Increased C-reactive protein and fever in Japanese infants with food protein-induced enterocolitis syndrome

Clinical-Hematological Changes and Predictors of Severity in Acute Food Protein-Induced Enterocolitis Syndrome Reactions at Oral Food Challenge: A Multicenter Observational Study

BACKGROUND

Oral food challenge (OFC) is the criterion standard for diagnosis of acute food protein-induced enterocolitis syndrome (FPIES). No diagnostic/prognostic biomarkers are available, and OFC assessment criteria are not validated.

OBJECTIVE

To assess clinical-hematological changes and predictors of severity of FPIES reactions at OFC.

METHODS

This was an observational multicenter prospective study. Children aged 0 to 18 years diagnosed with acute FPIES were recruited at follow-up OFC in 12 tertiary centers in Spain and Italy. OFC outcomes (as positive/negative/inconclusive and mild/moderate/severe) were assessed on the basis of published "2017 FPIES Consensus" criteria. Clinical characteristics were recorded, and full blood cell count was done at baseline, reaction onset, and 4 hours later. Regression analysis was performed to assess predictors of severe reactions at OFC.

RESULTS

A total of 81 children had positive OFC (mild in 11% [9 of 81], moderate in 61% [49 of 81], and severe in 28% [23 of 81]). Increase in neutrophils and reduction in eosinophils, basophils, and lymphocytes were observed (P < .05). OFC was inconclusive in 19 cases despite objective signs or neutrophilia. Regression analysis showed that a 2-day OFC protocol where only 25% of an age-appropriate portion is given on day 1 (not sex, age, culprit food, cumulative dose, and previous reaction severity) was associated with reduced odds of severe reaction compared with giving multiple doses in a single day.

CONCLUSIONS

Distinct hematological changes may help support FPIES diagnosis. Current OFC assessment criteria may not capture the broad spectrum of acute FPIES presentations. This 2-day protocol may be associated with a reduced risk of severe reactions. Future work should aim to develop safer OFC and non-OFC diagnostics for FPIES.

Differences in Characteristics Between Patients Who Met or Partly Met the Diagnostic Criteria for Food Protein-Induced Enterocolitis Syndrome (FPIES)

BACKGROUND

Some patients with food protein-induced enterocolitis (FPIES)-like allergy do not completely fulfill the diagnostic criteria of the international consensus guideline for FPIES. However, it is unclear whether such FPIES-like patients represent a completely different population from FPIES.

OBJECTIVE

This study aimed to clarify differences in characteristics between patients with FPIES who fully met diagnostic criteria and those who partly met them.

METHODS

This was a cross-sectional study using data at the time of registration in multicenter, prospective studies of patients with FPIES in Japan. Children who had delayed emesis within 1 to 4 hours and/or diarrhea within 5 to 10 hours after ingestion of food were recruited between March 2020 and February 2022. We examined their compatibility with the diagnostic criteria of the international consensus guideline and their detailed clinical characteristics, including trigger foods, the serving size that elicited symptoms, and antigen-specific IgE antibody titers.

RESULTS

Of the 225 patients with FPIES, 140 fully met the diagnostic criteria whereas 79 patients did not fully meet them but demonstrated reproducible symptoms. The frequencies of pallor, lethargy, and diarrhea were significantly higher in those who met the criteria fully, whereas the age at onset, trigger foods, comorbidity, and perinatal information were comparable. Analysis of patients with FPIES to hen's egg revealed significantly higher levels of egg white- and egg yolk-specific IgE in patients who partly met criteria, whereas the serving size eliciting symptoms was comparable.

CONCLUSIONS

Patients who partly met the diagnostic criteria may have a milder phenotype of FPIES, but this needs to be validated in further studies using biomarkers reflecting the pathophysiology.

