Yu-Han Wang

Background and Objectives: Chronic rhinosinusitis (CRS) frequently recurs following endoscopic sinus surgery (ESS), yet reported recurrence rates, risk factors, and treatment responses differ significantly across regions. This review aims to synthesize current evidence on recurrence patterns, predictive models, and treatment strategies, with a focus on comparing Asian and Western populations. Materials and Methods: A structured narrative review was conducted by searching PubMed, Embase, and Cochrane Library from January 2010 to June 2025. A total of 116 studies were included based on predefined criteria regarding recurrence definitions, risk factors, prediction models, and postoperative management. Results: Recurrence rates ranged from 12% to 76.6%, with wide variability attributed to differences in follow-up duration and recurrence definitions. Key risk factors included tissue eosinophilia, comorbid asthma, and type 2 inflammation. Asian predictive models emphasized inflammatory biomarkers such as tissue and blood eosinophils, whereas Western models incorporated imaging, prior surgical history, and symptom burden. While biologics are widely used in the West, their adoption remains limited in Asia, where endotype-driven corticosteroid strategies are predominant. Conclusions: CRS recurrence after ESS is influenced by inflammatory endotypes, comorbidities, and regional treatment paradigms. Cross-regional differences in immune profiles and healthcare access necessitate the development of standardized definitions and validated, endotype-driven prediction tools. Tailored treatment strategies, especially for non-type 2 CRS, are essential to achieving equitable and effective care globally.

Some individuals with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) experience anosmia, or loss of smell. Although the prevalence of anosmia has decreased with the emergence of the Omicron variant, it remains a significant concern. This review examines the potential role of polyunsaturated fatty acids (PUFAs), particularly omega-3 PUFAs, in treating COVID-19-induced anosmia by focusing on the underlying mechanisms of the condition. Omega-3 PUFAs are known for their anti-inflammatory, neuroprotective, and neurotransmission-enhancing properties, which could potentially aid in olfactory recovery. However, study findings are inconsistent. For instance, a placebo-controlled randomized clinical trial found no significant effect of omega-3 PUFA supplementation on olfactory recovery in patients with COVID-19-induced anosmia. These mixed results highlight the limitations of existing research, including small sample sizes, lack of placebo controls, short follow-up periods, and combined treatments. Therefore, more rigorous, large-scale studies are urgently needed to definitively assess the therapeutic potential of omega-3 PUFAs for olfactory dysfunction. Further research is also crucial to explore the broader role of PUFAs in managing viral infections and promoting sensory recovery.