Differential diagnosis of food protein-induced enterocolitis syndrome

Severe Food Protein-Induced Enterocolitis Syndrome After Hematopoietic Stem Cell Transplantation: Pediatric Case Report

BACKGROUND

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated food allergy. In the last few years, after the publication of the consensus guidelines, with refined diagnostic criteria and improved awareness, FPIES is diagnosed with increased frequency. However, despite having a background of immune dysregulation, this complication has just been described once in the posttransplant setting, in an adult patient. To the best of our knowledge, there are no reports of pediatric patients developing FPIES after a hematopoietic stem cell transplant (HCT).

METHODS

Retrospective review of a pediatric patient who developed severe FPIEs after a HCT.

RESULTS

In this case report, the clinical presentation and diagnosis challenges of a pediatric patient who developed severe FPIES after HCT are described. The patient developed severe vomiting, diarrhea, lethargy, and shock and required admission to the pediatric intensive care unit in three occasions before the diagnosis was made.

CONCLUSIONS

To the best of our knowledge, this is the first report of severe FPIES post-HCT in a pediatric patient. Physicians who are looking after pediatric patients in the post-HCT setting need to be aware of this possibility and include this entity in the differential diagnosis in order to reduce its associated morbidity.

[Differential diagnosis in food allergy]

It is important to establish the differential diagnosis of food allergy with other disorders, for example: toxic reactions that occur in any person exposed to a sufficient amount of some allergen, and non-toxic reactions that depend on individual susceptibility (food allergy or intolerance). The differential diagnosis is decisive to establish the appropriate treatment. Food intolerance involves adverse reactions to foods without any immunological response involved, and commonly manifests with gastrointestinal symptoms (malaise, abdominal pain or diarrhea). Food allergy is an exaggerated reaction of the immune system, often mediated by IgE, that can trigger serious symptoms (hives, inflammation, respiratory distress, even anaphylaxis). The complex thing is because the symptoms sometimes overlap. To establish an accurate diagnosis, exhaustive clinical evaluation, laboratory tests and, in some cases, controlled provocation tests are required. It is important to understand these distinctions, because treatment and management vary significantly. Food intolerance involves the elimination or reduction of the food that triggers the allergic reaction and requires rigorous measures (complete avoidance of the allergen and availability of epinephrine in cases of severe reactions).

Diagnostic and Management Strategies of Food Protein-Induced Enterocolitis Syndrome: Current Perspectives

Food protein-induced enterocolitis syndrome (FPIES) is a form of non-IgE mediated food allergy that presents with delayed gastrointestinal symptoms after ingestion of the trigger food. The data regarding FPIES are sparse, despite being recognized as a distinct clinical entity. This narrative review presents the characteristics of this disorder in the pediatric population, as well-standard diagnostic and management protocols. FPIES can be classified into acute and chronic subtypes, and some cases may develop into an IgE-mediated allergy. Given that skin prick tests and specific IgE levels are negative in the majority of cases, diagnosis relies on clinical history and oral food challenges. Management involves elimination diets, assessment of tolerance through oral food challenges, and rehydration in the event of a reaction. Future research should focus on improving diagnostic methods, illustrating underlying pathogenesis and biomarkers, and assessing long-term natural history. Increased knowledge and awareness for FPIES are required.

Assessment of intracellular zinc levels in infants with food protein-induced allergic proctocolitis

BACKGROUND

Food protein-induced allergic proctocolitis (FPIAP) is characterized by bloody stools in well-appearing infants. Zinc is a micronutrient that plays a crucial role in immune modulation and is essential for cellular function during immune response. Although there are studies on the assessment of intracellular zinc levels in allergic diseases, no data is available on erythrocyte zinc levels of patients with FPIAP.

OBJECTIVE

This study aimed to assess the erythrocyte zinc levels of children with allergic proctocolitis and compare zinc levels with clinical and demographic characteristics.

METHODS

This was a case-control study that prospectively compared 50 patients with FPIAP and 50 healthy children without malnutrition. The erythrocyte zinc levels of children were determined using atomic absorption spectrophotometry.

