks after the initial evaluation. Empirical elimination of cow's milk from the diet was started for the patients who did not respond to the omeprazole treatment.

Results

Seventy-two cases presented with gastrointestinal signs and symptoms, whereas the remaining nine cases presented with respiratory complaints. After the initial treatment with omeprazole, two thirds of the cases (54 patients, 66.7%) responded well, and all of their symptoms were resolved. Cow's milk was eliminated from the diets of the remaining 27 patients. All signs and symptoms of GERD were resolved in this group after a 4 week elimination of cow's milk from the diet.

Conclusions

A diagnosis of CMA was considered in one third of the pediatric cases with signs and symptoms of GERD. This finding shows that CMA can mimic or aggravate all signs and symptoms of severe GERD during infancy.

Pediatric gastroesophageal reflux clinical practice guidelines: joint recommendations of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN)

OBJECTIVE

To develop a North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) and European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) international consensus on the diagnosis and management of gastroesophageal reflux and gastroesophageal reflux disease in the pediatric population.

METHODS

An international panel of 9 pediatric gastroenterologists and 2 epidemiologists were selected by both societies, which developed these guidelines based on the Delphi principle. Statements were based on systematic literature searches using the best-available evidence from PubMed, Cumulative Index to Nursing and Allied Health Literature, and bibliographies. The committee convened in face-to-face meetings 3 times. Consensus was achieved for all recommendations through nominal group technique, a structured, quantitative method. Articles were evaluated using the Oxford Centre for Evidence-based Medicine Levels of Evidence. Using the Oxford Grades of Recommendation, the quality of evidence of each of the recommendations made by the committee was determined and is summarized in appendices.

RESULTS

More than 600 articles were reviewed for this work. The document provides evidence-based guidelines for the diagnosis and management of gastroesophageal reflux and gastroesophageal reflux disease in the pediatric population.

CONCLUSIONS

This document is intended to be used in daily practice for the development of future clinical practice guidelines and as a basis for clinical trials.

Reflux oesophagitis in children; the role of endoscopy. A multicentric Italian survey

BACKGROUND

The decision whether to perform endoscopy in children with suspected reflux oesophagitis is not a straightforward one. Few symptoms are specific for oesophagitis and the diagnosis is not always correlated even to visual findings on endoscopy.

AIM

The aim of this study was to define the role of endoscopy and especially of histology in the diagnosis of reflux oesophagitis and to examine the correlations between symptoms, endoscopic findings and histology in children with suspected gastroesophageal reflux disease.

PATIENTS AND METHODS

One hundred and thirty-six patients with a clinical diagnosis of reflux oesophagitis, aged 1-18 years (mean 8.43; standard deviation +/-4.4), were enrolled from 12 Italian Paediatrics Gastroenterology Centres; symptom score, endoscopic and histologic oesophagitis scores were observed before and after therapy with proton pump inhibitors.

RESULTS

Before therapy, a high correlation between the prevailing symptom score and endoscopic score was demonstrated, but not with histologic score: there was a significant tendency for histologic grade to exceed visual findings. After therapy, endoscopic score and histologic score were significantly improved.

CONCLUSIONS

Oesophageal biopsies increase the diagnostic accuracy of upper endoscopy. Histologic grading is often much more important than the endoscopic appearance, so that endoscopic oesophageal biopsies are very important aids in the diagnosis of oesophagitis. Appropriate clinical evaluation of symptoms must occur before endoscopic examination.

Gastrointestinal symptoms in infancy: a population-based prospective study

BACKGROUND

During the first months of life, infants can suffer from many 'minor' gastroenterological disturbances. However, little is known about the frequency of these problems and the factors which predispose or facilitate their onset.

AIMS

(a) To ascertain the frequency of the most common gastrointestinal symptoms in infants during the first 6 months after birth; (b) to evaluate the influence of some variables on the onset of the symptoms.

STUDY DESIGN AND PATIENTS

Each of the 150 paediatricians distributed throughout Italy followed 20 consecutive infants from birth to 6 months. 2879 infants (1422 f, 1457 m) concluded the study. The presence of the following symptoms was evaluated: constipation, diarrhoea, vomiting, regurgitation, failure to thrive and prolonged crying fits (colic). Symptoms were recorded whenever the parents requested a clinical check-up or during a set monthly examination.

