Severity trend of recurrence in pediatric Food Protein-Induced Enterocolitis Syndrome (FPIES).

Background: Reintroduction of offending food in pediatric patients affected by Food Protein-Induced Enterocolitis Syndrome (FPIES) is carried out in hospitals with Oral Food Challenge (OFC), which leads to long waiting time and increases the societal burden of medical cost and human resources.

Objective: The aim of the study is to assess severity trend of acute FPIES adverse reactions over time in the same patient for possible outpatient or home reintroduction of offending food.

Methods: All children (<18 years-old) with a diagnosis of acute FPIES referred to 2 Italian pediatric allergy clinics were retrospectively enrolled. To determine if home or outpatient clinic reintroduction of trigger food was possible, a risk of severe reactions <5% was arbitrarily considered acceptable.

Results: Of the 202 patients enrolled, 23 (11,4%) presented increasing severity from mild-moderate to severe episode. None of the variables analyzed in these patients (sex, age at onset and interval between first and severe episode) had a statistically significant influence on the risk of more severe reactions. Of all patients initially presented mild or moderate episodes, 15.2% and 13.9% later manifested severe episodes over time, respectively. Of patients with cow's milk FPIES started with a mild episode, 5.5% later experienced a severe episode.

Conclusions: Performing OFC for acute FPIES is not safe enough at home, because the probability of severe adverse reaction is >5%. However, it could be considered to perform OFC in outpatient clinic in patients with cow's milk FPIES started with a mild episode and if a rapid transfer plan to emergency department is available.