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

Neonatal Food Protein-Induced Enterocolitis: Current Insights and Knowledge Gaps

Acute and chronic Food Protein-Induced Enterocolitis Syndrome (FPIES) has been well characterized in children; otherwise, neonatal FPIES (N-FPIES) remains poorly understood. In terms of pathophysiology, neonatal FPIES appears to have a more prevalent TH2 response and is characterized by specific clinical features that make the diagnosis challenging. Genetic and environmental risk factors may predispose to the development of FPIES. Recent evidence indicates that a characteristic microbiota signature may lead to barrier dysfunction, reduced regulatory T cells, and abnormal intestinal production of serotonin, responsible for the symptoms of FPIES. Regarding clinical presentation, newborns with FPIES may not fully meet the current guideline's diagnostic criteria at disease onset, being more similar to clinical entity specific of neonatal age than to acute FPIES in infants and children. Hence, differentiation from other neonatal medical and surgical conditions-particularly necrotizing enterocolitis (NEC)-remains a critical challenge for clinicians. This present review highlights our current understanding of N-FPIES, in term of pathophysiology, clinical presentation diagnosis, and treatment strategies. Refining diagnostic criteria for N-FPIES represents a clinical priority to help physicians in diagnosing and managing this challenging condition. Last, but not least, larger clinical trials are needed to optimize treatment practices in term and preterm newborns with FPIES.

A nationwide survey of non-IgE-mediated gastrointestinal food allergies in neonates and infants

BACKGROUND

Non-IgE-mediated gastrointestinal food allergies (non-IgE-GIFAs) seem to be increasing rapidly worldwide. However, nationwide studies have been limited to food-protein-induced enterocolitis (FPIES) and food-protein-induced allergic proctocolitis (FPIAP), with little attention to other non-IgE-GIFA subgroups. The aim of this study was to elucidate the clinical features of all patients with non-IgE-GIFAs, not just certain subgroups.

METHODS

We conducted a nationwide cross-sectional survey of non-IgE-GIFAs in Japan from April 2015 through March 2016. A questionnaire was sent to hospitals and clinics throughout Japan. The questionnaire asked about the number of physician-diagnosed non-IgE-GIFA patients, the status of fulfillment of the diagnostic criteria, tentative classification into 4 clusters based on the initial symptoms, the day of onset after birth, complications, and the suspected offending food(s).

RESULTS

The response rate to that questionnaire was 67.6% from hospitals and 47.4% from clinics. Analyses were conducted about "diagnosis-probable" patient cohort (n = 402) and the "diagnosis-confirmed" patients (n = 80). In half of the reported non-IgE-GIFA patients, onset occurred in the neonatal period. The patients were evenly distributed among 4 non-IgE-GIFA clusters. In Cluster 1, with symptoms of vomiting and bloody stool, the onset showed a median of 7 days after birth, which was the earliest among the clusters. Cow's milk was the most common causative food.

CONCLUSIONS

In half of the patients, the onset of non-IgE-GIFAs was in the neonatal period. This highlights the importance of studying the pathogenesis in the fetal and neonatal periods.

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.

Impact of Delayed Time to Antibiotics in Medical and Surgical Necrotizing Enterocolitis

This study investigated whether delayed receipt of antibiotics in infants with necrotizing enterocolitis (NEC) is associated with disease severity. In this retrospective, single-center cohort study of infants diagnosed with NEC over 4 years, we compared the timing of antibiotic administration in infants (time order placed to time of receipt) in medical and surgical NEC. Cases were independently reviewed, then various clinical factors were compared. Of 46 suspected cases, 25 were confirmed by a panel of radiologists with good interrater reliability (ICC 0.657; p < 0.001). Delays in antibiotic receipt were 1.7× greater in surgical than medical NEC cases (p = 0.049). Every hour after order entry increased the adjusted odds of surgical NEC by 2.4 (1.08−5.23; p = 0.032). Delayed antibiotic receipt was more common in infants with surgical than medical NEC. Larger studies will be needed to investigate if optimizing antibiotic expediency could improve intestinal outcomes.

Necrotizing enterocolitis associated with food protein-induced enterocolitis syndrome: A case report

INTRODUCTION

Food protein-induced enterocolitis syndrome (FPIES) is a T-cell-mediated allergy that can occur in newborns and infants who are introduced to milk protein. Some of the serious complications of FPIES include necrotizing enterocolitis (NEC), massive bloody stools, and disseminated intravascular coagulation. Here we report a case of NEC caused by FPIES.

PRESENTATION OF CASE

A 28-day-old girl born at full term suddenly developed marked abdominal distention and shock a few hours after being fed highly regulated milk protein. Emergency laparotomy was performed, and extensive small-intestinal necrosis was found. The histological examination showed chronic inflammation with typical ghost crypts, hemorrhage, and extensive pneumatosis intestinalis, a presentation consistent with NEC.

DISCUSSION

In this case, the fragile intestinal mucosa associated with FPIES was stimulated by milk protein, leading to NEC. The greatest diagnostic difficulty is the lack of a definitive method for distinguishing between NEC and FPIES. The allergen-specific lymphocyte stimulation test with lactotransferrin was positive, indicating that the primary condition was FPIES. However, no eosinophilic infiltrate was found in the histological examination, but there was chronic inflammation with typical ghost crypts, hemorrhage, and extensive pneumatosis intestinalis. Consequently, the final histological diagnosis in our case was NEC rather than FPIES.

CONCLUSION

FPIES has a variable clinical course, and severe FPIES may become exacerbated even after ingestion of highly regulated milk protein. Taking appropriate actions after correct diagnosis can prevent progression to surgical emergency and secondary NEC.

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 challenging diagnosis of food protein-induced enterocolitis syndrome: A case report series

Food protein-induced enterocolitis syndrome (FPIES) is a type of non-immunoglobulin E (IgE)-mediated food allergy. However, in addition to vomiting and diarrhea, IgE-mediated skin or respiratory symptoms may be comorbidities in some patients with FPIES. We described four unusual cases of neonates with FPIES, whose clinical presentations were variable and misleading. All patients experienced vomiting, diarrhea or other gastrointestinal symptoms, and three of them developed IgE-mediated food allergy. Case 1 was admitted to the hospital with convulsions and then developed severe sepsis and necrotizing enterocolitis (NEC)-like appearance. Case 2 was wrongly diagnosed with Stevens-Johnson syndrome due to a severe extravasation rash of the skin and mucous membranes and a systemic inflammatory response. There was unexplained cholestasis in case 3, which might be attributed to food allergy. Asymptomatic elevation of C-reactive protein was the only hint at early-stage FPIES in case 4. Moreover, there were increased serum food-specific IgG values in three of the above cases. After eliminating the offending food, all of the above clinical manifestations rapidly improved in the four cases; thus, we believe that the most correct diagnosis in the described four cases was FPIES. This case report series should further draw clinicians' attention to FPIES with variable and atypical symptoms. The usefulness of IgG levels in identifying the presence of FPIES is uncertain.