Dietary protein-induced proctocolitis in childhood

Non-immunoglobulin E-mediated food allergy

Non-immunoglobulin E (IgE)-mediated food allergies are characterized by delayed gastrointestinal (GI) manifestations that occur after exposure to an inciting food protein; they include food protein-induced allergic proctocolitis (FPIAP), food protein-induced enteropathy (FPE), and food protein-induced enterocolitis syndrome (FPIES). Although the exact mechanisms underlying these disorders are not well understood, non-IgE-mediated food allergies likely represent a spectrum of disease with shared pathophysiological processes. Typically, these non-IgE-mediated food allergies begin in infancy or early childhood, although FPIES can present across the lifespan, with increasing reports in adults in recent years. Diagnosing non-IgE-mediated food allergies can be challenging due to the lack of noninvasive confirmatory tests or biomarkers for most of these disorders and the non-specific nature of GI symptoms. Thus, the diagnosis is usually made clinically, and relies on a constellation of typical symptoms that improve upon removal of the culprit food. The primary approach to management of FPIAP, FPE and FPIES is avoidance of the triggering food, and a multidisciplinary management approach that includes allergy/immunology may be required to avoid unnecessary food restriction and guide food reintroduction. This review outlines the clinical manifestations, epidemiology, pathophysiology, diagnosis, management, and prognosis of these non-IgE-mediated food allergies.

Elimination Diets in Lactating Mothers of Infants with Food Allergy

Breastfeeding is the most important nutrition source for infants. However, managing breastfed infants with signs and symptoms related to food allergy can be difficult. Many studies have shown the presence of different food allergens in breast milk, but the clinical role of these antigens in human milk is still much debated. Milk is the main suspect in exclusively breastfed infants with signs and symptoms attributable to food allergy, even if other foods may be responsible. This narrative review analyzes the recommendations provided by international guidelines to determine the diagnosis and management of IgE-mediated and non-IgE-mediated food allergies in exclusively breastfed infants. Dietary restrictions in lactating mothers of infants with suspected FA are usually not necessary. Only in the very few cases where significant allergy signs and symptoms occur in the infant during exclusive breastfeeding should the lactating mother follow an elimination diet for the suspected food for a short period.

Allergic Proctocolitis: Literature Review and Proposal of a Diagnostic-Therapeutic Algorithm

Allergic proctocolitis (AP) is a benign condition, frequent in childhood, that is classified as a non-IgE-mediated food allergy. The prevalence is unknown; however, its frequency appears to be increasing, especially in exclusively breastfed infants. Clinical manifestations typically begin in the first few months of life with the appearance of bright red blood (hematochezia), with or without mucus, in the stool of apparently healthy, thriving infants. Most cases of AP are caused by cow's milk proteins; however, other allergens, such as soy, egg, corn, and wheat, may be potential triggers. Diagnosis is based on the patient's clinical history and on the resolution of signs and symptoms with the elimination of the suspected food antigen from the diet and their reappearance when the food is reintroduced into the diet. The treatment of AP is based on an elimination diet of the trigger food, with resolution of the symptoms within 72-96 h from the beginning of the diet. The prognosis of AP is good; it is a self-limiting condition, because most children can tolerate the trigger food within one year of life, with an excellent long-term prognosis. The purpose of this review is to provide an update on the current knowledge and recommendations in epidemiological, diagnostic, and therapeutic terms to the pediatricians, allergists, and gastroenterologists who may find themselves managing a patient with AP.

Perspectives on Non-IgE-Mediated Gastrointestinal Food Allergy in Pediatrics: A Review of Current Evidence and Guidelines

