Allergic rhinitis (AR) is a common disease around the world, mediated by type 2 immune responses, and some patients don’t respond well to current standard treatments. This shows AR isn’t a single type of disease but a complex syndrome caused by different internal body mechanisms. Periostin is a key matrix protein sitting downstream of the interleukin-4 (IL-4) and interleukin-13 (IL-13) pathways, connecting type 2 immune responses and nasal mucosal tissue remodeling. This article explains periostin’s many roles in AR: it breaks down the epithelial barrier, makes eosinophils gather, and causes fibrosis, and these things form a never-ending “inflammation-repair” vicious cycle. In clinical use, periostin levels in different biological samples matter—they relate to how severe the disease is and show how patients respond to glucocorticoids and biologics. Targeting periostin directly might offer new ways to help with hard-to-treat tissue remodeling. Based on these findings, we suggest a way to classify AR using periostin levels, which aims to guide personalized treatment in the future and help AR diagnosis and therapy become true precision medicine.