RESULTS

Fifty patients with FPIAP, including 28 (51%) girls, with median age of 7.1 ± 2.9 (3-14) months and 50 healthy children, including 26 (53.1%) girls, with median age of 7.7 ± 2.8 (3-13) months were included in the study. Seventy percent (n = 35) of the patients with FPIAP started to have symptoms while they were exclusively breastfeeding. Offending allergen foods were cow's milk (78%), egg (40%), sesame (10%), hazelnut (8%), almond (6%), beef (6%), and peanuts (6%, n = 3). Intracellular (erythrocyte) zinc levels in patients with FPIAP were lower than in the healthy control group (495.5 ± 134 µg/dL, 567.3 ± 154.4 µg/dL, respectively, P = 0.01). Patients with FPIAP aged younger than 6 months had lower intracellular zinc levels compared with those aged above 6 months (457 ± 137 µg/dL; 548 ± 112 µg/dL, respectively, P = 0.01). There was no relationship between zinc levels and time of symptom onset, presence of concomitant disease, being allergic to multiple foods, and family history of atopy (P > 0.05).

CONCLUSIONS

FPIAP is a food allergy with limited information on its pathogenesis. Considering the beneficial effects on gastrointestinal system epithelia, zinc may be involved in the pathogenesis of FPIAP. Future comprehensive prospective research on this subject is of importance.

Food Protein-Induced Enterocolitis Syndrome Causing Hypovolemic Shock in Infants With Down Syndrome

This study aimed to investigate the clinical characteristics of severe food protein-induced enterocolitis syndrome (FPIES) in patients with Down syndrome. We report the cases of three infants with Down syndrome who were diagnosed with FPIES. All patients presented with hypovolemic shock, metabolic acidosis, and acute kidney injury after introducing a milk-based formula. They required aggressive fluid resuscitation and alternative nutrition. All three patients survived without any complications after the treatment. FPIES may cause hypovolemic shock in infants with Down syndrome and these patients need prompt fluid resuscitation.

Differentiation of food protein-induced enterocolitis syndrome misleading to necrotizing enterocolitis

BACKGROUND

Food protein-induced enterocolitis syndrome (FPIES) is a rare non-immunoglobulin E-mediated food allergy with necrotizing enterocolitis (NEC)-like symptoms which requires differential diagnosis as treatments differ.

OBJECTIVE

To evaluate the clinical, laboratory, and radiologic findings that differentiate FPIES from NEC in preterm and term infants.

METHODS

Clinical features, comorbidities, and laboratory and radiologic findings of neonates with presumed NEC were reviewed retrospectively and compared between FPIES and NEC in preterm and term infants who were admitted to the neonatal intensive care unit at Seoul National University Bundang Hospital between May 2003 and February 2020.

RESULTS

A total of 10 of 150 (6.7%) preterm and 17 of 38 (44.7%) term infants with presumed NEC were confirmed to have FPIES; the remainder had NEC by modified Bell's criteria. Demographics and comorbidities were similar between these groups. Symptoms such as hematochezia, shock, leukocytosis, peripheral eosinophilia, and feeding of extensively hydrolyzed milk formula or elemental formula after discharge were significantly different between the 2 groups in term infants (P <.05), but not in preterm infants. On abdominal ultrasonography, pneumatosis intestinalis was more common among preterm FPIES (44.4%) than NEC cases (21.6%) (P =.04). Among the preterm infants, 4 FPIES (40%) and 25 NEC (17.9%) cases required surgery (P =.10).

CONCLUSION

Differentiating FPIES in neonates suspected of having NEC is important as dietary elimination of the triggering milk protein can be recommended instead of prolonged fasting and antibiotic treatment, which are indicated for NEC, in both term and preterm infants.

Cow's milk allergy non-responsive to amino acid-based formula? A successful transplanted patient with immune dysregulation, polyendocrinopathy, enteropathy, and X-linked syndrome

The wide variety of IPEX symptoms leads to diagnosis and treatment delay with fatal outcomes if left untreated before two first years of life. Cow's milk allergy non-responsive to amino acid-based formula must raise suspicion of this syndrome.

Epidemiology of non-IgE-mediated food allergies: what can we learn from that?

PURPOSE OF REVIEW

To underline the main characteristics of the non-Immunoglobulin E (IgE)-mediated food allergies (food protein-induced allergic proctocolitis food protein-induced enteropathy and food protein-induced enterocolitis syndrome ), which are common diseases in primary care and in allergy and gastroenterology specialty practices evaluating children.