Food allergy is an immune-mediated disease that can result in considerable morbidity and even mortality, with a significant negative impact on patients' quality of life. It is characterized by allergic symptoms that can occur shortly after a relevant food allergen ingestion, or can be delayed or chronic, which make it more difficult for diagnosis. The symptoms of this disease can range from mild to severe, and rarely can cause anaphylaxis, a life-threatening allergic reaction. The prevalence of non-immunoglobulin E (IgE)-mediated food allergy is poorly established outside of cow's milk allergy, with an adjusted incidence ranging between 0.13% and 0.72%. Several disorders are classified as non-immunoglobulin E (IgE)-mediated food allergies that predominantly affect the gastrointestinal tract including food protein-induced enterocolitis syndrome (FPIES), food protein-induced allergic proctocolitis (FPIAP), food protein-induced allergic enteropathy (FPE), and food protein-induced dysmotility disorders (GORD and constipation). Eosinophilic esophagitis (EoE) is listed in this group, even though it considered by some authorities to be mixed reaction with both IgE and cell-mediated immune response to be involved in the reaction. The most common types of non-IgE-mediated food allergy are food protein-induced enterocolitis syndrome (FPIES) and food protein-induced allergic proctocolitis (FPIAP). These disorders typically present in infancy and are often triggered by cow's milk protein. Patients with FPIES present with profuse emesis and dehydration, while FPIAP patients present with hematochezia in otherwise healthy infants. Since there are no specific confirmatory non-invasive diagnostic laboratory tests, the diagnosis is usually made clinically when typical symptoms improve upon the removal of the culprit food. Food reintroduction should be attempted, when possible, with documentation of symptoms of relapse to confirm the diagnosis. The management includes dietary avoidance, supportive treatment in the case of accidental exposure, and nutritional counseling. This review focuses on the clinical manifestations, epidemiology, management, and recent guidelines of the most common non-IgE-mediated food hypersensitivity disorders (FPIES, FPIAP, and FPE).

The in vitro antiviral activity of Lacticaseibacillus casei MCJ protein-based metabolites on bovine viral diarrhea virus

Bovine viral diarrhea virus (BVDV) is a ubiquitous immunosuppressive etiological agent which is economically important for a wide host range in the livestock industry. Lactobacillus spp. has widely been using in the field of management and treatment of gastro-enteric disease for both humans and animals. The ability of Lacticaseibacillus casei MCJ protein-based metabolized to suppress BVDV infection in Madin-Darby Bovine Kidney cell line was demonstrated in this study. The protein-based metabolites were extracted from the cultured L. casei to obtain the safest and beneficial form of the probiotic bacteria. It is revealed that LPM have no cytotoxic effect and the cell viability remain more than 80% even after the cells are treated with 3000 µg/mL of LPM. The results of the plaque formation assay showed that LPM can reduce the viral infection rate. To know the mechanism of LPM for anti-BVDV activity, MDBK cells were exposed to LPM before, after and co-incubation of virus infection. The co-treatment of LPM with BVDV revealed the best results. The results suggest that the LPM has a potential anti-BVDV activity which could be a prospective candidate for the prevention and control of BVDV infection in an animal.

Food protein-induced proctocolitis and enteropathy

Non-IgE (immunoglobulin E) mediated gastrointestinal food allergies include several separate clinical entities, including food protein-induced allergic proctocolitis (FPIAP) and food protein-induced enteropathy (FPE). Although FPIAP and FPE both primarily affect the gastrointestinal tract, their presentations are vastly different. FPIAP presents with bloody stools in otherwise healthy infants, whereas FPE presents with chronic diarrhea, vomiting, malabsorption, and hypoproteinemia. These both typically present in infancy and resolve by early childhood. Although the presenting signs and symptoms may be different, management is similar in that both require avoidance of the suspected causal food.

Non-IgE-Mediated Gastrointestinal Food Allergies in Children: An Update

Non-immunoglobulin E-mediated gastrointestinal food allergic disorders (non-IgE-GI-FA) include food protein-induced enterocolitis syndrome (FPIES), food protein-induced enteropathy (FPE) and food protein-induced allergic proctocolitis (FPIAP), which present with symptoms of variable severity, affecting the gastrointestinal tract in response to specific dietary antigens. The diagnosis of non-IgE-GI-FA is made clinically, and relies on a constellation of typical symptoms that improve upon removal of the culprit food. When possible, food reintroduction should be attempted, with the documentation of symptoms relapse to establish a conclusive diagnosis. Management includes dietary avoidance, nutritional counselling, and supportive measures in the case of accidental exposure. The prognosis is generally favorable, with the majority of cases resolved before school age. Serial follow-up to establish whether the acquisition of tolerance has occurred is therefore essential in order to avoid unnecessary food restriction and potential consequent nutritional deficiencies. The purpose of this review is to delineate the distinctive clinical features of non-IgE-mediated food allergies presenting with gastrointestinal symptomatology, to summarize our current understanding of the pathogenesis driving these diseases, to discuss recent findings, and to address currents gaps in the knowledge, to guide future management opportunities.

