Background: Food protein-induced allergic proctocolitis (FPIAP) is a food allergy characterized by bloody stools in well-appearing breast-fed infants.
Objective: To determine the clinical course of FPIAP and the factors affecting the development of tolerance.
Methods: Over a 10-year period, patients with a diagnosis of FPIAP who were followed at the outpatient Allergy-Immunology clinic in a tertiary care children's hospital in Turkey were retrospectively analyzed.
Results: The frequency of FPIAP was 0.18% among 64,549 patients. The median age of symptom onset was 2 months (interquartile range, 1.0-3.5 months), and the median age of tolerance development was 12 months (interquartile range, 8.0-17.21 months). The occurrence of symptoms in the neonatal period was associated with a history of premature birth (odds ratio, 3.75; 95% CI, 1.33-10.59; P = .031) and neonatal intensive care unit hospitalization (odds ratio, 4.72; 95% CI, 1.78-12.53; P = .002). Use of a cow's milk-based formula was associated with a higher risk of the onset of symptoms after 1 month (odds ratio, 2.69; 95% CI, 1.19-6.07; P = .016). The use of an amino acid-based formula and the presence of diarrhea at admission were associated with later development of tolerance (P = .023 and P < .001, respectively). An IgE-mediated reaction was observed during oral food challenge testing in 6% of the patients.
Conclusions: The manifestations of FPIAP appeared earlier in premature infants and later in infants using formula. The use of amino acid-based formula and having had diarrhea were associated with delayed tolerance.
Keywords: Bloody-mucus stool; Diarrhea; Food protein–induced allergic proctocolitis; Infant; Tolerance.
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