Implementing The Food Ladder For Tolerance Acquisition In A Pediatric Case With Food Protein-Induced Enterocolitis Syndrome

Abstract

Background: Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated food allergy predominantly diagnosed in infancy and early childhood. The acute form is characterized by symptoms such as repetitive vomiting, pallor, diarrhea, and, in severe cases, hypovolemic shock following ingestion of the allergen food. To date, the only traditional treatment is strictly eliminating allergens in food. However, unlike prolonged elimination strategies, applying a food ladder (milk ladder) approach, commonly used in IgE-mediated food allergies, may facilitate earlier tolerance acquisition in selected FPIES cases.

Case presentation: A 5-month-old female infant presented with projectile vomiting, coughing, fatigue, and subsequent diarrhea approximately 2 hours after consuming yoghurt. The presence of projectile vomiting, lethargy, and diarrhea prompted a preliminary diagnosis of non-IgE-mediated FPIES. In contrast, the combination of vomiting and coughing raised clinical suspicion of IgE-mediated anaphylaxis, which is defined as IgE-mediated. Following comprehensive clinical and laboratory evaluation, a diagnostic oral food challenge (OFC) confirmed a diagnosis of acute, early-onset, severe, and atypical FPIES triggered by milk protein. After maintaining a strict milk protein elimination diet for over 1 year, two separate OFCs with unprocessed milk were conducted to assess the development of tolerance, both of which yielded adverse outcomes that were related to FPIES. Subsequently, a stepwise reintroduction protocol based on the food ladder (milk ladder), consisting of milk products processed at varying degrees, including extensively baked, fermented, and eventually unprocessed forms, was implemented, resulting in the successful acquisition of tolerance (cake, yoghurt, milk, respectively).

Conclusion: In IgE-mediated food allergies, the food ladder (milk ladder) is a well-established approach to induce tolerance. Although FPIES represents a non-IgE-mediated hypersensitivity, current evidence supporting such stepwise reintroduction strategies in this context remains limited. Prolonged and unnecessary elimination of allergen foods can have significant repercussions on the child's nutritional status and the family's psychosocial well-being, ultimately impairing quality of life. Our case highlights the potential utility of the food ladder (milk ladder) as an effective strategy for achieving tolerance in patients with non-IgE-mediated FPIES, offering an alternative to unnecessarily prolonged food restrictions.

Keywords: Food protein-induced enterocolitis syndrome; food ladder; milk ladder; oral food challenge; tolerance.