Maxillary and ethmoid sinusitis may occur at any age. Frontal sinus infections first appear in adolescence. The bacteria that cause sinusitis are similar to those associated with otitis media. Streptococcus pneumoniae and Hemophilus influenzae are recovered from 50 to 70 percent of isolates. Anaerobes are also important pathogens in adults. Fungal sinusitis usually occurs only in diabetics or immunosuppressed individuals.