Abstract Background Evidence on the effectiveness of partially hydrolyzed formulas (pHF) as a nutritional intervention to prevent Allergic Manifestations (AM) is limited. Provided that not all pHF are the same in terms of allergenicity and immunogenicity, their role in reducing the risk of the Atopic March progression should be individually and longitudinally examined. Objective To investigate whether the risk‐reduction effect of a specific pHF compared to a standard formula (SF) on Atopic Dermatitis (AD) within the first 6 months of life observed in the Allergy Reduction Trial (A.R.T.) persists at the age of 5 years and, if it applies to other AM. Methods Parents/legal guardians of participants within the multicenter double‐blinded randomized controlled clinical Allergy Reduction Trial (A.R.T.) who constituted the Intention‐to‐Treat population set ( N = 551) were invited at the age of 5 years for an observational follow‐up, to answer an enriched validated questionnaire regarding doctor diagnosis of AM between 1 and 5 years of age, including AD, Food Allergy (FA), Asthma, and Allergic Rhinitis (AR). The prevalence and cumulative incidence of outcomes were calculated and Relative Risks, 95% Confidence Interval (RR, 95% CI) were estimated by Poisson Generalized Estimating Equations adjusted for study center, sex, family history of AD, family history of AR, family history of Asthma, and mode of delivery. Results Four hundred and fifty‐five subjects (83%) completed the 5‐year follow‐up (pHF: 131/160, SF: 145/171 and EBF: 179/220). The RR from birth to 5 years was significantly lower in the pHF group, for the development of any AM 32.7% vs. 51.7%, RR 0.73 (0.57–0.94), p = .02, AD 22.1% vs. 38.5%, RR 0.58 (0.41–0.83), p = .003 and, FA 10.5% vs. 20.4%, RR 0.53 (0.29–0.95), p = .03 compared to the SF group. Infant feeding with the pHF resulted in 87% risk‐reduction of FA 1.5% vs. 12.4%, RR 0.13 (0.03–0.58), p = .007 between the ages of 1–5 years. Conclusion In non‐exclusively breastfed infants at high‐risk for allergy, mixed‐feeding with a specific whey‐based pHF during the first 6 months of life may reduce the risk of atopic dermatitis and food allergy from birth up to the age of 5 years. However, further A.R.T. follow‐ups and other longitudinal studies with larger sample size are needed to provide additional evidence for the long‐term effectiveness of pHF in allergy prevention.
Sekkidou et al. (Fri,) studied this question.