IV.1. Upper airways: Allergic fungal rhinosinusitis (AFRS)
AFRS is a unique form of immune-mediated non-invasive fungal
rhinosinusitis exhibiting prominent Th2 responses, eosinophilic
inflammation, and IgE responses (78). Its prevalence is definitely
higher in arid and tropical climates, such as in the Asia-Pacific
region, Australia, Thailand, Malaysia, India, the Middle East, Saudi
Arabia, North Africa, and Southeastern and Southwestern parts of the US,
especially the Mississippi basin (79,80). Climate influence is
prominent, as demonstrated by a prevalence of 0.4% in Northern US
states compared to over 10% in Southern ones. A. fumigatus is
the most frequent fungus involved in AFRS (4,79,80).