Sinogenic orbital and subperiosteal abscesses: microbiology and methicillin-resistant Staphylococcus aureus incidence

To assess the current bacteriology and the incidence of methicillin-resistant Staphylococcus aureus in orbital and subperiosteal abscesses of paranasal sinus disease origin.

Case series with chart review.

An otolaryngology and ophthalmology specialty hospital.

Fifty-three patients were treated between 1994 and 2008 for orbital or subperiosteal abscess and paranasal sinusitis, confirmed by imaging and surgical intervention; 46 had operative culture specimens and comprise the study cohort.

The mean patient age was 28 years; one third were younger than 18. Nearly twice as many patients had subperiosteal (n = 30) as had orbital abscesses (n = 16). In 12 patients (26%), cultures were negative or grew only skin flora contaminants (coagulase-negative staphylococci, diphtheroids, and Propionibacterium acnes). Fifteen patients (33%) grew more than one pathogen. Streptococci were isolated in 17 of the 46 cases (37%), S. aureus in 13 (28.3%), gram-negative bacilli in eight (17.4%), and anaerobes in nine (19.6%). Methicillin-resistant S. aureus accounted for three (23.1%) of the S. aureus isolates and 6.5 percent of the total cases.

Abscess cultures grew a mixture of bacteria, including gram-positive cocci, gram-negative bacilli, and anaerobes. Although streptococci were the most common genus of bacteria isolated, S. aureus was the single most common pathogen recovered and one fourth of these cases were methicillin-resistant S. aureus. Given the significant morbidity that may result from inadequate treatment, an antibiotic active against methicillin-resistant S. aureus should be included in the initial broad-spectrum antimicrobial treatment regimen of orbital and subperiosteal abscesses of sinusitis origin until culture results are available.