Relationship between the diagnosis of food protein–induced enterocolitis syndrome and postemetic procalcitonin levels

Background: There are no reports on the relationship between food protein–induced enterocolitis syndrome (FPIES) diagnosis and procalcitonin levels. Objective: Our study sought to demonstrate a correlation between the presence or absence and severity of FPIES symptoms and postemetic procalcitonin levels. Methods: The subjects were 53 patients with FPIES (44 with hen’s egg allergy, 4 with milk allergy, 4 with wheat allergy, and 3 with soy allergy), who collectively underwent a total of 75 oral food challenges (OFCs). Procalcitonin levels at 5 hours after antigen ingestion were compared between patients with a positive OFC result and those with a negative OFC result and between patients who experienced mild or moderate events and those who experienced severe events. Results: At 5 hours after ingestion of the causative food, the median procalcitonin levels in patients with a negative OFC result, patients who experienced a mild or moderate event, and patients who experienced a severe event were 0.02, 0.03, and 0.16 ng/mL, respectively. The procalcitonin level was significantly higher in the groups with a positive OFC result than in the groups with a negative OFC result (P < .001), and it was significantly higher in those who experienced severe events than in those who experienced mild or moderate events (P = .012). Conclusion: Measurement of procalcitonin levels has the potential to provide a quantitative and objective assessment of FPIES diagnosis and severity.