ear, nose, and throat disorders
Sinusitis
Etiology of Sinusitis
. Immunocompromised patients may have acute invasive fungal sinusitis (see Invasive Sinusitis in Immunocompromised Patients ). Chronic sinusitisinvolves many factors that combine to create chronic inflammation. Chronic allergies, structural abnormalities (eg, nasal polyps), environmental irritants (eg, airborne pollution, tobacco smoke), mucociliary dysfunction, and other factors interact with infectious organisms to cause chronic sinusitis. The organisms are commonly bacterial (possibly as part of a biofilm on the mucosal surface) but may be fungal. Many bacteria have been implicated, including gram-negative bacilli and oropharyngeal anaerobic microorganisms; polymicrobial infection is common. In a few cases, chronic maxillary sinusitis is secondary to dental infection. Fungal infections (Aspergillus,Sporothrix,Pseudallescheria) may be chronic and tend to strike older and immunocompromised patients. Allergic fungal sinusitisis a form of chronic sinusitis characterized by diffuse nasal congestion, markedly viscid nasal secretions, and, often, nasal polyps. It is an allergic response to the presence of topical fungi, oftenAspergillus,and is not caused by an invasive infection. Invasive Sinusitis in Immunocompromised Patients None Common risk factors for sinusitis include factors that obstruct normal sinus drainage (eg, allergic rhinitis, nasal polyps, nasogastric or nasotracheal tubes, nasal packing) and immunocompromised states (eg, diabetes, HIV infection). Other factors include prolonged intensive care unit stays, severe burns, cystic fibrosis, and ciliary dyskinesia. 