The effect of formula type on the prognosis of allergic proctocolitis due to cow's milk allergy.

Background: Food protein-induced allergic proctocolitis is a nonimmunoglobulin E-mediated, self-limited food allergy of the rectum and the colon. Cow's milk protein is the most common allergen responsible for the disease.

Objective: This study aimed to investigate the roles of different types of formulas in building early tolerance to food protein-induced allergic proctocolitis in infants.

Methods: The medical records of 45 pediatric patients diagnosed with proctocolitis due to cow's milk allergy between August 2021 and August 2023 and whose disease progression was followed in three tertiary care centers were reviewed retrospectively.

Results: The study included 45 patients who were diagnosed with proctocolitis due to cow's milk allergy (24 males, 21 females; median age: 4 months). Among them, 24 patients were fed an amino acid-based formula, and 21 (46.7%) patients were fed an extensively hydrolyzed formula. The average age of acquisition of cow's milk tolerance was lower in the group fed with the amino acid-based formula than in the group fed with extensively hydrolyzed formula (P = 0.038). Furthermore, the group fed with amino acid-based formula had a shorter tolerance period than the group fed with the extensively hydrolyzed formula group (P = 0.044).

Conclusion: Compared to an extensively hydrolyzed formula, an amino acid-based formula led to the early development of tolerance in children with allergic proctocolitis induced by cow's milk.