The prevalence and natural course of food protein-induced enterocolitis syndrome to cow's milk: a large-scale, prospective population-based study

Background: The prevalence and natural history for food protein-induced enterocolitis syndrome (FPIES) have not been determined.

Objective: We sought to determine the prevalence, clinical manifestations, and rate of recovery for FPIES in a large-scale, population-based prospective study.

Methods: In a prospective study the feeding history of 13,019 infants was obtained. Infants with probable adverse reactions to cow's milk protein (CMP) were clinically examined, skin prick tested, and challenged orally. Diagnostic criteria for CMP-induced FPIES included age less than 9 months, delayed recurrent vomiting (usually with nausea), and lethargy after exposure to CMP in the absence of other IgE-mediated symptoms, such as rash, urticaria, and respiratory symptoms. In addition, a positive challenge response to milk resulted in the above-mentioned gastrointestinal symptoms, removal of milk from the diet resulted in the resolution of those symptoms, or both.

Results: Ninety-eight percent of the cohort participated in the study. The cumulative incidence for FPIES was 0.34% (44/13,019 patients). The most common symptoms were recurrent vomiting (100%), lethargy (77%) diarrhea (25%), pallor (14%), and bloody diarrhea (4.5%). All patients had FPIES within the first 6 months of life. By the age of 3 years, 90% of the patients had recovered. We did not detect any concomitant reaction to soy. Eight patients with FPIES had IgE-mediated cow's milk allergy (IgE-CMA).

Conclusions: The prevalence of FPIES is significant, and its clinical presentation is distinct from that of IgE-CMA. Most patients with FPIES recover, although a proportion might convert to IgE-CMA. The likelihood for a cross-reactivity to soy in this population was less than previously estimated.