Allergic fungal sinusitis masquerading as cavernous sinus thrombosis

Allergic fungal sinusitis (AFS), a noninvasive form of fungal sinusitis, is rarely seen in immunocompetent patients. Involvement of sphenoid sinus can result in proptosis and loss of vision. We report AFS masquerading as posterior cavernous sinus syndrome. A 59-year-old African-American man presented with right complete ptosis with ophthalmoplegia. After an initial work-up and imaging studies, patient underwent endonasal sphenoid surgery, which revealed characteristic 'allergic fungal mucin'. Cavernous sinus syndrome is a rare presenting clinical feature of allergic fungal sinusitis. Ophthalmologists should be aware of this rare presentation of relatively common otorhinological disease for timely referral and appropriate management.