Written by Millie Cosse
Orbital cellulitis is a high-risk and low-prevalence disease characterized by a painful, red eye, usually with eyelid erythema. Red flags include pain with eye movements, photophobia, diplopia, decreased visual acuity, decreased color vision, and proptosis.
I spy with my swollen red eye…
Orbital cellulitis is a vision threatening condition primarily seen in children. Potential causes include ethmoid sinusitis (most common cause), trauma, dacryocystitis, dental infections, ophthalmic surgery, peribulbar anesthesia, and endogenous seeding from bacteremia.
It is critical to distinguish orbital cellulitis from preseptal cellulitis. CT brain and orbits with and without contrast is recommended to evaluate for orbital cellulitis and intracranial extension in patients with decreased or double vision, eye movement limitations (including pain), proptosis, relative afferent pupillary defect, or signs/symptoms of CNS involvement. Imaging findings to be on the lookout for include infiltration of the orbital fat, sinusitis, extraocular muscle enhancement, intracranial involvement, and subperiosteal abscess. If CT is non-diagnostic and clinical suspicion remains high, MRI of the brain and orbits with and without contrast is indicated, especially early in the disease course. Laboratory evaluation may help with diagnosis, but stone-cold normal labs cannot rule out this condition. CRP is more frequently elevated in orbital cellulitis when comparted to preseptal cellulitis (78.6% vs. 50.0%), and blood cultures are rarely positive.
Manage orbital cellulitis with broad spectrum antibiotics (below) and early ophthalmology consultation.
How will this change my practice?
Orbital cellulitis is rare, but it is an absolute “can’t miss” diagnosis. Taking the time to review the subtleties of high-risk and low-prevalence diseases might make a world of difference for one of your patients.
Editor’s note: Sometimes, there is a clear periorbital (preseptal) cause, such as a scratch or insect bite on the lid, with superinfection. However, distinguishing periorbital and orbital cellulitis can be difficult. If in doubt, CT is probably best. ~Clay Smith
High risk and low prevalence diseases: Orbital cellulitis. Am J Emerg Med. 2023 Jun;68:1-9. doi: 10.1016/j.ajem.2023.02.024. Epub 2023 Feb 26.