Heterogeneity of food protein-induced enterocolitis syndrome (FPIES)

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated food allergy with gastrointestinal symptoms such as vomiting and diarrhea. The development of international consensus guidelines for the diagnosis and management of FPIES in 2017 enabled us to compare patients worldwide, regardless of geographic variation in disease features. As a result, it has become clear that there is heterogeneity among patients with FPIES or that there are cases that partly fit the diagnostic criteria for FPIES but have different characteristics. This review highlights the heterogeneity in FPIES characteristics in terms of trigger foods, the age of onset, differences in geographic regions, and symptoms; it further proposes four disease entities, including acute FPIES in children, acute FPIES in adults, chronic FPIES, and early-onset neonatal FPIES, depending on the age of onset and presumed pathophysiology. The major symptoms at onset and trigger foods differ in acute FPIES in children, acute FPIES in adults, and chronic FPIES, whereas the disease entities may share a similar pathophysiology. Early-onset neonatal FPIES may have a different pathophysiology than acute or chronic FPIES, and may not necessarily fulfil the full diagnostic criteria for acute or chronic FPIES described in the international consensus guidelines. Due to the similarity in symptoms, early-onset neonatal FPIES may sometimes be misdiagnosed as necrotizing enterocolitis. We aim to increase awareness of FPIES among medical staff in pediatrics, neonatology, and internal medicine and promote research, to gain a better understanding of the heterogeneity and pathophysiology of FPIES.

Recent Update in Food Protein-Induced Enterocolitis Syndrome: Pathophysiology, Diagnosis, and Management

Food protein-induced enterocolitis syndrome (FPIES), though first reported in the 1970s, remains poorly understood and likely underdiagnosed. It is a non-immunoglobulin E (IgE)-mediated food allergy syndrome, most commonly identified in infancy and childhood. It can manifest as a constellation of symptoms following food ingestion, including repetitive and projectile emesis (1-4 hours), accompanied by pallor, lethargy, muscular hypotonia, and diarrhea (5-10 hours). In more severe reactions, significant leukocytosis with neutrophilia, thrombocytosis, metabolic derangements, methemoglobinemia, anemia, low albumin, and total protein may be present. Hypotension and ultimately hypovolemic distributive shock may occur in up to 15%-20% of cases. The diagnosis of FPIES is challenging and providers continue to face difficulties in management. This review article aims to highlight the most recent updates in epidemiology, natural history, pathophysiology, potential diagnostic markers, and guidelines for the management of FPIES.

The Natural Course of Adult-Onset Food Protein-Induced Enterocolitis Syndrome

BACKGROUND

Adult-onset food protein-induced enterocolitis syndrome (FPIES) has been increasingly recognized in recent years. Adult FPIES differs from pediatric FPIES in terms of dietary triggers and symptoms, thus further broadening the clinical phenotypes of the disease. The natural history of FPIES in adulthood is poorly characterized.

OBJECTIVE

To evaluate the natural course of FPIES in adults.

METHODS

We performed an ambispective study of adults diagnosed with acute FPIES during 2016-2021. Data on age, sex, symptoms, implicated food, and oral food challenge (OFC) outcomes at baseline and during follow-up were analyzed.

RESULTS

Forty-two adults were included (83.3% female; median age at diagnosis, 40 years). The predominant symptoms were diarrhea (92.9%) and abdominal cramps (71.4%); vomiting was reported by 59% of patients. The most common triggers were shellfish (n = 19, 45.2%) and fish (n = 19, 45.2%). The mean number of reactions before diagnosis was 6.3 (2-15). Twenty-one OFCs were carried out with the offending food in 15 patients. Six patients achieved tolerance (40%) after a mean of 17.8 months (range, 6-36 months). Twelve of all OFCs performed were positive (57.1%). The absolute leukocyte and neutrophil counts measured before and 1 to 2 hours after the positive challenge showed a mean increase of 3045 and 2736 cells/μL, respectively. Serum tryptase, C-reactive protein, and eosinophil and platelet values did not change significantly after the OFC.

CONCLUSION

Some patients may outgrow adult-onset FPIES.

