Adults with FPIES may face delayed diagnoses

Background Food protein-induced enterocolitis (FPIES) is a non-IgE-mediated food allergy that is becoming increasingly recognized in adults. The time between age at symptom onset (ASO) and age at diagnosis (AD) along with factors impacting this gap have not been fully studied. Objective We sought to investigate the latency between ASO and AD in adults with FPIES. We also sought to evaluate whether those with symptom onset in earlier years and those with comorbid gastrointestinal disease had greater mean latency. Methods We conducted a retrospective chart review for FPIES patients seen in the University of Michigan Allergy and Immunology clinic from 2015 to 2022. Patients 18 years and older diagnosed with FPIES by an allergist were included (N=19). Data including characteristics of patients’ prior FPIES reactions and past medical history were collected. Results The median FPIES ASO was 26 years and median AD was 35 years. The median difference between ASO and AD was 10 years and statistically significant via paired t-test (p=0.003). There was a negative correlation of -0.99 between year of symptom onset and latency between ASO and AD (p<0.0001). Those with previously diagnosed GI conditions had higher mean latency between ASO and AD than those without (p=0.124). Conclusions We noted a gap between ASO and AD in adults with FPIES. This may be due to under recognition of adult FPIES in the past given the negative correlation with mean latency between ASO and AD. Furthermore, co-morbid GI illnesses may be masking FPIES symptoms in adults and delaying diagnosis.