Non-IgE-mediated food hypersensitivity

Non-immunoglobulin E (IgE)-mediated food hypersensitivity includes a spectrum of disorders that predominantly affect the gastrointestinal tract. This review will focus on the following more common non-IgE-mediated food hypersensitivity syndromes: food protein-induced enterocolitis syndrome (FPIES), allergic proctocolitis (AP), food protein-induced enteropathy (FPE) and celiac disease. FPIES, AP and FPE typically present in infancy and are most commonly triggered by cow’s milk protein or soy. The usual presenting features are profuse emesis and dehydration in FPIES; blood-streaked and mucousy stools in AP; and protracted diarrhea with malabsorption in FPE. Since there are no confirmatory noninvasive diagnostic tests for most of these disorders, the diagnosis is based on a convincing history and resolution of symptoms with food avoidance. The mainstay of management for FPIES, AP and FPE is avoidance of the suspected inciting food, with periodic oral food challenges to assess for resolution, which generally occurs in the first few years of life. Celiac disease is an immune-mediated injury caused by the ingestion of gluten that leads to villous atrophy in the small intestine in genetically susceptible individuals. Serologic tests and small intestinal biopsy are required to confirm the diagnosis of celiac disease, and management requires life-long adherence to a strict gluten-free diet.

Non-IgE-mediated Adverse Food Reactions

PURPOSE OF REVIEW

The purpose of this review is to update what is currently known about the major non-IgE-mediated food allergies: food protein-induced enterocolitis syndrome (FPIES), food protein-induced allergic proctocolitis (FPIAP), and food protein-induced enteropathy (FPE). These conditions are similar in that symptoms are regulated to the gastrointestinal tract; therefore understanding their specific features is important for diagnosis and management.

RECENT FINDINGS

The most progress has been made in understanding FPIES with several recent large cohorts being described. The first international consensus guidelines for FPIES were published in 2017 and propose specific diagnostic criteria for acute FPIES as well as guidance for diagnosing chronic FPIES. Recent studies in FPIAP have challenged our thinking about the recommended duration of food avoidance and that cow's milk avoidance is the primary management with reports of self-resolution without dietary management. FPE continues to appear to be on the decline. FPIES, FPIAP, and FPE are distinguished from one another by their main clinical features: delayed repetitive vomiting in FPIES, benign blood in stool in FPIAP, and chronic diarrhea in FPE. Due to the risk of nutritional deficiencies with food avoidance in both infant and maternal diets if breastfeeding, confirmation of diagnosis with challenges is encouraged. Additional studies are needed for these conditions to elucidate pathophysiology, search for diagnostic markers, and understand natural history.

Tolerance development in food protein-induced allergic proctocolitis: Single centre experience

BACKGROUND

Food protein-induced allergic proctocolitis (FPIAP) is characterised by inflammation of the distal colon in response to one or more food proteins. It is a benign condition of bloody stools in a well-appearing infant, with usual onset between one and four weeks of age.

OBJECTIVE

Our objective was to examine the clinical properties of patients with FPIAP, tolerance development time as well as the risk factors that affect tolerance development.

METHODS

The clinical symptoms, offending factors, laboratory findings, methods used in the diagnosis and tolerance development for 77 patients followed in the Paediatric Allergy and Gastroenterology Clinics with the diagnosis of FPIAP during January 2010-January 2015 were examined in our retrospective cross-sectional study.