Adult Food Protein-Induced Enterocolitis Syndrome

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE, cell-mediated food allergy, commonly diagnosed in infants and young children. In recent years, new-onset adult FPIES has been recognized. The underlying pathogenic mechanism of FPIES has yet to be elucidated, thus disease-specific diagnostic biomarkers have yet to be determined and an oral food challenge (OFC) remains the gold-standard for the diagnosis. Pediatric patients with FPIES classically present with symptoms of delayed, repetitive vomiting approximately 1 to 4 hours following ingestion of a food allergen. However, adults with FPIES have been reported to have a different symptom profile and different food triggers compared to the pediatric FPIES population. The current FPIES diagnostic criteria may not be appropriate for the diagnosis of adult FPIES patients, thus an oral food challenge remains a diagnostic tool. This review provides an overview of the current literature on the clinical presentation, epidemiology, diagnosis, triggers and management of adult FPIES.

Food Protein-Induced Enterocolitis Syndrome

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated food allergy that manifests with projectile, repetitive emesis that can be followed by diarrhea and may be accompanied by lethargy, hypotonia, hypothermia, hypotension, and metabolic derangements. FPIES usually starts in infancy although onset at older ages is being increasingly recognized. FPIES is not rare, with the cumulative incidence of FPIES in infants estimated to be 0.015% to 0.7%, whereas the population prevalence in the US infants was 0.51%. FPIES diagnosis is challenging and might be missed because of later (1-4 hours) onset of symptoms after food ingestion, lack of typical allergic skin and respiratory symptoms, and food triggers that are perceived to be hypoallergenic. Diagnosis is based on the recognition of symptoms because there are no biomarkers of FPIES. The pathophysiology remains obscure although activation of the innate immune compartment has been detected. Management relies of avoidance of food triggers, treatment of accidental exposures, and periodic re-evaluations with supervised oral food challenges to monitor for resolution. There are no strategies to accelerate development of tolerance in FPIES. Here we review the most important current concepts in epidemiology, pathophysiology, diagnosis, and management of FPIES.

A formula-fed infant with profound dehydration, cerebral venous sinus thrombosis, and intracranial hemorrhage

Background

Chronic food protein-induced enterocolitis syndrome (FPIES) is a cell-mediated gastrointestinal food hypersensitivity described almost exclusively in infants fed cow's milk or soy formula. A timely diagnosis is challenging due to a number of factors, including broad differential diagnoses, absence of specific biomarkers, and delayed symptom onset.

Objective

This report aimed to highlight how the severity of presentation can further impede a timely diagnosis in chronic FPIES. Methods: A case of presumed chronic FPIES to soy with previously unreported complications of intracranial hemorrhage and cerebral venous sinus thrombosis was described.

Results

We reported a case of a female infant fed a soy formula who presented during the third week of life with intermittent and progressive emesis, diarrhea, and lethargy, which culminated in severe dehydration, with early hospital course complications of seizures, intracranial hemorrhage, and cerebral venous sinus thrombosis. Although not recognized until weeks into the hospital course, many of the presenting symptoms and laboratory abnormalities were characteristic of chronic FPIES. An ultimate consideration of FPIES led to transition to amino acid-based formula and gradual resolution of gastrointestinal symptoms. Close outpatient follow-up was essential in facilitating subsequent age-appropriate solid food introduction.

Conclusion

The severity of presentation in FPIES can represent an additional barrier to a timely diagnosis. Early consideration of this entity in the differential diagnosis of patients with typical FPIES features, regardless of the additional presence of atypical and severe complications, may help with more timely recognition and intervention. In addition, there is an increased need for close follow-up as an outpatient in severe FPIES cases.

'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.

A 5-Month-Old Infant with Cardiorespiratory Arrest Caused by Food Protein-Induced Enterocolitis Syndrome to Cow's Milk Proteins

Food protein-induced enterocolitis syndrome (FPIES) is a nonimmunoglobulin E cell-mediated food allergy, which occurs predominantly in infants and young children. The most commonly incriminated triggers are cow's milk (CM), soy, and grains. Acute FPIES can be potentially life-threatening and culminate in shock requiring fluid resuscitation in at least 15% of the cases. To our knowledge, there have been no reports in literature of cardiorespiratory arrest induced by acute FPIES. We describe the first case of cardiorespiratory arrest occurred after accidental ingestion of a CM-based formula in a 5-month-old infant with previous diagnosis of FPIES to CM.

