Microbiology of Pediatric Orbital Cellulitis and Trends in Methicillin-Resistant Staphylococcus aureus Cases

We reviewed medical records of children with orbital cellulitis with positive cultures at a tertiary institution from 2005 to 2018 to identify microbiology trends and features associated with methicillin-resistant Staphylococcus aureus (MRSA) cases. Cultures obtained from the orbits (n = 33), sinuses (n = 31), and dural cavities (n = 4) had yields of 66.7%, 61.3%, and 75%, respectively, compared with 17.6% of blood cultures (n = 69). Fifty-five patients had positive culture results. Staphylococcus aureus was the most common pathogen isolated (n = 19), followed by Streptococcus species, most commonly Streptococcus anginosus (n = 8). The most frequently prescribed antibiotic combination regimen was ampicillin-sulbactam followed by amoxicillin-clavulanate. There were 8 cases of MRSA. MRSA was associated with an age of presentation <1 year old (P =.034). Other clinical features were similar between MRSA and non-MRSA cases. In infants and neonates, or those with epidemiologic risk factors, MRSA should also be considered.