Allergic fungal sinusitis: radiological and microbiological features of 59 cases

BACKGROUND AND OBJECTIVES: Allergic fungal sinusitis (AFS) is a relatively newly recognized entity consisting of a pansinusitis with allergic mucinous infiltrates in all involved sinuses. Historically mistaken for a paranasal sinus tumor, AFS is believed to be an allergic reaction to aerolized environmental fungi, usually of dematiaceous and Aspergillus species, in an immunocompetent host. We determined the occurrence of AFS in patients with chronic rhinosinusitis (CRS) to identify accurate preoperative parameters for AFS, as well as to identify the common fungi causing AFS in Saudi Arabia. METHODS: We conducted a retrospective chart review of 406 cases of CRS undergoing functional endoscopic sinus surgery from 2001 to 2005. Data regarding patient demographics, presenting symptoms, ENT examination, laboratory and radiological features, histopathological features and fungal culture was collected and analyzed. RESULTS: Fungal cultures were positive in 69 (16.9%) cases of CRS. Based on radiological features, histopathologic findings and culture results, AFS was diagnosed in 59 (14.5%) cases. Nasal polyposis was present in 56 (94.9%) cases; multiple sinuses were affected in all cases. Aspergillus species was the commonest causative fungal pathogen, being isolated in 40 (67.8%) cases, whereas dematiaceous fungi were isolated in 19 (32.2%) cases. CONCLUSIONS: AFS has been an underdiagnosed clinical entity. Only increased awareness among physicians of fungal involvement will increase accuracy of diagnosis.