FPIES in exclusively breastfed infants: two case reports and review of the literature

Background

Food Protein-Induced Enterocolitis Syndrome (FPIES) is a non IgE-mediated food allergy that generally affects children in the first year of life. Usually symptoms break out when formula milk or solid foods are introduced for the first time but they might also appear in exclusively breastfed infants, since the trigger elements, especially cow’s milk proteins, can be conveyed by maternal milk as well. FPIES in exclusively breastfed babies is a very rare clinical condition and only few cases have been reported in the medical literature.

Case presentation

We describe two cases of FPIES in exclusively breastfed babies. The first one is a two-month-old infant with a brief history of vomit and diarrhea that presented to the Emergency Department in septic-like conditions. The main laboratory finding was a significant increase in methemoglobin (13%). Clinically, we noted that, when breastfeeding was suspended, diarrhea drastically improved, and vice versa when maternal milk was reintroduced. An amino acid-based formula allowed a complete normalization of the symptoms. The second one is a three-month-old infant admitted for a 3 days history of persistent vomit and diarrhea. Blood tests showed a raised level of methemoglobin (7%). An esophagogastroduodenoscopy was performed and biopsies showed an eosinophilic infiltration of the duodenal mucosa. A maternal exclusion diet and an amino acid-based formula allowed a rapid regularization of the bowel function.

Conclusions

We searched all the cases of FPIES in exclusively breastfed babies reported in the medical literature, identifying eight patients, with an average age of 3 months (range 15 days – 6 months). The majority of the cases were initially diagnosed as gastroenteritis or sepsis, five cases were characterized by an acute on chronic scenario and cow’s milk was the most frequently involved food. Methemoglobin was never tested. An oral food challenge test was performed in two patients.

FPIES in exclusively breastfed infants is a rare condition that, in the presence of compatible history and symptoms, should be considered also in exclusively breastfed babies. The evaluation of methemoglobin can simplify the diagnostic process.

New insights into food protein-induced enterocolitis in children

Food protein-induced enterocolitis syndrome (FPIES) represents a non-IgE-mediated food allergic disorder with delayed gastrointestinal symptoms that may evolve in a medical emergency. Clinically, FPIES can be distinguished into acute and chronic phenotypes. FPIES is mainly diagnosed in infancy however the onset at older ages is being progressively described. The pathogenetic mechanism underlying FPIES remains mainly unexplained, but an alteration of food-specific T-cell response has been proposed. The diagnosis of FPIES is primarily clinical, since there are not available specific biomarkers. Oral food challenge (OFC) is the gold standard for diagnosing FPIES or excluding the onset of tolerance to the triggering food. Management of FPIES includes an acute phase treatment and a maintenance therapy with the strict food avoidance until challenge, in order to prevent new attacks and avoid nutritional alterations. Acute management requires hydration that can be performed orally or intravenously according to clinical status. Long-term management of FPIES is based on the avoidance of the culprit food(s) and supervised introduction of other high-risk foods if never taken before among infants before 12 months of age. There is a compelling need of future achievements in FPIES research for the definition of underlying disease pathogenesis and potential therapeutic point of care.

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.

