Reducing public health costs with infant formulas: oral food challenge and misdiagnosed or outgrown cow’s milk protein allergy

Background: Accurate diagnosis and appropriate management of cow’s milk protein allergy (CMPA) are crucial for avoiding unnecessary prescription of infant formulas. Here, we aimed to use the oral food challenge (OFC) for CMPA confirmation and for assessing development of natural tolerance to milk, in children with clinical CMPA diagnosis. We also assessed the economic impact in public health-care costs of reducing the prescription of infant formulas (provided by the São Paulo State’s public health service, in Brazil, until two years of age) after ruling out CMPA diagnosis in children with negative OFC results. Methods: We reviewed medical records of 76 children [41 males, median age = 2.0 years (0.8-5.0)] who underwent OFC from January 2016 to June 2018, 30 of whom were ≤2 years old. Results: Before OFC, 52 (68.4%), 20 (26.3%) and five (5.3%) children were diagnosed with non-IgE-mediated, IgE-mediated and mixed CMPA, respectively. Most children were fed with aminoacid-based formulas (n=29, 38%). OFC was negative in 58 (76%) children, thus ruling out CMPA diagnosis. Out of 18 (24%) OFC-positive children, most (n=10, 56%) had gastrointestinal symptoms. After ruling out CMPA diagnosis, a mean of 152.3 formula cans (2,161.14 US dollars) were saved per children by the public health service. The total amount saved was 64,834.27 US dollars. Conclusions: OFC proved important not only for ruling out misdiagnosed CMPA, but also for preventing the indiscriminate use of infant formulas, which, in turn, had positive consequences for public health costs.