RESULTS

1582/2879 (54.9%) infants suffered from one of the gastrointestinal symptoms. Regurgitation was the most common disturbance (present in 23.1% of infants), followed by colic (20.5%), constipation (17.6%), failure to thrive (15.2%), vomiting (6%) and diarrhoea (4.1%). Low birth weight was the factor most frequently associated with the onset of gastrointestinal symptoms, followed by low gestational age. Feeding habits did not influence the onset of symptoms, with the exception of constipation, which was linked to a low frequency of breast-feeding. Ninety-three infants (3.2%) were hospitalised for one or more of the gastrointestinal symptoms which were considered. During the whole study period the type of formula-milk was changed in 60% of the infants with one or more gastrointestinal symptoms, and in 15.5% of the infants who did not suffer from any gastrointestinal troubles.

CONCLUSIONS

Gastrointestinal symptoms are very common in infants during the first 6 months after birth. These symptoms required hospitalisation only in a small percentage of cases, but led to the prescription of a 'dietary' milk formula in approximately 60% of the cases. Low birth weight and low gestational age were the main factors influencing the onset of the symptoms.

Excessive crying and gastro-oesophageal reflux disease in infants: misalignment of biology and culture

Excessive crying is the most common problem presenting to the doctor in the first months of life in western industrialised societies, affecting up to 30% of infants. There has been an exponential increase in the diagnosis of gastro-oesophageal reflux disease (GORD) in babies who cry excessively over the past few decades, and many parents believe their crying infant "has reflux". This paper proposes that culturocentric assumptions have confused interpretation of research into GORD, and re-examines the findings of GORD research from the perspective of evolutionary biology. Evolutionary biologists argue that the human infant is an exterogestate foetus for at least the first six months of life, dependent on maternal co-regulation for optimal physiological function. However, infant-care practices in western industrialised societies shifted towards an emphasis on infant autonomy at the time of the Industrial Revolution. From the perspective of evolutionary biology, a misalignment between western culture and the biological expectations of the infant developed over two million years of evolution may result in excessive crying in less adapted babies. The key biocultural factors that impact on infant distress are feeding management, parental responsiveness, sensory nourishment and sleep management. When the concept of the human infant as an exterogestate foetus is integrated with the findings of GORD research, a hypothesis and its corollary emerge. This hypothesis proposes that infant GORD is a physiological manifestation of misalignment between biology and culture, and proposes, as a corollary, that if the impact of biocultural factors upon the physiology of otherwise well crying babies is not addressed in the first months of life, populations of infants who cry excessively may be predisposed to GORD after three to four months of age. If this hypothesis is correct, an integrated clinical approach to crying babies less than three to four months of age that considers feeding management (e.g., frequent feeds, breast- or bottle-feeding technique, referral to a lactation consultant, cow's milk allergy), parental responsiveness (e.g., prompt response to infant cues), sensory nourishment (e.g., sling or backpack, walks, massage) and sleep management (e.g., nocturnal co-sleeping) should, firstly, decrease crying when applied to infants less than three to four months of age, and secondly, decrease the incidence of GORD in these infants once they are older than three to four months of age. Thirdly, if this hypothesis is correct, combining the integrated approach with pharmaceutical intervention should improve outcomes in infants diagnosed with GORD.

Severe gastroesophageal reflux disease and cow milk hypersensitivity in infants and children: disease association and evaluation of a new challenge procedure

BACKGROUND

Gastroesophageal reflux disease (GERD) and cow milk hypersensitivity are frequent disorders of infancy. A possible causative association between these two entities has been suggested.

OBJECTIVE

The primary aim was to elucidate whether a causative relationship between the two entities could be established in a population of infants and children. A secondary aim was to evaluate whether cow milk challenge during esophageal pH monitoring is useful as an objective method to identify this subgroup of patients.

METHODS

Upper endoscopy followed by a 48-hour esophageal pH monitoring with cow's milk elimination diet at day 1 and challenge at day 2. Cow milk hypersensitivity was later verified by elimination diet and a second open (in patients < 3 years of age) or double-blind placebo-controlled (in patients > or = 3 years of age) challenge. Skin prick test, specific serum immunoglobulin E and skin patch test were used as supplementary procedures. Follow-up endoscopy and pH monitoring were performed after 3 months of treatment (omeprazole versus elimination diet dependent on evidence of food hypersensitivity).