Japanese guidelines for food allergy 2020

Five years have passed since the Japanese Pediatric Guideline for Food Allergy (JPGFA) was first revised in 2011 from its original version. As many scientific papers related to food allergy have been published during the last 5 years, the second major revision of the JPGFA was carried out in 2016. In this guideline, food allergies are generally classified into four clinical types: (1) neonatal and infantile gastrointestinal allergy, (2) infantile atopic dermatitis associated with food allergy, (3) immediate-type of food allergy (urticaria, anaphylaxis, etc.), and (4) special forms of immediate-type of food allergy such as food-dependent exercise-induced anaphylaxis and oral allergy syndrome (OAS). Much of this guideline covers the immediate-type of food allergy that is seen during childhood to adolescence. Infantile atopic dermatitis associated with food allergy type is especially important as the onset of most food allergies occurs during infancy. We have discussed the neonatal and infantile gastrointestinal allergy and special forms of immediate type food allergy types separately. Diagnostic procedures are highlighted, such as probability curves and component-resolved diagnosis, including the recent advancement utilizing antigen-specific IgE. The oral food challenge using a stepwise approach is recommended to avoid complete elimination of causative foods. Although oral immunotherapy (OIT) has not been approved as a routine treatment by nationwide insurance, we included a chapter for OIT, focusing on efficacy and problems. Prevention of food allergy is currently the focus of interest, and many changes were made based on recent evidence. Finally, the contraindication between adrenaline and antipsychotic drugs in Japan was discussed among related medical societies, and we reached an agreement that the use of adrenaline can be allowed based on the physician's discretion. In conclusion, this guideline encourages physicians to follow the principle to let patients consume causative foods in any way and as early as possible.

Severity scales of non-IgE-mediated gastrointestinal food allergies in neonates and infants

BACKGROUND

Non-IgE-mediated gastrointestinal food allergies (non-IgE-GI-FAs) are one type of food allergy found in neonates and infants. Few reports have defined the severity of non-IgE-GI-FAs in these populations.

METHODS

Grading scales of the severity of non-IgE-GI-FAs according to extra-GI symptoms, such as poor weight gain, as well as systemic symptoms, including fever and shock, were developed and retrospectively applied to patients with non-IgE-GI-FAs. The relationship between the severity of non-IgE-GI-FAs and both clinical and laboratory findings were examined.

RESULTS

Elevation of C-reactive protein levels and a decrease in total protein and albumin were observed in accordance with allergy severity. In an endoscopic examination, inflammatory findings were confirmed in large areas of the colonic mucosa in case of higher severity levels, and infiltration of inflammatory cells other than eosinophils was found in the severest grade. Extensively hydrolyzed milk or amino acid-based milk was required for all patients with the severest grade. In addition, the timing of acquiring tolerance tended to be late for this grade.

CONCLUSIONS

Classification and determination of the severity of non-IgE-GI-FAs in neonates and infants may not only contribute to elucidation of the pathogenesis but may also be useful in the clinical setting.

Food protein-induced enterocolitis syndrome: a challenging diagnosis

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated gastrointestinal food hypersensitivity triggered by food proteins. It may present acutely, with repetitive vomiting, diarrhoea and lethargy leading to dehydration and eventually shock or insidiously with intermittent emesis, chronic diarrhoea or failure to thrive. We describe a paediatric male patient with recurrent sepsis-like episodes of fever, lethargy, ashen-grey skin colouration and vomiting followed by diarrhoea. These episodes were triggered by cow's milk formula and grains. Laboratory tests revealed leucocytosis, thrombocytosis, metabolic acidosis and elevated C reactive protein. After exclusion of other differential diagnoses, the diagnosis of FPIES was established on clinical improvement with withdrawal of the offending food and positive oral food challenge. FPIES diagnosis requires a high index of suspicion and is frequently delayed, which contributes to an increased morbidity. This is due to the wide spectrum of clinical presentations and due to the absence of specific diagnostic tests.

Food protein-induced enterocolitis syndrome: a review of the new guidelines

Food protein-induced enterocolitis syndrome (FPIES) is a non IgE-mediated gastrointestinal food allergy that presents with delayed vomiting after ingestion primarily in infants. While the pathophysiology of FPIES is poorly understood, the clinical presentation of acute FPEIS reactions has been well characterized. The first International Consensus Guidelines for the Diagnosis and Management of Food Protein–induced Enterocolitis Syndrome were published in 2017 and reviewed epidemiology, clinical presentation, and prognosis of acute and chronic FPIES. The workgroup outlined clinical phenotypes, proposed diagnostic criteria, and made recommendations on management. This article summarizes the guidelines and adds recent updates. FPIES is gaining recognition, however there continues to be delays in diagnosis and misdiagnosis due to overlap of symptoms with over conditions, lack of a diagnostic test, and because some of the common trigger foods are not thought of as allergenic. More research into disease mechanisms and factors influencing differences between populations is needed.

