Background: Asthma is a major public health problem that affects nearly 350 million people worldwide. It is also the most common chronic disease in childhood and adolescence.Several asthma phenotypes and endotypes have been identified. While 80% of children with asthma have allergies.In recent years, studies on the role of periostin in asthma have been published.Periostin is a cell matrix protein that was first identifid in mouse periodontal ligament. It is secreted by bronchial fibroblasts and epithelial cells, acts as an immunomodulator, repairs connective tissue, and is involved in fibrogenesis. Significant periostin expression has been noted in the bronchial epithelial cells of children with asthma.