Are Management Strategies Associated with Tolerance Acquisition in Infants with Cow’s Milk-Induced Allergic Proctocolitis?

Background: Food protein-induced allergic proctocolitis (FPIAP) is generally considered a benign and self-limited condition; however, both its natural course and the impact of management strategies on prognosis remain controversial. Data on modifiable factors influencing tolerance acquisition are limited. Methods: We conducted a retrospective cohort study including 180 infants with cow’s milk-induced FPIAP. Clinical characteristics, management strategies, and outcomes were analysed. Logistic regression was used to identify factors associated with delayed tolerance, and Kaplan–Meier and Cox regression analyses were performed to evaluate time to tolerance. Results: Tolerance was achieved in 91.2% of infants, with a median time from diagnosis to tolerance of 31.1 weeks. In multivariable logistic regression, multi-food elimination at presentation (OR, 2.58; 95% CI, 1.02–6.54; p = 0.046) and a longer interval from diagnosis to reintroduction (OR per week, 1.08; 95% CI, 1.02–1.14; p = 0.022) were independently associated with delayed tolerance. Exclusive breastfeeding was associated with lower odds of delayed tolerance in univariable analysis but not after adjustment. In unadjusted time-to-event analyses, observation-first management was associated with earlier tolerance acquisition (HR, 0.37; 95% CI, 0.22–0.62; p < 0.001), whereas multiple food allergy was associated with a lower probability of tolerance acquisition over time (HR, 0.60; 95% CI, 0.41–0.88; p = 0.009). Feeding modality also showed an unadjusted temporal association with tolerance acquisition, with exclusively breastfed infants demonstrating a more favorable pattern than formula-fed infants. Conclusions: The course of FPIAP appears to be influenced not only by clinical characteristics but also by management strategies. Delayed reintroduction and multi-food elimination were associated with later tolerance, while observation-first management was associated with earlier tolerance acquisition. These findings suggest that commonly used strategies such as prolonged elimination or delayed reintroduction may warrant reconsideration in selected infants and support a more individualized and less restrictive approach to management.