What is identified as the most common cause of infectious fungal sinusitis?

Aspergillus fumigatus is identified as the most common cause of infectious fungal sinusitis primarily because it is a ubiquitous environmental mold that frequently exists in soil, decaying matter, and indoor environments. This mold is an opportunistic pathogen, meaning that it typically causes disease in individuals who have compromised immune systems, such as those with uncontrolled diabetes, prolonged corticosteroid use, or other immunosuppressive conditions.

In patients with healthy immune systems, Aspergillus species can occasionally cause conditions like allergic fungal sinusitis, but more commonly, it leads to invasive sinusitis in those who are immunocompromised. The characteristics of Aspergillus fumigatus, such as its ability to form airborne spores that can be inhaled, contribute significantly to its prevalence as a causative agent in these infections, especially in populations at risk.

The other listed fungal pathogens are less commonly associated with sinusitis. While Candida albicans can cause infections, its primary association is with mucosal and systemic infections rather than particularly prevalent sinus infections. Mucor species, while they can cause rhinocerebral mucormycosis in severely immunocompromised patients, are not the most common cause of isolated fungal sinusitis. Cryptococcus neoformans typically causes