Allergic fungal rhinosinusitis (AFRS) is a noninvasive type of fungal rhinosinusitis (FRS) that is diagnosed by fulfilling five diagnostic criteria: type I hypersensitivity, nasal polyposis, characteristic findings on CT scan, presence of fungi on direct microscopy or culture, and allergic mucin containing fungal elements. Objectives: This work aimed to study the fungal etiology of AFRS and to evaluate the prevalence of AFRS among patients with CRS with nasal polyposis (CRSwNP) that underwent endoscopic sinus surgery (ESS) at Sohag University Hospital. Patients and Methods: A prospective study involved all patients presented to Otorhinolaryngology Department, Sohag University Hospital, Sohag, Egypt, with nasal polyposis and who were candidate for ESS during the period from December 2015 to December 2016. A detailed history was taken, full E.N.T examination and CT scans were done to all patients who underwent ESS. Histopathological examination of the removed polyps and eosinophilic allergic mucin (AM) was done using hematoxylin& eosin (H&E), periodic Acid schiff (PAS) and Gomorimethanamin silver (GMS) stains.Statistical analysis was carried out with the Statistical Software Package Standard (SPSS). Results: In 17/61 patients, AM was detected, 12/61 of them (19.7%) showed no fungal hyphae and were diagnosed eosinophilic mucinrhinosinusitis (EMRS). In the remaining 5/61 (8.2%) cases AM and fungal hyphae were seen and diagnosed as AFRS. 41/61 (67.2%) patients didn't show neither AM nor fungal hyphae and diagnosed as CRSwNP. In 2/61 (3.3%) we detected fungal hyphae both on the surface of polyp mucosa and invading the tissue of the nasal polyps and diagnosed as chronic invasive fungal rhinosinusitis (CIFRS) and the remaining one patient (1/61=1.6%) was diagnosed to have inverted papilloma. Conclusion: No significant association between AM and fungal hyphae, only 5/17 (P=0.09) patients with AM fulfill the diagnostic criteria of AFRS. The presence of AM is not unique to AFRS, but rather is the result of a process that could have other etiologies. AFRS is more appropriately termed allergic mucinous sinusitis or eosinophilic mucinous rhinosinusitis.
Keywords: fungus; nasal polyp; prevalence; sinusitis.