The mold conundrum in chronic rhinosinusitis: Where do we stand today?

Abstract

Chronic rhinosinusitis (CRS) is an inflammatory disorder affecting the nose and paranasal sinuses. Although bacteria have long been implicated as pathogens in most forms of CRS, fungi may be responsible for some forms. Several recent studies demonstrated that, under optimal conditions, fungi can be identified in the nose and paranasal sinuses of nearly every individual (including all CRS patients). An aberrant immune response to these ubiquitous fungi has been suggested to explain the development of CRS in some individuals. Several mechanisms requiring additional research, including adequate controls, have been proposed and are reviewed in this article. Although preliminary trials suggested that CRS signs and symptoms improve upon treatment with topical and oral antifungal agents, several double-blind, placebo-controlled trials demonstrated the contrary. In the absence of convincing immunologic data and evidence of clinical improvement upon therapy with antifungal agents, the case against fungi remains unproven.

Pathology of Fungal Rhinosinusitis: A Review

“…2, 3). Eosinophilic mucin is now the preferred term instead of allergic mucin since there is debate regarding whether the etiology of this mucinous material, as well as allergic FRS, is allergic at all [1,2,17,18,[20][21][22][23][24][25][26][27][28][29]. Fungal hyphae are occasionally seen on H and E stain but are best highlighted by histochemical stains such as silver or periodic acid Schiff (PAS) (Fig.…”

The Etiology and Pathogenesis of Chronic Rhinosinusitis: a Review of Current Hypotheses

“…Secondly, two separate attempts to replicate the sensitization of PBMCs to fungal antigens in CRS patients failed, indicating that the original findings were clearly not universal [22, 23]. Third and most importantly, double-blind, placebo-controlled trials involving antifungal agents failed to show any evidence of efficacy in modifying the disease process of CRS [24, 25]. Follow-up studies on the mucus of CRS patients treated with topical amphotericin also failed to show effects on any relevant CRS-related cytokine or chemokine [26].…”

In response to the Effect of Topical Amphotericin B on Inflammatory Markers in Patients with Chronic Rhinosinusitis: A Multicenter Randomized Controlled Study

“…10,11 We agree that further studies are necessary to clarify the exact role of fungi in CRS pathogenesis, to assess which fungal organisms, if any, are pathogenic, and what exactly characterizes the immunological response to fungi that may potentially result in the development of disease. Presently, in the absence of convincing microbiological and immunological data or evidence of effectiveness of both topical and oral antifungals, we feel that the case against the fungus remains unproven.…”