RESULTS

The starting age of the symptoms was 3.3±4.7 months (0-36). Milk was found as the offending substance for 78% of the patients, milk and egg for 13% and egg for 5%. Mean tolerance development time of the patients was 14.7±11.9 months (3-66 months). Tolerance developed before the age of one year in 40% of the patients. Tolerance developed between the age of 1-2 years in 27%, between the age of 2-3 years in 9% and after the age of 3 years in 5% of the patients.

CONCLUSIONS

Smaller onset age and onset of symptoms during breastfeeding were found associated with early tolerance development. In the majority of the patients, FPIAP resolves before the age of one year, however in some of the patients this duration may be much longer.

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.

Diagnosis of Food Allergy

The prevalence of food allergies has been on the increase over the last 2 decades. Diagnosing food allergies can be complicated, as there are multiple types that have distinct clinical and immunologic features. Food allergies are broadly classified into immunoglobulin E (IgE)-mediated, non-IgE-mediated, or mixed food allergic reactions. This review focuses on the clinical manifestations of the different categories of food allergies and the different tests available to guide the clinician toward an accurate diagnosis.

Food Protein-Induced Non-Immunoglobulin E-Mediated Allergic Colitis in Infants and Older Children: What Cytokines Are Involved?

BACKGROUND

Food protein-induced allergic proctocolitis (FPIAP) is mostly a non-immunoglobulin E-mediated disease where a T-cell-mediated reaction to cow's milk protein has been suggested. We determined the expression of transforming growth factor (TGF)-β, TGF-β receptor-1, tumor necrosis factor (TNF)-α, CD86, and CD23 on the colon mucosa to investigate their roles in the pathogenesis of the two subtypes of FPIAP, i.e. infantile FPIAP and FPIAP in older children.

METHODS

Group 1 comprised children with infantile FPIAP (age <6 months, n = 21), group 2 referred to FPIAP in older children (age >1.5 years, n = 7), and group 3 included children with juvenile hyperplastic polyps (n = 22). Immunohistochemical staining of colonic biopsy specimens was performed.

RESULTS

The expression of TNF-α was significantly higher in groups 1 and 2 compared to group 3. Group 2 patients had a significantly lower TGF-β expression compared to the other groups. The expression of CD86 was higher in group 1 than in group 3 (p = 0.012). Eosinophil counts per high-power field in the lamina propria were significantly correlated with CD86 expression (p = 0.026, r = 0.388).

CONCLUSION

Our results suggest that TNF-α is implicated in the pathogenesis of both types of FPIAP. The decreased activity of TGF-β receptor-1 accompanied by the increased expression of CD86 in infants and the decreased activity of TGF-β in older children appear to play a role in the development of FPIAP.

Food Protein-Induced Enterocolitis Syndrome, Allergic Proctocolitis, and Enteropathy

Food protein-induced enterocolitis (FPIES), allergic proctocolitis (FPIAP), and enteropathy (FPE) are among a number of immune-mediated reactions to food that are thought to occur primarily via non-IgE-mediated pathways. All three are typically present in infancy and are triggered most commonly by cow's milk protein. The usual presenting features are vomiting with lethargy and dehydration in FPIES; bloody and mucous stools in FPIAP; and diarrhea with malabsorption and failure to thrive in FPE. Diagnosis is based on convincing history and resolution of symptoms with food avoidance; confirmatory diagnostic testing other than food challenge is lacking. The mainstay of management is avoidance of the suspected inciting food, with interval challenge to assess for resolution, which usually occurs in the first years of life. Studies published in the past few years clarify common presenting features, report additional culprit foods, address potential biomarkers, and suggest new management strategies.

