Changes in the clinical and histological characteristics of Chinese chronic rhinosinusitis with nasal polyps over 11 years

Traditionally, it was believed that chronic rhinosinusitis with nasal polyps (CRSwNP) demonstrated less eosinophilic and more neutrophilic inflammation in China compared to North America and Europe. However, inflammatory patterns may change over time. The study aimed to analyze the changing trends in the clinical and histological characteristics of CRSwNP over time in China.A total of 115 consecutive CRSwNP patients from 2003 to 2005 and 114 consecutive CRSwNP patients from 2014 to 2016 were enrolled in this retrospective study. The clinical and histological data were compared between patients from the 2 time periods.The percentage of eosinophils in nasal polyp tissue increased, and the percentage of neutrophils and total inflammatory cell count decreased, over 11 years. The proportion of eosinophilic CRSwNP significantly increased from 59.1% to 73.7% over 11 years. The proportion of neutrophils and the total inflammatory cell count in nasal polyps decreased, and the proportion of eosinophilic CRSwNP patients using intranasal corticosteroids 1 month before surgery increased remarkably over 11 years. Moreover, eosinophilic CRSwNP patients had better compliance with intranasal corticosteroid use than non-eosinophilic CRSwNP patients, and patients with comorbid allergic rhinitis and asthma had better compliance with intranasal corticosteroid use than patients without those conditions.Eosinophilic CRSwNP, which was previously a minor subtype in East Asians, has increased remarkably in incidence to become the predominant CRSwNP subtype in Beijing, China, indicating that rhinologists should place greater emphasis on its diagnosis and treatment.