RESULTS

Eighteen of 42 investigated patients had severe GERD, defined as endoscopic esophagitis and/or a reflux index > 10%. Among these patients, a group of 10 patients with GERD and cow milk hypersensitivity was identified. This group had a significantly higher reflux index compared with children with primary GERD. No significant increase was noted in reflux index during simultaneous pH monitoring and milk challenge.

CONCLUSIONS

An association between GERD and cow milk hypersensitivity was observed in both infants and children with severe GERD. Simultaneous cow milk challenge and pH monitoring had limited value as a method to identify this subgroup.

Chemokines in eosinophil-associated gastrointestinal disorders

Eosinophil-associated gastrointestinal disorders (EGDs) are characterized by a pronounced cellular inflammation. Recent clinical and experimental investigations have implicated a family of molecules known as chemokines in the regulation of leukocyte recruitment in these diseases. The underlying cellular and molecular mechanisms involved in chemokine-mediated cellular infiltration are largely unknown. In this review, we describe the role of CD4+ T cells and eosinophils in the clinical manifestations of EGDs and discuss the current understanding of the role of chemokines in the recruitment of these cells in the expression of diseases.

Gastroesophageal reflux and cow milk allergy: is there a link?

Gastroesophageal reflux (GER) and cow milk allergy (CMA) occur frequently in infants younger than 1 year. In recent years, the relation between these 2 entities has been investigated and some important conclusions have been reached: in up to half of the cases of GER in infants younger than 1 year, there may be an association with CMA. In a high proportion of cases, GER is not only CMA associated but also CMA induced. The frequency of this association should induce pediatricians to screen for possible concomitant CMA in all infants who have GER and are younger than 1 year. With the exception of some patients with mild typical CMA manifestations (diarrhea, dermatitis, or rhinitis), the symptoms of GER associated with CMA are the same as those observed in primary GER. Immunologic tests and esophageal pH monitoring (with a typical pH pattern characterized by a progressive, slow decrease in esophageal pH between feedings) may be helpful if an association between GER and CMA is suspected, although the clinical response to an elimination diet and challenge is the only clue to the diagnosis. This article reviews the main features of GER and CMA, focusing on the aspects in common and the discrepancies between both conditions.

Prevalence of gastro-esophageal reflux-related symptoms in Japanese infants

BACKGROUND

To obtain precise information on the natural course of gastro-esophageal reflux (GER)-related symptoms in Japanese children, we surveyed the prevalence of regurgitation or vomiting and other GER-related symptoms and complications in infants visiting for healthy baby check-ups.

METHODS

We interviewed the mothers of 921 infants who had visited for baby check-ups at 1, 4, 7 and 12 months after birth, about the number of regurgitation or vomiting episodes per day, other GER-related symptoms, milk volume, feeding interval, and the body position after feeding.

RESULTS

Of 1-month-old infants, 47.1% had one or more regurgitation or vomiting episode per day. This proportion decreased to 28.8% at 4 months old and 6.4% at 7 months old. The proportion of infants with three or more episodes of these symptoms per day showed a similar pattern. There was no significant difference in the prevalence of regurgitation or vomiting between breast-fed infants and formula-fed or mixed-feeding infants either at 1 or 4 months of age. There was no significant difference in the bodyweight gain of 3-month-old infants among those with various degrees of regurgitation. There was no significant difference in the frequency of regurgitation or vomiting episodes between infants placed in a vertical position and those placed in a horizontal position after feeding. No infant had a history of chronic coughing, wheezing, bleeding or other serious conditions.

CONCLUSIONS

Regurgitation is a common symptom in Japanese infants and decreases spontaneously with age. The natural history of GER must be taken into consideration when deciding the treatment.

Experimental analysis of eosinophil-associated gastrointestinal diseases

Eosinophil infiltration into the gastrointestinal tract occurs in a wide range of diseases. However, the underlying cellular and molecular mechanisms involved in eosinophil migration and the role of eosinophils in disease pathogenesis are largely unknown. Recent studies using experimental models of eosinophil-associated gastrointestinal allergy have revealed differential roles for IL-5 and eotaxin in the modulation of eosinophil accumulation into various regions of the gastrointestinal tract. Furthermore, such studies have revealed a possible role for eosinophils in the pathogenesis of gastrointestinal disorders. The present review describes the clinical manifestations of various eosinophil-associated gastrointestinal disorders and the current understanding of the role of IL-5 and eotaxin in the allergic inflammatory response, and the participation of the eosinophilic granulocyte in the expression of disease.