Non-IgE-mediated gastrointestinal food allergy

Non-IgE-mediated gastrointestinal food-induced allergic disorders (non-IgE-GI-FAs) account for an unknown proportion of food allergies and include food protein-induced enterocolitis syndrome (FPIES), food protein-induced allergic proctocolitis (FPIAP), and food protein-induced enteropathy (FPE). Non-IgE-GI-FAs are separate clinical entities but have many overlapping clinical and histologic features among themselves and with eosinophilic gastroenteropathies. Over the past decade, FPIES has emerged as the most actively studied non-IgE-GI-FA, potentially because of acute and distinct clinical features. FPIAP remains among the common causes of rectal bleeding in infants, while classic infantile FPE is rarely diagnosed. The overall most common allergens are cow's milk and soy; in patients with FPIES, rice and oat are also common. The most prominent clinical features of FPIES are repetitive emesis, pallor, and lethargy; chronic FPIES can lead to failure to thrive. FPIAP manifests with bloody stools in well-appearing young breast-fed or formula-fed infants. Features of FPE are nonbloody diarrhea, malabsorption, protein-losing enteropathy, hypoalbuminemia, and failure to thrive. Non-IgE-GI-FAs have a favorable prognosis; the majority resolve by 1 year in patients with FPIAP, 1 to 3 years in patients with FPE, and 1 to 5 years in patients with FPIES, with significant differences regarding specific foods. There is an urgent need to better define the natural history of FPIES and the pathophysiology of non-IgE-GI-FAs to develop biomarkers and novel therapies.

Outcome of infants presenting rectal bleeding: a retrospective study in a single institution

BACKGROUND

Although rectal bleeding in infancy (RBI) is not a rare phenomenon, the clinical course of RBI is not fully understood.

METHODS

To investigate the outcome and pathogenesis of RBI, especially when concomitant with food-protein-induced proctocolitis (FPIP) and neonatal transient eosinophilic colitis (NTEC), 22 neonates with rectal bleeding with FPIP and NTEC from January 2008 to June 2012 were enrolled and their clinical course and mechanisms of inflammation were examined.

RESULTS

Thirteen infants showed rectal bleeding after feeding and were diagnosed with FPIP, and nine infants showed rectal bleeding before feeding and were diagnosed with NTEC. Elevated peripheral white blood cell (12,685 ± 3754/μl and 30,978 ± 16,166/μl) and eosinophil (1084 ± 816/μl and 4456 ± 3341/μl) were confirmed in FPIP and NTEC, respectively. Colonoscopy revealed nodular lymphoid hyperplasia, a pale mucosal surface and oozing with diffuse infiltration of neutrophils, lymphocytes, and eosinophils in both groups. Reverse transcription polymerase chain reaction analysis revealed enhanced expression of the interleukin-6, CCL11, and CXCL13 genes, where CXCL13 expression was more prominent in FPIP. Mucosal infiltration by CD3- and immunoglobulin-A- but not immunoglobulin-E-positive cells was confirmed. Among them, only one infant with FPIP developed milk allergy, whereas none with NTEC had developed milk allergy at the age of 1 year.

CONCLUSIONS

FPIP in infancy and NTEC are similar diseases and interleukin-6, CCL11, and CXCL13 may play a major role in the pathogenesis of rectal bleeding. Although the involvement of allergic reaction is possible, milk allergy was not a common outcome after 1 year of follow up.

Non-celiac wheat sensitivity as an allergic condition: personal experience and narrative review

OBJECTIVES

Non-celiac wheat sensitivity (NCWS) is a newly described clinical entity characterized by symptoms, which can involve the gastrointestinal tract, the nervous system, the skin, and other organs. There is little data on the pathogenesis of NCWS and it is probable that different pathogenic mechanisms are involved in the different clinical manifestations of the disease. The only common denominator of NCWS "syndrome" is wheat consumption: the symptoms disappear on exclusion of wheat from the diet, and reappear on wheat consumption. The objective of this study was to review our prior data regarding NCWS and to review relevant medical literature regarding NCWS, with particular attention to the hypothesis that NCWS patients could suffer from non-immunoglobulin E (IgE)-mediated wheat allergy.

METHODS

We reviewed our data on 276 patients diagnosed with NCWS by means of double-blind placebo-controlled (DBPC) wheat challenge. The data indicating a possible wheat allergy diagnosis were examined and other data in the literature were reviewed; we review the role of serum immunoglobulin G antibodies and the basophil activation assay in food allergy, and the histology findings in the food allergy diagnosis.

