Chronic rhinosinusitis: An enhanced immune response to ubiquitous airborne fungi

Fungal flora in the trachea of birds from a wildlife rehabilitation centre in Spain

“…Airborne fungal spores, e.g. Aspergillus, enter the upper and lower respiratory tract by inhalation, but are rarely pathogenic in healthy individuals (Shin et al, 2004). The ubiquity of the organism suggests that birds may be carriers of the fungi but do not develop overt disease unless stimulated by a decreased resistance of the host elicited by some stress such as an infectious disease, a toxicant, or malnutrition.…”

“…Most of them are caused by ubiquitous microorganisms to which birds, just like humans and other animals, are continually exposed (Shin et al, 2004). In these processes, members of the genera Aspergillus and Candida are the most frequently isolated pathogens (Bauk, 1994;Cork et al, 1999;Hubalek, 2004).…”

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.…”

“…In Ferguson's experience, patients with eosinophilic mucinous rhinosinusitis were clinically different from allergic FRS patients including presentation at an older age, an association with asthma and a significantly higher risk of aspirin sensitivity syndrome. However, eosinophilic mucinous rhinosinusitis as a distinct entity has been called into questioned by those that feel that sensitive methods to evaluate for fungus have not been applied fully to these patients [20,21,26,29]. Guo et al [34] using conventional Gomori methenamine silver stain (GMS) on eosinophilic mucin observed fungal organisms in only 27 % of specimens; however with trypsin pre-digestion followed by GMS, the yield was increased to 91 % of specimens.…”

“…However, not all patients with the pathologic diagnosis of allergic FRS have systemic (or even local) hypersensitivity to fungi. More recent studies indicate that fungi induce production of eosinophil attracting T h 2 cytokines and the subsequent inflammatory reaction produced results in the formation of allergic mucin [7,17,18,20,29]. Fungal proteases can induce the production of cytokines attract an influx of inflammatory cells including eosinophils which migrate through the barrier epithelial cells in response to fungi present.…”