A 9-year-old boy is brought to the emergency department because of 2 days of worsening redness, swelling, and pain in the area of the right eye. The symptoms were preceded by 5 days of nasal congestion and yellowish rhinorrhea. His temperature is 38.9°C (102°F). On physical examination, the right eye demonstrates significant eyelid edema, erythema, and proptosis. On ocular motility testing, the patient reports pain with eye movement and demonstrates restricted abduction and elevation of the right eye. Visual acuity is 20/25 in the right eye and 20/20 in the left. There is no evidence of a relative afferent pupillary defect.
Which of the following is the most appropriate next step in the management of this patient?
The correct answer is:
A) Contrast-enhanced CT scan of the orbits and sinuses
This patient is presenting with orbital cellulitis, a serious infection of the soft tissues posterior to the orbital septum. It most commonly arises as a complication of bacterial rhinosinusitis, specifically ethmoid sinusitis. Key clinical features that distinguish orbital cellulitis from the less severe preseptal cellulitis include proptosis, ophthalmoplegia (restricted eye movement), and pain with eye movement. Fever and leukocytosis are also common. When these red flag signs are present, the most appropriate next step is a contrast-enhanced CT scan of the orbits and sinuses to confirm the diagnosis and rule out complications such as a subperiosteal abscess, orbital abscess, or cavernous sinus thrombosis. Management requires hospital admission for intravenous antibiotics.
Answer choice B: Incision and drainage of the eyelid, is incorrect. This is the treatment for a chalazion or a hordeolum that has failed conservative management. It is not an appropriate initial step for a deep orbital infection and could potentially spread the infection.
Answer choice C: Outpatient course of oral amoxicillin-clavulanate, is incorrect. This regimen is appropriate for preseptal cellulitis, which involves only the skin and soft tissues anterior to the orbital septum. Preseptal cellulitis does not cause proptosis, pain with eye movement, or restricted motility. Orbital cellulitis is a medical emergency requiring inpatient IV antibiotics.
Answer choice D: Topical erythromycin ointment, is incorrect. Topical antibiotics are used for bacterial conjunctivitis. Conjunctivitis presents with discharge and redness but does not cause the deep tissue swelling, proptosis, or ocular motility issues seen in this patient.
Answer choice E: Warm compresses and oral diphenhydramine, is incorrect. This is a treatment for allergic conjunctivitis or a mild insect bite reaction. While both can cause eyelid swelling, they are typically itchy rather than painful and do not present with high fever or restricted eye movements.
Key Learning Point
Orbital cellulitis is a deep-seated infection posterior to the orbital septum, often secondary to sinusitis. It is distinguished from preseptal cellulitis by signs of orbital involvement, including proptosis, ophthalmoplegia, and pain with eye movement. A contrast-enhanced CT scan is the preferred imaging modality to evaluate the extent of the infection and check for abscess formation.