RESULTS

The comparison between patients suffering from NCWS and presenting with irritable bowel syndrome (IBS) and controls with IBS not due to NCWS showed that NCWS was characterized by: a personal history of food allergy in the pediatric age (0.01), coexistent atopic diseases (0.0001), positive serum anti-gliadin (0.0001) and anti-betalactoglobulin (0.001) antibodies, positive cytofluorimetric assay revealing in vitro basophil activation by food antigens (0.0001), and a presence of eosinophils in the intestinal mucosa biopsies (0.0001).

CONCLUSIONS

Patients with NCWS and multiple food sensitivity show several clinical, laboratory, and histological characteristics that suggest they might be suffering from non-IgE-mediated food allergy. However, other pathogenic mechanisms need to be considered.

Gastrointestinal food allergy in infants

Food allergies are classified into three types, "IgE-mediated," "combined IgE- and cell-mediated" and "cell-mediated/non-IgE-mediated," depending on the involvement of IgE in their pathogenesis. Patients who develop predominantly cutaneous and/or respiratory symptoms belong to the IgE-mediated food allergy type. On the other hand, patients with gastrointestinal food allergy (GI allergy) usually develop gastrointestinal symptoms several hours after ingestion of offending foods; they belong to the cell-mediated/non-IgE-mediated or combined IgE- and cell-mediated food allergy types. GI allergies are also classified into a number of different clinical entities: food protein-induced enterocolitis syndrome (FPIES), food protein-induced proctocolitis (FPIP), food protein-induced enteropathy (Enteropathy) and eosinophilic gastrointestinal disorders (EGID). In the case of IgE-mediated food allergy, the diagnostic approaches and pathogenic mechanisms are well characterized. In contrast, the diagnostic approaches and pathogenic mechanisms of GI allergy remain mostly unclear. In this review, we summarized each type of GI allergy in regard to its historical background and updated clinical features, offending foods, etiology, diagnosis, examinations, treatment and pathogenesis. There are still many problems, especially in regard to the diagnostic approaches for GI allergy, that are closely associated with the definition of each disease. In addition, there are a number of unresolved issues regarding the pathogenic mechanisms of GI allergy that need further study and elucidation. Therefore, we discussed some of the diagnostic and research issues for GI allergy that need further investigation.

Characteristics of allergic colitis in breast-fed infants in the absence of cow’s milk allergy

AIM: To investigate the characteristics of mucosal lesions and their relation to laboratory data and long-term follow up in breast-fed infants with allergic colitis.

METHODS: In this study 31 breast-fed infants were prospectively evaluated (mean age, 17.4 wk) whose rectal bleeding had not ceased after a maternal elimination diet for cow’s milk. Thirty-four age-matched and breast-fed infants (mean age, 16.9 wk) with no rectal bleeding were enrolled for laboratory testing as controls. Laboratory findings, colonoscopic and histological characteristics were prospectively evaluated in infants with rectal bleeding. Long-term follow-up with different nutritional regimes (L-amino-acid based formula or breastfeeding) was also included.

RESULTS: Iron deficiency, peripheral eosinophilia and thrombocytosis were significantly higher in patients with allergic colitis in comparison to controls (8.4 ± 3.2 μmol/L vs 13.7 ± 4.7 μmol/L, P < 0.001; 0.67 ± 0.49 G/L vs 0.33 ± 0.17 G/L, P < 0.001; 474 ± 123 G/L vs 376 ± 89 G/L, P < 0.001, respectively). At colonoscopy, lymphonodular hyperplasia or aphthous ulceration were present in 83% of patients. Twenty-two patients were given L-amino acid-based formula and 8 continued the previous feeding. Time to cessation of rectal bleeding was shorter in the special formula feeding group (mean, 1.4 wk; range, 0.5-3 wk) when compared with the breast-feeding group (mean, 5.3 wk; range, 2-9 wk). Nevertheless, none of the patients exhibited rectal bleeding at the 3-mo visit irrespective of the type of feeding. Peripheral eosinophilia and cessation of rectal bleeding after administration of elemental formula correlated with a higher density of mucosal eosinophils.

