Acute exacerbations of chronic rhinosinusitis: The current state of knowledge.

Objectives: Acute exacerbations of chronic rhinosinusitis (AECRS) are distinct from baseline symptomatology related to chronic rhinosinusitis (CRS). In this review, we seek to examine the literature on AECRS to synthesize the definition, epidemiology, pathophysiology, treatment, and impact of AECRS on CRS patients. Methods: A comprehensive narrative review of the scientific literature, identified by searching PubMed from inception through April 2022, was performed. Results: AECRS is defined in consensus guidelines as a worsening of chronic sinus disease symptomatology, with a return to baseline, typically after intervention with systemic antibiotics and/or corticosteroids. The working definition used across the literature, however, is broad and heterogeneous. The pathophysiology of AECRS is incompletely understood but is hypothesized to include an interplay of environmental and patient-specific factors. AECRS have been found to have a negative impact on quality-of-life measures, independent of baseline CRS symptomatology, and impact how patients and physicians view overall disease control. Treatment for AECRS includes oral antibiotics and systemic corticosteroids, although their efficacy for AECRS is unclear. Appropriate use of medical and surgical treatment for CRS can reduce the frequency of AECRS. Conclusions: AECRS are a distinct entity in CRS patients and should be independently assessed when evaluating patients for CRS control. The efficacy of systemic medication usage for AECRS is currently unclear, but appropriate medical management of baseline CRS can reduce the frequency of AECRS. More research is needed to further understand this phenomenon, including a more precise and prospective definition, defined epidemiology, and how to appropriately treat. Level of Evidence: 5.