RT Book, Section A1 Chan, Yvonne A1 Goddard, John C. SR Print(0) ID 1172370297 T1 Chronic Rhinosinusitis T2 K.J. Lee’s Essential Otolaryngology: Head and Neck Surgery, 12e YR 2019 FD 2019 PB McGraw-Hill Education PP New York, NY SN 9781260122237 LK accesssurgery.mhmedical.com/content.aspx?aid=1172370297 RD 2024/03/29 AB Chronic rhinosinusitis (CRS) is defined as symptomatic inflammation of the paranasal sinuses and nasal cavity for a duration longer than 12 weeks.To make a diagnosis of CRS, two or more of the following cardinal symptoms must be present for 12 weeks or longer:Mucopurulent drainage (anterior or posterior)Nasal obstruction/congestionFacial pain or pressureHyposmia or anosmiaIn addition to documentation of two or more of the above symptoms, inflammation of the nasal mucosa must be confirmed by one of the following findings:Polyps in the nasal cavity or middle meatus, confirmed with endoscopy or anterior rhinoscopyPurulence or edema in the middle meatus or anterior ethmoid cavityRadiographic (CT) evidence of mucosal thickening, edema, or other findings consistent with inflammationCRS can be punctuated by acute exacerbations, sometimes referred to as “acute-on-chronic” rhinosinusitis, in which symptoms worsen secondary to an acute infection or other environmental insult.Subacute rhinosinusitis historically referred to symptoms lasting between 4 and 12 weeks, although recent guidelines have only made diagnostic and treatment distinctions between acute and CRS.Recurrent acute sinusitis refers to four or more discrete episodes of sinusitis in one year, with asymptomatic periods between episodes, and is treated differently from CRS.