Preseptal cellulitis secondary to Proteus species: a case report and review

Preseptal cellulitis is a serious ocular condition that--if left untreated--has the potential to cross the septal barrier, spread to the posterior orbit, and may result in fatal complications. Because it is difficult to determine the pathogen responsible for any cellulitis without aspirating a culture sample, treatment is usually instituted by an assumption of the most common causative organisms, Staphylococcus or Streptococcus.

A 42-year-old black woman manifested signs and symptoms consistent with right preseptal cellulitis. Throughout treatment, visual acuity remained 20/20 for both eyes, extraocular muscles were unrestricted without pain, and anterior globe structures were clear. The patient was started on a regimen of 250-mg oral dicloxacillin four times a day. When no response was seen at 36 hours, the patient was changed to 500-mg oral ciprofloxacin every 12 hours. She responded to the 500-mg ciprofloxacin and recovered with no sequelae. An abscess, which had formed during the cellulitis, self expressed and this material was cultured. The cultures identified the responsible organism as Proteus species, an unexpected pathogen in a well-groomed patient.

This case demonstrates the need to consider alternate pathogens when treating preseptal cellulitis, change medications accordingly, and consider alternate treatments as needed.