Acute food protein-induced enterocolitis syndrome in Switzerland: a 10-year retrospective review.

Food protein-induced enterocolitis syndrome (FPIES) is a non-immunoglobulin E-mediated food allergy that typically causes delayed gastrointestinal symptoms following the ingestion of a trigger food. FPIES is a rare condition with limited epidemiological data. This study aimed to investigate the demographic characteristics, triggers, clinical presentations, and outcomes of children with acute FPIES at the University Children's Hospital Zurich, a tertiary-level children's hospital in Switzerland, with a dual focus on confirmed and suspected FPIES cases. This retrospective study covered a 10-year period (2010-2020). Electronic medical records were screened for patients diagnosed with acute FPIES and those with symptoms suggestive of FPIES according to international diagnostic criteria. Those paediatric patients with an acute FPIES diagnosis or a history highly suggestive of FPIES were included. A total of 109 patients with acute FPIES were identified. Cow's milk (CM) was the most common food trigger (24%), followed by eggs (12%) and fish (10%). A single food trigger was identified in 56% of the patients. The median age of onset was 6 months (interquartile range (IQR), 4 months). Gender had no effect on observed FPIES cases. Data on FPIES tolerance and therefore resolution of FPIES symptoms and/or successful reintroduction of the triggering food were limited, with sufficient follow-up information available for only 37% of confirmed and 25% in suggestive cases: 27.5 months for CM (IQR, 15.75 months), 67.5 months for fish (IQR, 33.5 months), and 32 months for egg (IQR, 14.5 months).  Conclusion: The study contributes practical epidemiological and clinical insights into FPIES triggers, patterns, and patient characteristics, and provides further regional insights to navigate this complex condition. What is Known:  • FPIES is a rare, non-IgE-mediated food allergy, particularly affecting infants and young children. • FPIES is often under-recognized, resulting in delayed diagnosis and management. What is New: • By providing robust real-world data on acute FPIES, this study provides a decade-long overview of acute FPIES cases, detailing key food triggers, identifying gaps in clinical practice and delays in diagnosis, and contributing regional epidemiologic data that may not be apparent in short-term studies and underscore geographic variability in presentation and triggers.