CONCLUSION: Infant hematochezia, after cow’s milk allergy exclusion, is generally a benign and probably self-limiting disorder despite marked mucosal abnormality. Formula feeding results in shorter time to cessation of rectal bleeding; however, breast-feeding should not be discouraged in long-lasting hematochezia.

Recognition and management of pediatric food allergy in the emergency department

Recently, the National Institute of Allergy and Infectious Diseases sought to establish consistency in definitions, diagnostic criteria, and management practices concerning food allergies (FAs). This review aimed to summarize and highlight the relevant findings of these guidelines for the emergency department provider, as pediatric patients often present to the emergency department with FAs or other disorders mimicking FAs.

Molecular mechanisms of IgE mediated food allergy

The purpose of this review is to collate current knowledge and recent advances in molecular mechanism behind the immediate type hypersensitivity of foods. Food allergy is a growing concern of human health in developed as well as developing countries now days. Food allergic reactions are mostly IgE mediated and also known as immediate type hypersensitivity or type I reaction. This review encompasses a wide range of molecular events during IgE mediated reactions like primary exposure of allergens, processing of allergens by antigen presenting cells, role of transcription factors like GATA-3, STAT-6, NF-AT, c-maf, c-kit and NF-κB, Treg cells, toll like receptors, cytokines and chemokines, class switch to IgE, FcεR1 receptor, priming of IgE on mast cells or basophils, signaling events followed by secondary exposure of allergens, degranulation and release of mediators like leukotrienes, histamines, prostaglandins, β-hexosaminidase and ultimately anaphylaxis. This review may be helpful to beginners as well as experts working in the field of allergy and immunology because of the stepwise explanations of molecular mechanisms involved in IgE mediated reactions.

Food allergy

Food allergy appears to be increasing in prevalence and is estimated to affect >2% and possibly up to 10% of the population. Food allergies are defined by an immune response triggered by food proteins. Emerging data suggest that carbohydrate moieties on food proteins, specifically mammalian meats, may also elicit allergic responses. Food is the most common trigger of anaphylaxis in the community, which can be fatal. The underlying mechanisms of food allergy usually involve food-specific immunoglobulin E antibodies, but cell-mediated disorders account for a variety of chronic or subacute skin and gastrointestinal reactions. Eosinophilic esophagitis is an emerging food-related chronic disorder. The diagnosis of food allergy is complicated by the observation that detection of food-specific immunoglobulin E (sensitization) does not necessarily indicate clinical allergy. Diagnosis requires a careful medical history, laboratory studies, and, in many cases, oral food challenges to confirm a diagnosis. Novel diagnostic methods, many of which rely upon evaluating immune responses to specific food proteins or epitopes, may improve diagnosis and prognosis in the future. Current management relies upon allergen avoidance and preparation to promptly treat severe reactions with epinephrine. Studies suggest that some children with milk or egg allergy might tolerate extensively heated forms, for example milk or egg baked into muffins, without symptoms and possibly with some immunotherapeutic benefits. Novel therapeutic strategies are under study, including oral and sublingual immunotherapy, Chinese herbal medicine, anti-immunoglobulin E antibodies, and modified vaccines.

Clinical presentations of food allergy

Food allergies are immune-mediated responses to food proteins. Because of differences in the underlying immunologic mechanisms, there are varying clinical presentations of food allergy. This article discusses the manifestations of IgE-mediated disorders, including urticaria and angioedema, rhinoconjunctivitis, asthma, gastrointestinal anaphylaxis, generalized anaphylaxis, food-dependent exercise-induced anaphylaxis, and oral allergy syndrome. It also reviews the presentations of mixed IgE- and cell-mediated disorders, including atopic dermatitis and eosinophilic gastrointestinal disorders. Finally, the manifestations of cell-mediated food allergies are discussed, including dietary protein-induced proctitis and proctocolitis, food protein-induced enterocolitis syndrome, celiac disease, and food-induced pulmonary hemosiderosis.

