Is food protein induced enterocolitis syndrome only a non IgE-mediated food allergy?

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.

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.

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.

Food Protein-Induced Enterocolitis Syndrome: Proposals for New Definitions

Acute food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated allergy and is characterized by repetitive profuse vomiting episodes, often in association with pallor, lethargy, and diarrhea, presenting within 1-4 h from the ingestion of a triggering food. In 2017, the international consensus guidelines for the diagnosis and management of FPIES were published. They cover all aspects of this syndrome, which in recent decades has attracted the attention of pediatric allergists. In particular, the consensus proposed innovative diagnostic criteria. However, the diagnosis of acute FPIES is still currently discussed because the interest in this disease is relatively recent and, above all, there are no validated panels of diagnostic criteria. We propose some ideas for reflection on the diagnostic and suspicion criteria of acute FPIES with exemplary stories of children certainly or probably suffering from acute FPIES. For example, we believe that new definitions should be produced for mild forms of FPIES, multiple forms, and those with IgE-mediated symptoms. Moreover, we propose two clinical criteria to suspect acute FPIES and to refer the child to the diagnostic oral food challenge.