Prevalence and natural course of gastroesophageal reflux symptoms: a 1-year cohort study in Thai infants

BACKGROUND

Epidemiologic studies in adults suggest that the nature of gastroesophageal reflux may differ among various ethnic groups. Until recently, there has been limited information concerning the epidemiology of gastroesophageal reflux in non-Western children. The objectives of this cohort study were to investigate the prevalence of symptoms related to gastroesophageal reflux in Thai infants and to describe the clinical course of reflux regurgitation during the first year of life.

METHODS

A cohort study was performed in 216 healthy neonates who attended the well-baby clinic of Songklanagarind Hospital between March and June 1998. All neonates were followed up, at regular well-baby clinic visits, for 1 year for reflux symptoms and clinical progress. Information concerning gastroesophageal reflux symptoms was obtained by interviewing the parents and from their diary records. An infant who regurgitated at least 1 day per week was considered to have reflux regurgitation.

RESULTS

No infant with clinical features of pathologic gastroesophageal reflux or other reflux symptoms apart from regurgitation were seen during this study period. Of 145 infants in a 1-year cohort, the prevalence of reflux regurgitation peaked at 2 months at 86.9% and significantly decreased to 69.7% at 4 months, 45.5% at 6 months, and 22.8% at 8 months. At 1 year of age, only 7.6% of infants still had reflux regurgitation. Most Thai infants with gastroesophageal reflux had mild symptoms: 90% of them regurgitated only one to three times per day, and daily regurgitation was reported in a low percentage. Comparing infants with reflux regurgitation and those without, the standard deviation scores of body weight for age were similar. There was no significant difference in prevalence of reflux regurgitation between breast-fed and bottle-fed infants.

CONCLUSIONS

The nature of gastroesophageal reflux in Thai infants differs from that in Western infants. The prevalence of reflux regurgitation in Thai infants was very high at 1 to 2 months of age; however, many infants became symptom-free by 6 months. The type of feeding (breast milk vs. bottle milk) had no influence on the prevalence of reflux regurgitation.

The immunologic basis for intestinal food allergy

There has been considerable recent broadening of basic concepts of intestinal food allergy, in particular the importance of non-IgE-mediated mechanisms. The traditional emphasis on IgE-mediated allergy now appears inappropriate in light of current studies of the basic mechanisms of oral tolerance to dietary antigen and of increasing recognition of the requirement for early infectious challenge in the prevention of allergic sensitization. This major change in emphasis has been forced both by basic scientific studies and by recognition of novel patterns of food allergic disease within the pediatric population, in which rapid increase in food-allergic sensitization has been noted in the last decade and previously rare phenomena such as multiple food allergies and sensitization of exclusively breast-fed infants to antigens eaten by the mother have become commonplace. It is thus emerging that the possession of exaggerated IgE responses may not be the direct cause of food allergic sensitization but may ensure that such sensitization is clinically obvious. Those without such immediate responses have a complex of symptoms, including diet-responsive eczema and a marked disturbance of intestinal motility. The clear demographic links with socioeconomic privilege and relative protection from gastrointestinal infarctions concord with recent murine data suggesting an obligatory input from innate immune responses to the gut flora in the establishment of oral tolerance.

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.

Reflux in children

Gastro-oesophageal reflux (GOR) is an extremely common paediatric problem that often runs a harmless and self-limited course. Physiological GOR however can lead to marked parental anxiety, many unnecessary investigations and often unwarranted and potentially harmful therapeutic interventions. Our ability to better define GOR and gastro-oesophageal reflux disease (GORD) has improved in the past 15 years with a better understanding of the pathophysiology in infants and children due to the development and wider use of flexible endoscopy, 24-hour oesophageal pH monitoring and, more recently, the use of micromanometric methods for studying oesophageal motility. This will be further enhanced in the future with the development of non-invasive breath testing to study gastrointestinal motility and the use of electrical impedance to study fluid movement. Our therapeutic interventions have also improved particularly in the areas of acid suppression, improved surgical techniques and most recently laparoscopic fundoplication. This chapter reviews these advances in the paediatric area especially with regard to pathophysiology, diagnostic testing and therapeutic intervention.