Food Protein-Induced Allergic Proctocolitis May Have Distinct Phenotypes

Abstract

To investigate the prevalence of immunoglobulin E (IgE) sensitization and transition to IgE-mediated allergy to the culprit food or other concomitant foods in infants with food protein-induced allergic proctocolitis (FPIAP).In this retrospective study, we included 204 infants with confirmed FPIAP, evaluated between January 2015 and December 2018 at Hacettepe University, in Ankara, Turkey.Infants were categorized into 3 groups on the basis of clinical history, serum immunoglobulin E (sIgE) levels, and skin-prick tests (SPTs). Group 1 was those with FPIAP with or without IgE-mediated food hypersensitivity to offending and “nonoffending” foods at the initial consultation (n = 180). Group 2 was those with FPIAP with IgE sensitization but no clinical hypersensitivity symptoms to offending foods at onset or during study follow-up (n = 17), and group 3 was those with FPIAP with no sensitization at onset but who had a later transition to IgE-mediated hypersensitivity at follow-up (n = 7).FPIAP onset occurred at a median age of 2 months (25% to 75%; interquartile range [IQR]: 1.0–3.0). Milk was the trigger for 62.7% (n = 128). In 36.7% (n = 75), the trigger was milk plus other foods, and 0.5% (n = 1) had a trigger that was not milk. Children developed tolerance at a median of 12 months (IQR: 10.0–14.0). Among 180 infants in group 1, 86% (n = 156) did not show IgE to any food, 7.7% (n = 14) had IgE sensitization to offending foods at the initial consultation, and 9 of these 14 patients had symptoms of both IgE-mediated allergy and FPIAP to cow’s milk (CM) and egg white at onset of FPIAP. The median age of tolerance in group 1 was 11 months (IQR: 10–14]. Group 2 had sensitization to FPIAP triggering foods but no symptoms of IgE-mediated allergy. Twelve had positive SPT or sIgE to CM, 3 were positive to egg, and 3 had positive test results to CM and egg (the median sIgE to CM was 0.5 kUA/L; the median IgE to egg was 2.1 kUA/L at FPIAP onset). The median age of tolerance to FPIAP trigger foods in group 2 was 11 months (IQR: 9.5–12). Group 3 developed IgE-mediated symptoms to trigger foods at a median age of 5 months (IQR: 5–6). The median age of tolerance to IgE-mediated FPIAP triggering foods was 19 months (IQR: 18.0–29.0). Children with multiple food FPIAP developed tolerance later than those with single-food FPIAP (the median age for multiple food FPIAP groups was 13 months [IQR: 11–16] versus that of single-food FPIAP, which was 11 months [IQR: 10–13]; P < .001).On the basis of this study, some infants with FPIAP may transition to different food allergy clinical phenotypes, including IgE-mediated hypersensitivity to FPIAP triggering foods. Although all infants in the study developed tolerance, there was a delay in tolerance development among infants who transitioned to IgE-mediated hypersensitivity, compared with that of other groups. Those with multiple food FPIAP also had delayed tolerance when compared with infants with single-food FPIAP.Because of the retrospective nature, the strength of the conclusions are limited by a lack of systematic timing of challenge to trigger foods in infants with FPIAP and IgE-mediated allergy. Nonetheless, this information can be useful in counseling families regarding the likely time to resolution when concomitant IgE-mediated symptoms occur in individuals initially diagnosed with FPIAP and those with multiple food FPIAP. Unfortunately, they were not able to determine risk factors for development of IgE-mediated allergy in these infants with FPIAP. Further prospective studies are needed.