the prevalence of fungal infections in nasal polyposis

for many years, it was thought that nasal polyps are small tumors of the nasal or sinus mucosa. however, it is now believed that nasal polyps are formed as a result of frequent local swelling of nasal or sinus mucosa, which enlarge by increasing sub-mucosal edema and then expose to the air pipe and cause some symptoms. however, the main cause of polyp formation is not exactly understood. the prevalence of disease is 1-4% of population. with increasing use of antibiotics, many fungi both saprophytes and pathogens are appeared in many diseases. we also cannot rule out the importance of fungal infections in large cities because of air pollution. in this study, attempts were made to investigate prevalence of fungal infections in nasal polyposis, and suggest suitable treatment in addition to the routine one. during 7 months, polyp samples from patients with nasal polyposis were collected. from the total amount of samples (50), both direct test with 10% koh and culture with sabouraud's dextrose agar were performed. in direct test, 42% of samples were positive for fungus. 34% of samples showed fungal colonization in culture, which include 30% aspergillus flavus and 4% aspergillus fumigatus. however, none of invasive fungi were found in pathological lamella. regarding to our results, it seems the high prevalence of fungal colonization in nasal polyposis may explain etiological factors, reasons of growth, increasing in numbers, and frequent recurrence of nasal polyps to some extent.