RECENT FINDINGS

Non-IgE-mediated food allergies comprise a spectrum of diseases with peculiar features affecting infants and young children. The most prominent features of these diseases are symptoms that affect mainly the gastrointestinal tract.

SUMMARY

It is of paramount importance to provide the clinicians with the tools for non-IgE-mediated food allergy recognition in clinical practice to avoid the misdiagnosis with unnecessary laboratory tests and detrimental treatments.

'Diagnosing food protein-induced enterocolitis syndrome'

Food protein-induced enterocolitis syndrome is still a mysterious disease, pathogenically poorly characterized, although the first FPIES case has been described in 1967. Mainly, food protein-induced enterocolitis syndrome diagnosis is based on clinical history. The oral food challenge remains the gold standard to confirm the diagnosis, especially in particular situations. Although there are no diagnostic laboratory or imaging tests which are specific for diagnosis, they could, however, sometimes be helpful to rule out clinical conditions which are similar to food protein-induced enterocolitis syndrome reactions. The purpose of this review is to define the clinical features of FPIES and to summarize the current available tools for the diagnosis of FPIES. This review is intended to be a practical guide for the clinician facing a patient with food protein-induced enterocolitis syndrome avoiding delayed diagnosis with unnecessary laboratory tests and detrimental treatments. Moreover, it highlights the unmet needs in diagnosis that require urgent attention from the scientific community to improve the management of patients with FPIES.

Early onset food protein-induced enterocolitis syndrome in two breastfed newborns masquerading as surgical diseases: case reports and literature review

Background: Food protein-induced enterocolitis syndrome (FPIES) is a non-immunoglobulin E cell-mediated gastrointestinal food allergy that primarily presents in infancy, as early as the first hours of life. FPIES is often misdiagnosed as sepsis, severe gastroenteritis, abdominal surgical emergency or even metabolic, neurologic, or cardiac disorders.Methods: We report two neonatal cases of cow's milk protein (CMP)-induced FPIES masquerading as surgical diseases. Our purpose is to highlight the diagnostic difficulties in FPIES in this age group and to provide further evidence of the important role played by the prenatal environment in the development of allergic diseases.Results: Case 1 is a 2-day-old boy born at 35th + 5 weeks of gestation admitted to our Neonatal Intensive Care Unit (NICU) for bloody diarrhea who started presenting apnea, crying, pallor, jaundice, and abdominal tenderness. Case 2 is a 3-day-old boy born at 38th +5 weeks of gestation admitted to our NICU for repeated bilious vomiting. Both patients were administered infant formula in the first hours of life, thereafter they received only breast milk. In both cases, CMP allergy was finally suspected and an extensively hydrolyzed formula was administered with the resolution of symptoms. A diagnosis of CMP-induced FPIES was made.Conclusions: FPIES is a heterogeneous disorder. Severe forms of FPIES could be mistaken for surgical diseases, such as necrotizing enterocolitis. A trial of food elimination should be considered whenever diagnostic tests are inconclusive. FPIES must be suspected even in breastfed infants.

[Food protein-induced enterocolitis syndrome (FPIES) - a rare disease with frequent symptoms - the practitioner's compendium]

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated food allergy with varying degrees of severity. The acute form of the disease is manifested by vomiting, lethargy and pallor, which usually appear within 1-4 hours after food ingestion, and can lead to shock. The most common trigger foods are: cow's milk, soy, rice and oats. Chronic FPIES is typical for infants fed with cow's milk or soy infant formula and is manifested by chronic vomiting, diarrhea and failure to thrive. In the vast majority of patients with FPIES, the analysis of the clinical history is sufficient to diagnose and identify trigger foods. If the history is unclear, use an oral food challenge to help confirm the diagnosis. Long-term management of patients with FPIES involves elimination of the trigger foods, monitoring for FPIES resolution and caregivers' education. The majority of children acquire food tolerance at the age of 3-5.

Severely Altered-Consciousness Status and Profuse Vomiting in Infants: Food Protein-Induced Enterocolitis Syndrome (FPIES), a Challenging Diagnosis

In infants, the causes of acute repetitive vomiting and severely altered-consciousness status include a broad differential diagnosis, that is, primarly sepsis, infectious gastroenteritis, head injury, and intoxication, as well as neurologic, metabolic, and cardiologic condition diseases. In patients developing such symptoms, allergy as an etiological cause is often not considered by primary care physicians. With this case report, we aim to draw the attention of general pediatricians, emergency physicians, and intensivists to the fact that non-immunoglobulin E-mediated food allergic gastrointestinal disorders such as food protein-induced enterocolitis syndrome should be considered in patients with sepsis-like symptoms.

