Sinusitis is defined as an inflammation involving the membrane lining of any sinus, and is a frequent finding in HIV disease. In general, most acute sinusitis is a secondary bacterial complication of viral respiratory infections, which can cause decreased patency of the nasal ostia, decreased nasal ciliary action and increased mucus production.
Anaerobic pathogens are much more common in chronic sinusitis.
Staph aureus, Pseudomonas, and Aspergillus may be more common in immunosuppressed individuals. Most nasal congestion and drainage is due to chronic sinusitis. Patient complains of facial pain, headache, post-nasal drip, fever. CT scans are even more useful, but should not be done before standard films. Note that mucosal thickening is a very non-specific finding and does not necessarily mean infection.