Role of fungi in pathogenesis of chronic rhinosinusitis: The hypothesis rejected

Purpose of review: Fungi have been suggested to play an important role in the pathogenesis of chronic rhinosinusitis (CRS). This review describes the recent knowledge concerning the role of fungi in the pathogenesis of CRS and allergic fungal rhinosinusitis (AFRS) and the clinical implications for treatment. Recent findings: Recent studies show that, although there are several potential deficits in the innate and potentially also in the acquired immunity of CRS patients that might reduce or change their ability to react to fungi, there are not many arguments to suggest a causative role for fungi in CRS with or without nasal polyps. However, due to the intrinsic or induced change in immunity of CRS patients, fungi might have a disease-modifying role. The fact that AFRS is more prevalent in warm and humid areas may point to fungi as a factor in this disease. Summary: Almost a decade after the launching of the hypothesis by Ponikau, the absence of convincing immunological data or evidence for clinical improvement of CRS upon therapy with antifungal agents now means that the hypothesis that fungi play a role in a majority of the cases of CRS has to be rejected and antifungal treatment should not be used.