Food Protein-Induced Enterocolitis Syndrome (FPIES): Review of Recent Guidelines

PURPOSE OF REVIEW

To increase understanding of food protein-induced enterocolitis syndrome (FPIES), a non-immunoglobulin E (IgE)-mediated reaction to food, by reviewing a growing body of literature, including recently published international consensus guidelines.

RECENT FINDINGS

FPIES primarily affects infants and young children and is characterized by the delayed onset of gastrointestinal symptoms, predominantly repetitive vomiting, in response to a trigger food. Symptoms are often severe and can lead to shock. Diagnosis can be challenging due to a wide differential diagnoses and lack of disease biomarkers. FPIES is a clinical diagnosis, with allergy testing playing a very limited role, if any. Medically supervised oral food challenges are used to monitor resolution of disease, which generally occurs in early childhood. FPIES is an important condition presenting to clinicians in a variety of settings. Recent international consensus guidelines and a growing body of literature can better equip practitioners to care for these often-challenging patients.

Allergic gastroenteritis hospital admission time trends in Australia and New Zealand

AIM

Recent epidemiological studies indicate increases in hospital food allergy-related anaphylaxis admission rates in Australian and New Zealand. The aim of the study was to examine whether non-IgE-mediated food allergy might have increased in parallel.

METHODS

We analysed childhood hospital admissions rates by ICD 10 codes for allergic gastroenteritis (AG) and infective gastroenteritis in Australia and New Zealand between June 1998 and July 2014.

RESULTS

In Australia, most AG-related admissions (73%) occurred in those aged <1 year and increased by 7.3%/year (95% confidence interval (CI) 5.5-9.3, P < 0.0001) from 6.8 to 26.5/10⁵ population. Similar trends were observed for New Zealand; 81% of admissions occurred in those aged <1 year and increased by 9.4%/year (95% CI 5.5-9.3, P < 0.0001) from 7.2 to 30.7/10⁵ population. By contrast there were no significant changes in AG-related admission rates in the older patients and infective gastroenteritis admissions fell in both countries in those aged <1 year; Australia by 4.4%/year (95% CI 4.3-4.6, P < 0.0001) and in New Zealand by 5.8%/year (95% CI 5.4-6.2, P < 0.0001).

CONCLUSION

We observed a fourfold increase in AG-related admission rates in two countries with known high rates of IgE-mediated food allergy/anaphylaxis. If confirmed by other studies, it will be of interest to determine if factors thought to contribute to the increase in IgE-mediated food allergy might also play a role in non-IgE-mediated gastroenterological food allergy syndromes.

Inflammatory events during food protein-induced enterocolitis syndrome reactions

BACKGROUND

An increasing number of infants are diagnosed with food protein-induced enterocolitis syndrome (FPIES), a non-IgE-mediated food allergy. Until now, T-cell, food-specific mechanisms have been hypothesized.

METHODS

Sixteen children (11M, 5F), affected by FPIES from cow's milk, wheat, fruit, rice, and others, experienced 25 acute episodes managed at our emergency department (ED) and eight FPIES reactions during oral food challenges (OFC). We compared the laboratory data in resting conditions, in the absence of infectious diseases, with data collected during the 25 acute ED episodes (blood samples drawn at 2-12 hours) and the eight positive OFCs (three samples at 2, 6, and 12 hours). The onset of symptoms was used as a reference time point.

RESULTS

In basal conditions, total IgE, WBC, neutrophil and eosinophil count, CRP, and SGPT were found normal. LDH and SGOT values were high (627.81±97.88 and 45.75±10.26 UI/L, respectively). During ED reactions, LDH and SGOT increased to 794.21±247.28 (P=.028) and 51.08±16.99 UI/L (P=.14) and neutrophils count and CRP to 8.44±3.82×10³ /μL (P=.0009) and 3.27±5.73 mg/dL (P=.0014), respectively. During positive OFC, LDH and SGOT did not vary significantly; CRP increased from 0.14±0.18 to 2.49±3.65 mg/dL (P=.00189) and neutrophil count from 2.79±1.42 to 7.10±3.98×10³ /μL (P=.00096).

