Cow's milk protein-induced FPIES: Clinical outcomes in severe cases

Problem considered Food Protein-Induced Enterocolitis Syndrome (FPIES) is a rare and poorly understood condition that primarily affects infants and young children. This study aimed to evaluate the clinical characteristics and outcomes of patients diagnosed with severe cow's milk protein-induced FPIES. Methods A case series was conducted involving pediatric patients who underwent oral food challenges OFCs for FPIES exclusively triggered by cow's milk protein, followed at the pediatric gastroenterology outpatient clinic of a quaternary hospital between January 16, 2018, and June 20, 2024. Results A total of six patients were included, and 24 OFCs were assessed. The median age at symptom onset was 44 days (range: 3–99 days). Before the first OFC, the median duration of the elimination diet was 11.2 months (Q1: 8.7 – Q3: 27 months; IQR: 18.3 months); for patients requiring additional OFCs, the median duration was 35.17 months (Q1: 27.27 – Q3: 72.2 months, IQR: 44.93). All patients required admission to the intensive care unit. Two patients were formula-fed, three received mixed feeding, and one received whole cow's milk. Three patients had a family history of atopy, and one had a personal history of atopy. One patient had Down syndrome (DS), one was otherwise healthy, one had a genetic disorder (3p deletion/16q duplication), and three patients had cytomegalovirus infection. All patients developed tolerance to cow's milk protein, with a median time of 33 months (range: 17–103 months). Conclusions While the overall prognosis of FPIES was favorable, managing cases with severe initial symptoms necessitating ICU admission is complex and frequently involves multiple OFC before achieving tolerance.