Chronic use of nasal decongestants, presented with abrupt onset of fever with chills and rigor, diplopia on lateral gaze
# A 19 year old young girl with previous history of repeated pain over medial canthus and chronic use of nasal decongestants, presented with abrupt onset of fever with chills and rigor, diplopia on lateral gaze, moderate proptosis and chemosis. On examination, the optic disc is congested. Most likely diagnosis is: A. Cavernous sinus thrombosis B. Orbital cellulitis C. Acute ethmoid sinusitis D. Orbital apex syndrome The correct answer is: A. Cavernous sinus thrombosis Explanation: The clinical presentation described—abrupt onset of fever with chills, diplopia , proptosis , chemosis , and optic disc congestion —is characteristic of cavernous sinus thrombosis (CST) . This condition is often secondary to infections in the medial canthus (commonly from facial infections or sinusitis), which can spread to the cavernous sinus via valveless facial veins. Key Differentiation: B. Orbital cellulitis : Also presents with proptosis and chemosis but typically lacks systemic signs like severe f...