Sinus aspergillosis and allergic fungal sinusitis.

Aspergillosis of the sinonasal tract has four basic clinicopathologic presentations depending on the mucosal or extramucosal involvement by the fungus. Two are saprophytic (aspergilloma and allergic Aspergillus sinusitis) and two are infectious (chronic indolent and invasive fulminant sinusitis). Tissue-invasive and angioinvasive aspergillosis can be a rapidly lethal disease, particularly in the immune-compromised host. The allergic form of paranasal sinus aspergillosis is presumed to be initiated by hyperreactivity to fungal antigens. Not all allergic fungal sinusitis is associated with Aspergillus species, and culture confirmation is necessary to distinguish the fungal agent. Surgical removal of the offending fungus is the mainstay of therapy in all forms of sinonasal aspergillosis and other fungal sinusitis. Antifungal agents and steroids complement surgical removal, depending on the form of the sinusitis.