This study aims to evaluate the efficacy and safety of multi-food oral immunotherapy (multi-OIT) using peanut and tree nuts proteins in children with confirmed food allergy to at least two allergens. Participants will be randomized in a 2:1 ratio to receive either multi-OIT or standard management consisting of an elimination diet. The primary objective is to evaluate immunotherapy efficacy defined as achieving tolerance to a cumulative dose of 4444 mg of protein during an oral food challenge (OFC-2) for at least one allergen that elicited a reaction during baseline challenge (OFC-1), compared with the control group. Secondary outcomes include the proportion of participants tolerating multiple allergens at the target cumulative dose; the incidence, type, and severity of adverse events classified according to the World Allergy Organization (WAO) grading system; changes in immunological parameters, including allergen-specific IgE and IgG4 levels; changes in skin prick test responses; changes in the quality of life of patients and their families.