Sinusitis as a cause of orbital cellulitis

To determine the importance of sinusitis as a cause of orbital cellulitis, the causative organisms and peak age of occurrence, 25 patients hospitalized with orbital cellulitis (ages 8 months to 17 years; 80%, 1-4 years) were studied. Complete blood counts were carried out and radiographic sinus examinations and eye swabs (for culturing) performed prior to antibiotic treatment. Sinusitis was evident in 72% of the patients. Eye swab cultures indicated 80% had streptococcal, staphylococcal or enterococcal infection. The data indicate that sinusitis is an important cause of orbital cellulitis. The most common causative organisms were Streptococcus viridans (44%) and Staphylococcus aureus (32%). Initial antibiotics should therefore cover both organisms.