A 3-year-old boy was brought to the ED by his parents for evaluation of left periorbital swelling. A few days prior to presentation, the child was seen at an outpatient center where he was diagnosed with preseptal cellulitis and given an oral antibiotic. However, even after receiving three doses of the antibiotic, the periorbital swelling and redness around the child’s eye worsened, prompting this visit to the ED.
Physical examination revealed edema and erythema both above and below the left eye, with associated tenderness to palpation. A contrast-enhanced maxillofacial computed tomography (CT) scan, with special attention to the orbits, was ordered; representative images are shown (Figure 1a-1c).
What is the diagnosis?
The CT images of the orbits demonstrated edema in the superficial left eyelid (white arrows, Figure 2a and 2b) and left deep orbital septum (red arrows, Figure 2a-2c). A peripherally enhancing fluid collection centered in the left nasolacrimal gland was present (red asterisks, Figure 2b and 2c) with mild mass effect on the left globe. Opacification was also noted within the paranasal sinuses (white asterisks, Figure 2a-2c). Together these findings indicated sinusitis with dacryocystitis and orbital cellulitis.
Dacryocystitis is an infection or inflammation of the lacrimal sac, usually developing secondary to blockage of the nasolacrimal duct. Orbital cellulitis is an infection involving the contents of the orbit, including the fat and ocular muscles. Orbital cellulitis should not be confused with preseptal cellulitis, which is an infection involving the eyelid occurring posterior to the orbital septum. While both of these conditions are more common in children than in adults, preseptal cellulitis is much more common than orbital cellulitis.
Preseptal cellulitis is typically due to local trauma, local skin infection, or dacryocystitis.1 Preseptal cellulitis rarely extends into the orbit, though a minority of cases have been reported in patients with concomitant dacryocystitis.2 Orbital cellulitis most commonly results from paranasal sinus disease, particularly of the ethmoid sinus, which is only separated from the orbit by the thin lamina papyracea.3 While both preseptal cellulitis and orbital cellulitis can cause eyelid swelling and erythema, preseptal cellulitis is typically a mild condition. Orbital cellulitis, however, is a serious medical emergency that requires prompt diagnosis and treatment to avoid loss of vision and intracranial complications, such as venous thrombosis and empyema.3
Although the clinical features of orbital cellulitis (eg, proptosis, ophthalmoplegia, pain with ocular movement) can sometimes distinguish it from preseptal cellulitis, imaging studies are helpful to confirm the diagnosis.4 As previously noted, prompt recognition, diagnosis, and treatment of orbital cellulitis are essential to avoid serious complications.
Computed tomography has a high specificity and sensitivity in detecting the extension of infection into the orbit and associated complications such as subperiosteal or intracranial abscess. For patients in whom intravenous (IV) contrast is contraindicated or who wish to avoid ionizing radiation, magnetic resonance imaging is a useful alternate modality, and diffusion-weighted imaging is particularly sensitive in diagnosing abscess.5
Since polymicrobial infection is common in periorbital cellulitis, broad-spectrum IV antibiotics (eg, ampicillin-sulbactam, cefuroxime, ceftriaxone, piperacillin/tazobactam) are usually indicated initially.6 The patient in this case was given IV ceftriaxone and clindamycin and oral amoxicillin/clavulanic acid for 3 days, after which he was discharged home in the care of his parents with instructions to complete a 14-day total course of oral amoxicillin/clavulanic acid as well as a 21-day course of fluticasone for nasal irrigation.