Kwah JH, Somani SN, Stevens WW, et al. - Researchers undertook this retrospective cohort analysis to explore clinical factors related to frequent acute exacerbation of chronic rhinosinusitis (CRS) [AECRS]. The definition of frequent AECRS comprised at least 4 episodes over a 12-month span in which an antibiotic was prescribed for worsening sinus symptoms. They defined infrequent AECRS as 0 to 3 episodes. Findings revealed a higher prevalence of asthma, allergic rhinitis, eosinophil count of at least 150 cells per microliter, autoimmune disease, and other allergic and immunologic diseases as the characteristics of patients who frequently encountered AECRS. A high-risk phenotype of patients with CRS was defined for preventive strategies to decrease exacerbation frequency.