Fungus as the cause of chronic rhinosinusitis: the case remains unproven.

Purpose of Review: To review the literature on the role of fungi in chronic rhinosinusitis (CRS) pathogenesis and the effect of antifungal drug therapy and antifungal immunotherapy.
Recent Findings: This paper reviews the most recent articles investigating the role of fungi in CRS pathogenesis. In addition to possible aberrant innate and adaptive antifungal immune responses and fungus antihost effects, which all may explain disease development, the effect of antifungal drug therapy and antifungal immunotherapy is reviewed.
Summary: Although fungi can be detected in the nose and paranasal sinuses of nearly all patients with CRS and are present in almost all healthy controls, various studies suggest that there may be mechanisms by which fungi exert an effect on sinus mucosa in susceptible individuals only. Future studies will have to clarify the role of fungi in CRS, which fungal organisms, if at all, may be pathogenic and what exactly characterizes the immunological response to fungi that potentially results in the development of disease. Presently, in the absence of convincing immunological data and evidence for clinical improvement of CRS upon therapy with antifungal agents, the case against the fungus remains unproven.