CONCLUSIONS

FPIES reactions are characterized by neutrophilia and by a time-dependent, significant increase in CRP, indicating that inflammatory mechanisms are in place. This suggests new directions for research on FPIES pathogenesis.

Trends in Provider Management of Patients with Food Protein-Induced Enterocolitis Syndrome

BACKGROUND

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated food allergy.

OBJECTIVE

To better understand provider-level variation in FPIES knowledge and management.

METHODS

A 23-question online survey was administered to AAAAI members during the spring and summer of 2014.

RESULTS

Among 470 respondents, 64% reported "full understanding" of FPIES diagnosis/management; 78.8% reported managing 1 or more patient with FPIES; and 80.4% correctly identified an FPIES case vignette. FPIES was correctly differentiated from infantile colic or food protein-induced allergic proctocolitis by 82.5% and 71.3%, respectively. Among providers currently managing patients with FPIES, 47.5% indicated soy formula, 73.8% breast milk, and 94.5% elemental formula as appropriate substitutes in cow milk (CM)-FPIES. Skin testing is performed by 73.4%; 62.2% obtain serum food-specific IgE testing, 12.7% patch testing, 36.8% oral challenge, and 28% perform no tests. Eighty-four percent provide patients with FPIES with allergy action plans, 72.8% provide a personalized action plan, and 21% prescribe epinephrine autoinjectors. Odds of prescribing epinephrine were lower among those reporting "full understanding" of FPIES (odds ratio [OR], 0.41; 95% CI, 0.21-0.79). Academic providers had higher odds of providing an action plan (OR, 2.4; 95% CI, 1.17-4.98) and performing diagnostic oral food challenge (OR, 1.99; 95% CI, 1.99-3.25), but not of correct vignette differentiation of FPIES from other conditions, correct identification of appropriate CM-FPIES substitutes, or timing for food reintroduction. More years in practice were associated with lower odds of reporting full understanding of FPIES diagnosis/management (OR, 0.96; 95% CI, 0.94-0.99).

CONCLUSIONS

Nearly one-third of respondents reported poor familiarity with FPIES. Considerable variation exists in the use of diagnostic tests, management, and choice of "safe" nutrition, indicating a strong need for FPIES practice guidelines.

Awareness of allergic enterocolitis among primary-care paediatricians: A web-based pilot survey

BACKGROUND

Allergic enterocolitis, also known as food protein-induced enterocolitis syndrome (FPIES), is an increasingly reported and potentially severe non-IgE mediated food allergy of the first years of life, which is often misdiagnosed due to its non-specific presenting symptoms and lack of diagnostic guidelines.

OBJECTIVE

We sought to determine the knowledge of clinical, diagnostic and therapeutic features of FPIES among Italian primary-care paediatricians.

METHODS

A 16-question anonymous web-based survey was sent via email to randomly selected primary care paediatricians working in the north of Italy.

RESULTS

There were 194 completed surveys (48.5% response rate). Among respondents, 12.4% declared full understanding of FPIES, 49% limited knowledge, 31.4% had simply heard about FPIES and 7.2% had never heard about it. When presented with clinical anecdotes, 54.1% recognised acute FPIES and 12.9% recognised all chronic FPIES, whereas 10.3% misdiagnosed FPIES as allergic proctocolitis or infantile colic. To diagnose FPIES 55.7% declared to need negative skin prick test or specific-IgE to the trigger food, whereas 56.7% considered necessary a confirmatory oral challenge. Epinephrine was considered the mainstay in treating acute FPIES by 25.8% of respondents. Only 59.8% referred out to an allergist for the long-term reintroduction of the culprit food. Overall, 20.1% reported to care children with FPIES in their practice, with cow's milk formula and fish being the most common triggers; the diagnosis was self-made by the participant in 38.5% of these cases and by an allergist in 48.7%.

CONCLUSION

There is a need for promoting awareness of FPIES to minimise delay in diagnosis and unnecessary diagnostic and therapeutic interventions.

