Infections of the orbital and periorbital regions usually present as periorbital swelling and, in most cases, result from complications of acute sinusitis. However, trauma, insect bites, conjunctivitis, dacryocystitis, and blepharitis are alternative causes [1–3]. Staphylococcus, Streptococcus, and H. influenzae account for the majority of infected pathogens [1, 3, 4]. Currently, community-acquired MRSA has become increasingly prevalent. McKinley et al. found that MRSA represented 73% of all pediatric S. aureus orbital infections . Empirical intravenous antibiotic treatment should have coverage against H. influenzae, streptococcal and staphylococcal species. A CT scan is the most useful tool to evaluate the extent of the infection and the location of the accumulated pus [4, 6]. In addition, a CT scan can assess the sinuses and explore the other causative factors.
Controversy exists about the medical or surgical management of orbital abscesses in pediatric patients. Some otolaryngologists advocate medical treatment initially, and surgery is reserved for nonresponders, whereas others suggest immediate surgical drainage whenever the CT scan shows the presence of an orbital abscess. The objectives in the surgery of orbital abscess are to release the pressure on the orbit, drain the abscess, and obtain a specimen for culture [4, 6, 8]. Because successful medical treatment relies on normal visual examination, and inadequate treatment might lead to the loss of vision [4, 6, 8], early surgical intervention is indicated in infantile patients due to the inability to perform a reliable and serial ophthalmologic examination.
The majority of the results from blood cultures are negative in patients with orbital abscess . Therefore, the choice of antibiotics relies on the specimen of pus culture. In our case, the organism of the pus culture was MRSA, which reminds physicians of the increasing prevalence of community-acquired MRSA infection [1, 2, 5]. If a patient's response to empirical antibiotics is inappropriate, and surgical drainage is impeded, we suggest adding antibiotics which are effective against MRSA in order to extend the coverage of medical treatment. Trimethoprim or clindamycin plus a second- or third-generation cephalosporin is a reasonable initial regimen for the coverage of MRSA and pathogens associated with rhinosinusitis [3, 5].
Physicians need to be aware of the clinical presentations and classical CT findings of orbital abscesses. Early surgical drainage of an orbital abscess might be indicated in infantile patients to avoid the complications of visual loss. Due to the emergence of community-acquired MRSA, before obtaining the results from a pus culture, physicians should consider empirical antibiotics that are effective against MRSA.