Clinical characteristics and pathogen spectrum of patients with fungal rhinosinusitis and risk factors for invasiveness in Northern China: a retrospective study (2015–2024)

Abstract Background Fungal rhinosinusitis (FRS) is becoming increasingly common but remains underdiagnosed or misdiagnosed due to atypical symptoms in invasive cases and limited regional epidemiological data. The aim of this study was to systematically describe the pathogenic spectrum, clinical characteristics, and risk factors for invasive disease in patients with FRS in Northern China over the past decade. Methods This retrospective study included 511 patients diagnosed with FRS at a tertiary hospital in Northern China from January 2015 to December 2024. All cases were confirmed by histopathology and fungal culture. Patients were classified as invasive fungal rhinosinusitis (IFRS) or non-invasive fungal rhinosinusitis (NIFRS) based on histopathological evidence of tissue invasion. Demographic characteristics, clinical manifestations, underlying diseases, laboratory findings, and pathogen data were collected and analyzed. Multivariate logistic regression was used to identify independent risk factors for IFRS. Results Among 511 patients, 52 (10.2%) were classified as IFRS and 459 (89.8%) as NIFRS. Chronic infection predominated (93.3%), with the maxillary sinus being the most frequently involved site (86.7%). Aspergillus species were the predominant pathogens (64.6%), primarily Aspergillus fumigatus (25.8%) and Aspergillus flavus (25.6%). Bacterial co-infection was present in 47.2% of patients. Compared to NIFRS, IFRS patients had significantly higher frequencies of ocular symptoms (50.0% vs. 16.1%, P < 0.001) and nasofacial swelling (34.6% vs. 14.6%, P < 0.001), but lower frequencies of nasal obstruction and rhinorrhoea (44.2% vs. 80.2%, P < 0.001). The detection rate of Mucorales was significantly higher in IFRS (9.6% vs. 0.9%, P < 0.001). Multivariate analysis showed that diabetes mellitus was independently associated with IFRS (OR = 5.187, 95% CI : 2.576–10.446, P < 0.001). Subgroup analysis revealed distinct clinical and pathological profiles between acute and chronic IFRS. Conclusions FRS in Northern China is predominantly chronic and Aspergillus-driven. Ocular symptoms and nasofacial swelling are critical warning signs of invasive disease, and diabetes mellitus was independently associated with IFRS. Clinicians should maintain a high index of suspicion for IFRS in diabetic patients presenting with atypical symptoms to enable early diagnosis and timely intervention.