Are Management Strategies Associated with Tolerance Acquisition in Infants with Cow's Milk-Induced Allergic...

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.