Objective: Food protein-induced allergic proctocolitis (FPIAP) is a non–immunoglobulin E (IgE) mediated food allergy that typically presents with blood-mixed mucoid stool. This study aimed to determine the clinical features of children with FPIAP and the factors affecting the development of tolerance.

Material and Method: Patients developed tolerance among those with a diagnosis of FPIAP who were admitted to Hatay Education and Research Hospital Pediatric Allergy-Immunology outpatient clinic between 01.07.2021 and 01.11.2022 were included in the study. The clinical and demographic characteristics of the patients, laboratory findings, age of tolerance and family history of atopy were recorded.

Results: Ninety one patients, 60.4% of whom were male with a median (IQR) age of 4.7 months (3.5-5.8 months) were included in the study. The median age of symptom onset was 2 months (1.3-3 months). Seven patients (7.7%) had concomitant IgE-mediated food allergy and 23 (25.3%) patients had atopic dermatitis. Family history of atopy was found 34.1%. Cow\'s milk (98.9%) was the most common culprit food, followed by egg (47.3%), tree nuts (29.8%) and sesame (19.8%). The median age at tolerance was 7.1 months (6.9-9.1 months). The presence of atopic dermatitis (OR:3.325, 95%CI:1.025-10.783, p =0.045), presence of multiple food allergies (OR:4.489,95% CI:1.379-14.691 p =0.013), and initiation of complementary feeding after 5.5 months (OR:6.637,95% CI:2.025-21.755, p =0.002) were identified as risk factors for late tolerance.

Conclusion: Food protein-induced allergic proctocolitis is a benign and self-limiting condition due to the remission by the age of one year. The presence of atopic dermatitis, presence of multiple food allergies and initiation of complementary feeding after 5.5 months were risk factors for late tolerance.