P0902 - Thinking Beyond Orbital Cellulitis

Introduction
Orbital cellulitis accounts for approximately 2,500 pediatric hospitalizations annually. Although suspicion for orbital cellulitis is high with presenting symptoms of proptosis, conjunctival swelling, diplopia, fever, and leukocytosis, a broad differential diagnosis should be considered.

Case Description
A previously healthy 8 year-old female presented to the emergency department after her teacher noticed one week of progressive right eye swelling. She endorsed photophobia, painful blurry vision, diplopia, as well as recent rhinorrhea, sore throat, and subjective fevers. She denied eye trauma, headache, dizziness, weakness, or rash. Social history was notable for emigration from Guatemala three years prior and lack of health insurance, though her mother reported she was up to date on vaccinations. On exam, she was afebrile with mild posterior oropharyngeal erythema and right-sided periorbital edema and proptosis. She had normal visual acuity and left eye exam, but demonstrated right eye ptosis, limited abduction, and slow pupillary response. CT orbits with contrast showed right periorbital soft tissue swelling without other intracranial abnormalities. She was initially diagnosed with severe orbital cellulitis and admitted to the pediatric floor for antibiotic treatment.
After 24 hours of intravenous ampicillin-sulbactam, she remained afebrile but continued to experience painful ophthalmoplegia, photophobia, diplopia, and proptosis without improvement in her cranial nerve (CN) III palsy. MRI face/orbit showed inflammation in the right cavernous sinus and surrounding dura, with resultant severe right internal carotid artery (ICA) narrowing, suggestive of Tolosa-Hunt Syndrome (THS).

Discussion
THS is a rare idiopathic diagnosis of exclusion. Most cases occur in adults, with approximately 1 case per million annually in the general population. As of 2016, there have been only 16 reported pediatric cases in the literature with average onset at 11 years of age. In THS, non-specific inflammation of the cavernous sinus and/or superior orbital fissure exerts pressure on surrounding nerves, primarily CN III, IV, superior portions of V, and VI. Periorbital pain may precede ophthalmoplegia by up to 30 days. Rarely, visual acuity can become permanently damaged from optic nerve swelling. Mainstay of treatment is high-dose glucocorticoid therapy, which often alleviates pain within 24-72 hours. Although CN palsies may take up to eight weeks to resolve, most patients fully recover.

Conclusion
The differential diagnosis for painful ophthalmoplegia is vast and includes trauma, aneurysm, neoplasm, sinusitis, orbital cellulitis, sarcoidosis, and migraine. For this patient, literature on THS was reviewed to guide evaluation and exclusion of alternative diagnoses. After two days of high-dose glucocorticoids, our patient’s pain improved with eye movements normalizing by day five of treatment. Follow-up MRI imaging revealed improved right cavernous ICA luminal caliber. She was discharged with a glucocorticoid taper, prophylactic daily aspirin, and close outpatient follow-up.