Marco Caminati

Adherence to treatment is essential in chronic rhinosinusitis with nasal polyposis (CRSwNP). Intranasal corticosteroids (INCS) are the first-line therapy, followed by systemic corticosteroids and surgery if needed. In cases of refractory disease, biologics are added to conventional treatment, making adherence to INCS crucial in assessing eligibility for these targeted therapies. The purpose of this review is to examine INCS adherence assessment and rate, before starting and during biologic therapy. We conducted a comprehensive literature review focusing on INCS adherence in CRSwNP treated with biologics, including randomized controlled trials and real-life studies. The search extended to studies on allergic and non-allergic rhinitis to provide broader insights into tools to assess the INCS adherence. The result was that adherence to INCS in CRSwNP is underexplored, with only a few studies addressing it directly. Various tools for adherence assessment have been identified, but none are universally accepted as standard. The review also highlights the complexity of factors influencing adherence rates. Effective CRSwNP management requires a paradigm shift to prioritize adherence in treatment guidelines and clinical practice. The review advocates for improved adherence assessment tools, a deeper understanding of influencing factors, and the integration of personalized medicine approaches, especially for biologic therapies.