Twelve-month growth and accession of tolerance in infants with cow's milk protein allergy compared among those fed with breast milk or alternative formulae.

Background: Cow's milk protein allergy (CMPA) is a common food allergy in children. The impact of various feeding regimens on growth in infants with CMPA is not sufficiently well understood.

Objective: To investigate 12-month growth and accession of tolerance in infants with CMPA compared among those fed with breast milk or alternative formulae.

Methods: This retrospective study included CMPA infants with treatment adherence for at least six months. Infants were categorized into the following feeding regimen groups: soy-based formula (SF), extensively hydrolyzed protein formula (EHF), commercial amino acid-based formula (cAAF), new amino acid-based formula (nAAF), chicken-based formula, and breast milk. Weight-for-age z-score (WAZ), length-for-age z-score (LAZ), and weight-for-length z-score (WLZ) were evaluated at diagnosis and at follow-ups. Clinical manifestations, other allergenic foods, and time to tolerance of CMP were assessed.

Results: One hundred and sixteen infants were enrolled. Infants consuming EHF had markedly improved WAZ. Infants with one symptom at diagnosis, those who had gastrointestinal symptom, and those with allergy to only CMP had more pronounced growth improvement. Compared to breast milk, SF and EHF were significantly associated with lower probability of tolerance to CMP (HR: 0.14, 95%CI: 0.03-0.62; and, HR: 0.21, 95%CI: 0.07-0.64, respectively). Those allergic to only CMP were more likely to develop tolerance to CMP than those allergic to CMP and other foods.

Conclusions: Improvement in growth was significantly more pronounced in CMP-allergic infants fed with EHF. Accession of tolerance to CMP was associated with breast milk as the therapeutic diet.