Abstract
Pediatric asthma and allergic rhinitis are prevalent chronic inflammatory diseases ruled by complex interactions among genetic, environmental, and nutritional factors. Zinc, an essential trace element, plays a crucial role in immune modulation, oxidative stress regulation, and epithelial barrier maintenance, all of which are significant in the context of allergic airway diseases. This review aimed to explore and synthesize current evidence on the biological mechanisms and clinical implications of zinc in pediatric asthma and allergic rhinitis. A comprehensive literature search was conducted through PubMed and the Cochrane Library for studies published between 2015 and 2025. Eligible studies included observational and interventional research focused on zinc status or supplementation in children with asthma or allergic rhinitis. Numerous observational studies and meta-analyses indicated reduced circulating zinc levels in children with asthma, often correlating with poor symptom control, increased oxidative stress, and lower pulmonary function. In allergic rhinitis, zinc depletion in nasal mucosa was associated with elevated local inflammation, although paradoxical increases in zinc concentrations have been observed in nasal secretions during active disease. Interventional trials in pediatric asthma populations showed that zinc supplementation may improve clinical symptoms, reduce inflammation, and enhance lung function, although the results were inconsistent and limited by methodological variability. In conclusion, zinc plays a multifactorial role in modulating immune responses and maintaining mucosal health in pediatric allergic airway diseases. While zinc supplementation holds promise as a safe and accessible adjunctive therapy, further high-quality randomized controlled trials are needed to define its clinical utility and establish evidence-based guidelines.