Increased IgE-Mediated Food Allergy With Food Protein-Induced Allergic Proctocolitis

Abstract

To examine the relationship between food protein-induced allergic proctocolitis (FPIAP) and the risk of developing immunoglobulin E–mediated food allergy (IgE-FA) in infants.In the study, the researchers included 903 infants who were enrolled in the Gastrointestinal Microbiome and Allergic Proctocolitis (GMAP) cohort, an observational healthy-infant cohort study in which researchers characterized the epidemiology of FPIAP in the primary care setting.Infants diagnosed with FPIAP with presence of documented blood in the stool were included. IgE-FA was determined by 2 allergists independently reviewing clinical and sensitization data from children whose parents reported suspect reactions and included if both reviewers agreed the diagnosis was “confirmed” or probable.” The rate of IgE-FA was compared between healthy infants and those with FPIAP. Additional variables, including the presence of eczema, were evaluated by using univariable and multivariable logistic regression.More children with FPIAP developed IgE-FA (11%), compared with healthy children (5%). Adjusting for eczema, children with FPIAP had twice the odds of developing IgE-FA to any food. FPIAP was most strongly associated with IgE-FA to milk, although the study was not powered to detect relationships to individual foods.Children with FPIAP were at an increased risk for having IgE-FA. This may be multifactorial, including shared pathogenesis in the development of FPIAP and IgE-FA and/or an effect of antigen elimination diet used to treat FPIAP.FPIAP is a common diagnosis early in infancy that is benign and self-resolved. However, a diagnosis of FPIAP often leads to prolonged dietary restriction from cow’s milk (the most common cause) and potentially soy protein as well. Although conventional teaching is to wait until 12 months of age to reintroduce dairy to infants with FPIAP, it can likely be introduced much earlier. In this study, researchers found an association between a diagnosis of FPIAP with increased risk for IgE-FA, although diagnosis was not confirmed through oral food challenges. Although the authors report some potential common immunologic pathways between FPIAP (a non–immunoglobulin E–mediated food reaction) and IgE-FA, a true causative effect has not been established. Now that current evidence-based guidelines recommend early introduction of allergenic foods to all infants (beginning ∼4-6 months of age) and ongoing inclusion in the diet as the best path toward food allergy prevention, with this study, the authors reinforce the need for pediatricians to discuss these guidelines with parents. This is especially true in infants at a higher risk to develop food allergy, including those with severe or persistent atopic dermatitis and now, potentially, other forms of non–immunoglobulin–mediated food allergy. Now, more than ever, we need to let the infants eat!