Regulatory T cells and T helper subsets in breast-fed infants with hematochezia caused by allergic colitis

The objective of our study was to investigate the prevalence of CD4 T lymphocyte subsets and their commitment to TH1 or TH2 direction in 10 infants with allergic colitis (AC) and 10 healthy controls. Infants with AC presented with a higher ratio of naïve to memory cells, lower prevalence of activated CD4CD25 cells and FoxP3 regulatory cells, and a shift to TH2 direction in balance compared with controls. These alterations are normalized upon cessation of AC symptoms on elemental L-amino acid formula. These findings suggest the importance of antigen exposure in AC in infancy.

A Review of Food Allergy and Nutritional Considerations in the Food-Allergic Adult

In the United States, the prevalence of adults with food allergies is approximately 2% to 3%. Theoretically, any food can cause an allergic reaction; however, some foods are clearly more allergenic than others. In adults, peanuts, tree nuts, finned fish, crustaceans, fruit, and vegetables account for 85% of the food-allergic reactions. Currently, the only ways to manage food allergies are to avoid the allergen and initiate therapy for an allergic reaction if ingestion does occur. The presence of homologous proteins among animal or plant foods and between foods and certain airborne allergens may account for cross-sensitization that may be clinically relevant. For inpatients or outpatients with food allergies, nutrient and fluid requirements are the same as for individuals without food allergies. Since patients with adverse reactions to food may self-restrict intake or have been counseled on food avoidance, it is particularly important to determine dietary adequacy and to provide patients with appropriate food substitutions to provide nutrients that may be missing from a patient’s diet. This is of particular concern for individuals with multiple food allergies. Eating away from home and traveling also pose special problems for those with food allergies.

Childhood constipation and diet

Constipation is a common problem in children. However, there is much controversy surrounding the etiology, diagnosis and treatment of functional constipation observed in childhood. Despite the high frequency of this problem documented in the literature, there is little research that assesses the direct relationship between the food consumed and the eventual stool consistency. Breastfeeding is an excellent way to prevent constipation in infants and toddlers, as is fruit and vegetable consumption in older children. The aim of this review is to investigate available tools in the literature concerning constipation in children and to discuss the relationship between constipation and diet in childhood.

Colon in food allergy

The colon is a site of allergic reaction to food proteins. The most common manifestation is allergic proctocolitis. Although frequent in infancy, it may also affect older children. The diagnosis of allergic proctocolitis is mainly based on clinical and histological grounds, but there is a risk of overdiagnosis; challenge is strongly recommended to avoid unnecessary and expensive formula or changes in maternal diet that may discourage continuation of breast-feeding. The benign clinical course and the spontaneous resolution in most infants suggest the need for further prospective studies to validate markers that allow the identification of those children needing a dietary approach. It remains to be assessed whether lymphoid nodular hyperplasia of the colon is a manifestation of food allergy. Finally, allergic proctitis may present clinically with refractory constipation; the true prevalence of food allergy-related constipation remains to be assessed.

Colonic left-side increase of eosinophils: a clue to drug-related colitis in adults

BACKGROUND

The colon shows frequent eosinophilic infiltration in allergic proctocolitis of infants, whereas in adults, eosinophilic infiltration of the colon is less defined and may be found in different conditions including drug-induced colitis, even though the pathological findings are often inconsistent.

AIM

To quantify eosinophils in the mucosa of normal controls and to compare them with those of patients with abdominal symptoms related to 'drug colitis'.

METHODS

Mucosal biopsies were obtained during colonoscopy in 15 controls and in 27 patients with abdominal symptoms, a history of probable 'drug-related colitis' and without obvious causes of eosinophilia.

RESULTS

The drugs related to the patient symptoms were nonsteroidal anti-inflammatory drugs (70%), antiplatelet agents (19%) and oestroprogestinic agents (11%). Colonoscopy was normal in 30% of patients and abnormal in 70%. Histology showed low content of inflammatory cells and normal crypt architecture in-patients with endoscopy similar to inflammatory bowel diseases. The eosinophil score was significantly higher in the left side of the colon in the patient group compared with controls.

CONCLUSIONS

The finding of an increased eosinophil count limited to the left (descending and sigmoid) colon is an important clue towards a diagnosis of drug-related colitis.