What is the natural history of FPIES in adulthood?
Published: June 23, 2022
Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE mediated food allergy that manifests as delayed, reproducible, gastrointestinal symptoms that can progress to dehydration and shock. Although FPIES is classically described in the pediatric population, it is increasingly recognized in adults in recent years. Adult-onset FPIES appears to be relatively uncommon, differs from pediatric FPIES regarding dietary triggers and range of symptoms, and as such may be underdiagnosed. Small case series suggest that FPIES in adulthood might be persistent, but it is unknown whether remission could occur naturally, and prospective studies examining pathophysiology and natural history are lacking.
In a research article recently published in The Journal of Allergy and Clinical Immunology: In Practice, Crespo et al. explore the natural history of adult-onset FPIES in a Spanish cohort. They included 42 adult patients that developed FPIES during adulthood. All of them previously tolerated the offending trigger and were offered an oral food challenge (OFC), after a period of food avoidance, to assess tolerance. The main clinical characteristics and remission patterns of these adult patients were analyzed in this study.
The most common triggers were shellfish and fish, both reported as triggers in 45.2% of cases. Multiple food FPIES was reported by 6 patients (14.2%), with fish and shellfish being the main association (5 patients). The prevailing symptom reported was diarrhea (92.9%). Repetitive vomiting, defined as the major criterion outlined in international consensus guidelines in children, was absent in more than a third of adult-onset FPIES cases. The low index of suspicion in adults was also reflected in the recurrence of the episodes: 21.4% of patients reported more than 10 reactions to confirm linkage to specific foods. Twenty-one OFCs with the offending food were carried out in 15 patients. Six patients achieved tolerance (40%) and could reintroduce the culprit food in their diet. Twelve OFCs were positive and elicited mild-to-moderate symptoms, with no cases of hypotension or dehydration. The absolute leukocyte and neutrophil counts measured before and 1 to 2 hours after the positive OFC showed a mean increase of 3045 and 2736 cells/mL, respectively, but only 3 patients had a neutrophil count >1500 cells/mL, which constitutes a minor criterion for the interpretation of an OFC as positive. Serum tryptase, C-reactive protein, and eosinophil and platelet values did not change significantly after the OFC, and therefore do not seem useful to support the diagnosis.
This study highlights that symptoms of adult-onset FPIES differ from the pediatric presentation and that achieving food tolerance is possible in some patients.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.