DMP1-CDG (CDG1e) with Significant Gastrointestinal Manifestations; Phenotype and Genotype Expansion

The literature describes eight cases of mutations in the DPM1 gene generating DMP1-CDG, causing similar phenotype of early onset seizures, microcephaly and developmental delay. Investigations of these patients revealed associated abnormal findings on brain imaging, elevated CK, abnormal clotting factors and mildly deranged serum transaminases. We describe the ninth case of DMP1-CDG, whose clinical presentation includes severe gastrointestinal involvement, i.e. food protein induced enterocolitis syndrome (FPIES). Gastrointestinal manifestations (GIT) of the congenital glycosylation disorders have included deranged liver function, hepatomegaly, liver fibrosis, steatosis and protein-losing enteropathy. This is the first report of a congenital glycosylation disorder being associated with FPIES.

FPIES: Reviewing the Management of Food Protein-Induced Enterocolitis Syndrome

Purpose of Review. The aim of this review is to provide a case driven presentation of the presenting features and diagnostic criteria particularly focusing on the management of FPIES. It also summarises the natural history and resolution of cow's milk induced FPIES. Data Sources. OvidSP Database was used to search for literature using the keywords food protein-induced enterocolitis and FPIES. Recent Findings. The diagnosis of FPIES is often delayed following two or more presentations. Symptoms in the acute form include profuse vomiting usually 2–6 hours following ingestion of food. Vomiting may or may not be accompanied by diarrhoea. Management involves removing the causal food protein from diet. There is some concomitance in cow's milk and soya induced FPIES. Hence extensively hydrolysed formula is the milk of choice unless breast-feeding is carried out in which case that should be continued. Summary. FPIES is a complex form of non-IgE mediated food allergy. More awareness and knowledge of the condition are required to prevent misdiagnosis. Early diagnosis and removal of the culprit food protein improve the outcome. Good nutritional advice and clear management plans are important. More multicentre studies are required to reevaluate and produce consistent oral food challenge criteria and guidelines.

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.

High Prevalence of Neutrophil Cytoplasmic Autoantibodies in Infants with Food Protein-Induced Proctitis/Proctocolitis: Autoimmunity Involvement?

Background. Food protein-induced proctitis/proctocolitis (FPIP) is the most common noninfectious colitis in children in the first year of life. Along with the overall clinical symptoms, diarrhoea and rectal bleeding are the main manifestations of the disease. There is no routine noninvasive test that would be specific for this type of colitis. The aim of our study was to find a noninvasive laboratory test or tests that may be helpful in differential diagnosis of food protein-induced proctitis/proctocolitis. Methods. ANA, ANCA, ASCA, a-EMA, a-tTg, specific IgE, total IgE, IgG, IgA, IgM, and concentration of serum calprotectin were measured in a group of 25 patients with colitis and 18 children with other diagnoses. Results. Atypical-pANCA antibodies of IgG isotype were detected in the sera of 24 patients by the method of indirect immunofluorescence, and 5 patients showed also the positivity of IgA isotype. In control samples these autoantibodies were not detected. Other autoantibodies were not demonstrated in either patient or control group. Conclusions. Of the parameters tested in noninfectious colitis, atypical-pANCA on ethanol-fixed granulocytes appears to be a suitable serological marker of food protein-induced proctitis/proctocolitis and suggests a possible involvement of an autoimmune mechanisms in the pathogenesis of this disease.

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.

Definition, etiology, and diagnosis of food protein-induced enterocolitis syndrome

PURPOSE OF REVIEW

Food protein-induced enterocolitis syndrome (FPIES) is a poorly understood non-IgE-mediated food hypersensitivity, primarily affecting infants and toddlers. There are few data regarding pathophysiology of FPIES that suggest local intestinal imbalance between TNF-α and TGF-β. Patients frequently present with multiple reactions, which are characterized by projectile, repetitive emesis, dehydration, lethargy, and failure to thrive. Despite the severity of presentation, the diagnosis is frequently delayed, and patients often undergo extensive and invasive evaluation prior to reaching the diagnosis.

RECENT FINDINGS

Reviews published in the last year provide a general approach to diagnosis and management of FPIES and aim to increase awareness and understanding of FPIES among general pediatricians.

SUMMARY

Multicenter studies are necessary to reevaluate and modify the oral food challenge criteria. Research on the pathophysiology of FPIES reactions is necessary to provide insight into the evidence-based approach to diagnosis and management of FPIES. Registries are needed to understand the phenotype, triggers, and prevalence of FPIES.