Increased serum cortisol on oral food challenge in infants with food protein-induced enterocolitis syndrome

BACKGROUND

An increase in absolute neutrophil count (ANC) is seen after oral food challenge test (OFC) in patients with food protein-induced enterocolitis syndrome (FPIES). Although it has been suggested that interleukin (IL)-8 is involved in this phenomenon, a possible role for cortisol has not yet been studied.

METHODS

Six positive OFC in five patients with FPIES due to cows' milk (CM) proteins, and two negative OFC in two patients with suspected FPIES were analyzed. Absolute neutrophil count, serum IL-8, and serum cortisol were measured before OFC, 6 and 24 h after the ingestion of CM formula.

RESULTS

For the positive OFC, ANC measured 6 h after the ingestion of CM formula was significantly higher than that measured before the OFC (median, 8,761 versus 2,297/μL; P < 0.05). Significant increases in serum cortisol and IL-8 were observed 6 h after OFC (cortisol, median 1,119 pg/mL before versus 2,141 pg/mL after, P < 0.05; IL-8, median 15.5 pg/mL before versus 165.3 pg/mL after, P < 0.05). The change ratio (i.e. ratio of that after OFC to that before OFC) of ANC was significantly correlated not only with that of serum IL-8 (r = 0.90, P < 0.01) but also with that of serum cortisol (r = 0.76, P < 0.05). Moreover, the serum cortisol change ratio was significantly higher in subjects with vomiting than in those without (median, 2.5 versus 1.0, P < 0.05).

CONCLUSIONS

Serum cortisol, in combination with IL-8, affects the increase in ANC after OFC.

Non-IgE-mediated gastrointestinal food allergies

PURPOSE OF REVIEW

We focus on recent advances regarding the epidemiology, physiopathology, diagnosis and managements of non-IgE-mediated gastrointestinal food allergies (non-IgE-GI-FAs), particularly food protein-induced enterocolitis syndrome (FPIES).

RECENT FINDINGS

The first international FPIES diagnostic and management guidelines have been recently published. Although FPIES largely remains a diagnosis of exclusion, it may be more prevalent than previously thought. Ondansetron has emerged as a major tool for the treatment of FPIES acute reactions. Recent data also suggest an important role for innate immune cells in FPIES pathogenesis.

SUMMARY

Despite major advances in the diagnosis and management of non-IgE-GI-FAs, particularly FPIES, the lack of specific diagnostic tests and biomarkers to guide clinical management remains challenging.

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.

A systematic review of food protein-induced enterocolitis syndrome from the last 40 years

OBJECTIVE

To provide a complete, exhaustive summary of current literature relevant to food protein-induced enterocolitis syndrome (FPIES).

DATA SOURCES

Data have been extracted from PubMed and Science Direct databases.

STUDY SELECTIONS

Following the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines, a literature search for peer-reviewed journal articles in English through January 1975 with updates through October 2016 was conducted. Relevant publications were reviewed that included pediatric and adult populations. Information on the study design, sample, intervention, comparators, outcome, timeframe, and risk of bias were abstracted for each article.

RESULTS

Of 135 reviewed reports, 52 were included in this systematic review. In accordance with the age at onset, clinical features, and offending foods, it is possible to distiguish different types of FPIES. An immune systemic involvement can occur in patients with FPIES. In addition to the most common causative foods (cow's milk, soy, and rice), any food can potentially cause FPIES. Although specific diagnostic tests are not available, open food challenge remains the gold standard for FPIES diagnosis. Moreover, because of the lack of randomized clinical trials and of use of different adopted methods, confounding factors might mask critical findings, leading to poor knowledge of this pleiotropic clinical entity.

CONCLUSION

Multicenter studies are needed to better develop an evidence-based approach to pathophysiology, prevalence, diagnosis, and natural history of the disease.

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.

