Microbiology of acute and chronic sinusitis in children.

To determine the bacteriologic cause of acute sinusitis, a sample of sinus secretions must be obtained from one of the paranasal sinuses without contamination by normal respiratory or oral flora that colonize mucosal surfaces. When maxillary sinus aspiration is performed on children who have signs and symptoms of acute sinusitis, bacteria are recovered in high density from 70%. In patients with acute, subacute, or chronic sinusitis who are generally well except for persistent respiratory symptoms, of nasal discharge or cough or both, the usual bacterial isolates are Streptococcus pneumoniae, Haemophilus influenzae, an Moraxella catarrhalis. In contrast, anaerobic organisms and staphylococci should be suspected in patients who have very long-standing symptoms or in those whose symptoms are so severe or complicated that sinus surgery is undertaken.