Gastrointestinal manifestations of food allergy in infants: clinical forms, diagnostics, and prognosis

Background. Cow’s milk protein (CMP) allergy is the most prevalent form of food allergy in infants, with a prevalence of up to 4.9 %. The nonspecific symptoms of non-IgE-mediated gastrointestinal forms (proctocolitis, enterocolitis, and enteropathy) complicate timely diagnosis and therapy. Objective. This study aimed to investigate the clinical and morphological characteristics of gastrointestinal food allergy to CMP in early childhood, assess age-specific manifestation patterns, diagnostic accuracy, and elimination diet efficacy, and identify prognostic factors for tolerance development. Materials and methods. A retrospective analysis of infants aged 2 weeks to 2 years with confirmed non-IgE-mediated CMP allergy was conducted. The diagnostic workup included clinical history, stool clinical analysis (with fecal calprotectin), skin tests, and intestinal mucosa biopsies. The effectiveness of the therapeutic (infant) formula as part of the elimination strategy was evaluated. Results. Three main forms were identified: FPIAP (manifestation at 2–6 weeks), FPIES (before 3 months), and FPE (after 4 months), each with specific clinical and morphological features. The therapeutic (infant) formula demonstrated 98.4 % clinical efficacy, leading to symptom resolution, weight gain normalization, and mucosal recovery. CMP tolerance developed in most infants by age 3 for FPIAP and FPIES and by age 5 for FPE. Conclusions. Non-IgE-mediated gastrointestinal CMP allergy with age-dependent clinical profiles in infants. Elimination therapy using extensively hydrolyzed formula yields high efficacy in symptom resolution and promotes earlier acquisition of tolerance.