Prognosis of infantile food protein-induced enterocolitis syndrome in Japan

BACKGROUND

Although serum C-reactive protein (CRP) and the percentage of eosinophils in peripheral blood (Eo) are increased at onset in infants with food protein-induced enterocolitis syndrome (FPIES), the relationship of these laboratory findings to prognosis is presently unknown.

METHODS

Correlation of serum CRP and Eo at onset with prognosis was analyzed in 32 patients with FPIES caused by cow's milk (CM).

RESULTS

The rate of tolerance acquisition was 18.8%, 56.3%, 87.5%, and 96.9% at the ages of 6, 12, 24, and 36 months, respectively. Serum CRP increased in 50% of subjects at onset (median, 0.21 mg/dL; range, <0.20-18.2 mg/dL) and Eo was elevated in 71.9% of subjects at onset (median, 7.1%; range, 1.0-50.5%). Age at tolerance acquisition was significantly positively correlated with serum CRP at onset (r = 0.45, P < 0.01), and significantly negatively correlated with Eo at onset (r = -0.36, P < 0.05). Although CM-specific immunoglobulin E antibody (sIgE) was positive in nine of 32 FPIES patients at onset (median, 0.93; range, 0.38-18.9 kU/L), it decreased thereafter. CM-sIgE at onset did not correlate significantly with prognosis (r = 0.22, P > 0.05).

CONCLUSIONS

Serum CRP is not only an indicator of the activity of intestinal inflammation, it is also a useful parameter of poor prognosis in FPIES. In contrast, eosinophilia at onset could be used as a marker of good prognosis, suggesting that it has some beneficial effects in the pathophysiology of FPIES.

Cytokine profile after oral food challenge in infants with food protein-induced enterocolitis syndrome

BACKGROUND

Although food protein-induced enterocolitis syndrome (FPIES) is supposed to be caused by inflammation, the role of cytokines has not yet been clarified.

METHODS

To elucidate the role of cytokines in the development of symptoms and abnormal laboratory findings at an oral food challenge (OFC), changes in serum cytokine levels were analyzed for 6 OFCs in 4 patients with FPIES. The result of OFC was judged positive if any gastrointestinal (GI) symptoms (vomiting, diarrhea, or bloody stool) were induced.

RESULTS

Among 11 cytokines profiled, serum levels of interleukin (IL)-2, IL-5, and IL-8 were clearly increased in all 4 positive OFCs in which elevations of the serum level of C-reactive protein (CRP) and peripheral blood neutrophilia were also seen. The level of serum IL-10 also rose in 2 positive OFCs. Remarkable increases in the serum level of interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), IL-6, and IL-12 were observed in a positive OFC where the serum level of CRP rose markedly (6.75 mg/dL). The serum levels of IL-5 were also elevated in 2 negative OFCs. No apparent specific correlations were found between cytokines and GI symptoms.

CONCLUSIONS

These results suggest that IL-2 and IL-8 are involved in the antigen-specific immune responses in most patients with FPIES. Further studies are needed to elucidate the significance of these cytokine in the pathogenesis of FPIES.

Japanese guidelines for food allergy 2017

Five years have passed since the Japanese Pediatric Guideline for Food Allergy (JPGFA) was first revised in 2011 from its original version. As many scientific papers related to food allergy have been published during the last 5 years, the second major revision of the JPGFA was carried out in 2016. In this guideline, food allergies are generally classified into four clinical types: (1) neonatal and infantile gastrointestinal allergy, (2) infantile atopic dermatitis associated with food allergy, (3) immediate-type of food allergy (urticaria, anaphylaxis, etc.), and (4) special forms of immediate-type of food allergy such as food-dependent exercise-induced anaphylaxis and oral allergy syndrome (OAS). Much of this guideline covers the immediate-type of food allergy that is seen during childhood to adolescence. Infantile atopic dermatitis associated with food allergy type is especially important as the onset of most food allergies occurs during infancy. We have discussed the neonatal and infantile gastrointestinal allergy and special forms of immediate type food allergy types separately. Diagnostic procedures are highlighted, such as probability curves and component-resolved diagnosis, including the recent advancement utilizing antigen-specific IgE. The oral food challenge using a stepwise approach is recommended to avoid complete elimination of causative foods. Although oral immunotherapy (OIT) has not been approved as a routine treatment by nationwide insurance, we included a chapter for OIT, focusing on efficacy and problems. Prevention of food allergy is currently the focus of interest, and many changes were made based on recent evidence. Finally, the contraindication between adrenaline and antipsychotic drugs in Japan was discussed among related medical societies, and we reached an agreement that the use of adrenaline can be allowed based on the physician's discretion. In conclusion, this guideline encourages physicians to follow the principle to let patients consume causative foods in any way and as early as possible.

Eosinophilia in infants with food protein-induced enterocolitis syndrome in Japan

BACKGROUND

Many Japanese infants with food protein-induced enterocolitis syndrome (FPIES) show eosinophilia, which has been thought to be a characteristic of food protein-induced proctocolitis (FPIP).

METHODS

To elucidate the characteristics of eosinophilia in Japanese FPIES patients, 113 infants with non-IgE-mediated gastrointestinal food allergy due to cow's milk were enrolled and classified into FPIES (n = 94) and FPIP (n = 19).

RESULTS

The percentage of peripheral blood eosinophils (Eo) was increased in most FPIES patients (median, 7.5%), which was comparable with that in FPIP patients (9.0%). Among FPIES patients, Eo was the highest in patients who had vomiting, bloody stool, and diarrhea simultaneously (12.9%) and lowest in patients with diarrhea alone (3.2%). Eo showed a significant positive correlation with the incidence of vomiting (Cramer's V = 0.31, p < 0.005) and bloody stool (Cramer's V = 0.34, p < 0.0005). A significant difference was found in Eo between early- (≤10 days, n = 56) and late-onset (>10 days, n = 38) FPIES (median, 9.8% vs. 5.4%; p < 0.005). IL-5 production by peripheral blood T cells stimulated with cow's milk protein in early-onset FPIES was significantly higher than that in late-onset FPIES (67.7 pg/mL vs. 12.5 pg/mL, p < 0.01), and showed a significant positive correlation with Eo (rs = 0.60, p < 0.01).

CONCLUSIONS

This study demonstrated two types of eosinophilia in Japanese FPIES infants: conspicuous and mild eosinophilia in early- and late-onset FPIES patients, respectively. Conspicuous eosinophilia in early-onset FPIES is suggested to be caused by abnormally high IL-5 production.

Serum C-reactive protein in food protein-induced enterocolitis syndrome versus food protein-induced proctocolitis in Japan

BACKGROUND

Some infants with food protein-induced enterocolitis syndrome (FPIES) have increased serum C-reactive protein (CRP) and fever in Japan. The aim of this study was therefore to clarify and compare the incidence of this in patients with FPIES versus patients with food protein-induced proctocolitis (FPIP).

METHODS

One hundred and sixteen infants with non-IgE-mediated gastrointestinal food allergies were enrolled in this study and classified into three phenotypes: FPIES presenting with vomiting and/or diarrhea (n = 47); FPIP with bloody stool alone (n =19); and the mixed phenotype (MP), bloody stool with vomiting and/or diarrhea (n = 50).

RESULTS

Serum CRP was increased in 55.3% of the FPIES group, similar to that in the MP group (54.0%), and significantly higher than in the FPIP group (15.8%; P < 0.01). Fever was observed in 29.8% of the FPIES group, significantly higher than in the MP group (8.0%; P < 0.01) and in the FPIP group (0%; P < 0.05). Patients with fever had significantly higher serum CRP than patients without fever (median, 12.8 vs <0.2 mg/dL, P < 0.00001).

CONCLUSIONS

Serum CRP was significantly higher in the FPIES group than in the FPIP group. This suggests that serum CRP is a useful marker for differentiating the pathogenesis of FPIES from FPIP. From the perspective of serum CRP, the pathology of the intestinal inflammation in MP subjects is suggested to be similar to that of FPIES.