What is the most appropriate initial step for a patient presenting with nasal purulent discharge, eye pain, periorbital swelling, severe headache, frontal bone tenderness, and restricted Extraocular Movement (EOM)?

Contrast-Enhanced CT Scan is the Most Appropriate Initial Step

This patient requires immediate contrast-enhanced CT imaging of the maxillofacial region, sinuses, and orbits to evaluate for life-threatening complications of acute bacterial rhinosinusitis, specifically orbital and intracranial extension. 1, 2

Clinical Presentation Indicates Complicated Acute Bacterial Rhinosinusitis

This patient presents with classic features of complicated acute bacterial rhinosinusitis with orbital involvement:

• Restricted extraocular movements (EOM) indicates postseptal (intraorbital) involvement, distinguishing this from simple preseptal cellulitis 1
• Periorbital swelling with eye pain suggests orbital cellulitis or subperiosteal abscess 1, 2, 3
• Severe frontal headache with frontal bone tenderness raises concern for intracranial extension including epidural abscess, subdural empyema, or osteomyelitis (Pott's puffy tumor) 1, 2
• Purulent nasal discharge confirms the sinusitis source 1

Why Contrast-Enhanced CT is Essential

The American College of Radiology designates CT maxillofacial with IV contrast as the first-line imaging examination for acute rhinosinusitis with suspected orbital or intracranial complications. 1, 2

Key diagnostic advantages:

• 87% diagnostic accuracy for intracranial complications, with excellent visualization of both bony sinus anatomy and soft-tissue complications 1, 2
• Identifies the extent and type of orbital involvement (preseptal vs. postseptal cellulitis, subperiosteal abscess, orbital abscess) that determines surgical vs. medical management 1, 2
• Detects intracranial complications including epidural abscess, subdural empyema, brain abscess, venous thrombosis, and meningitis 1
• Guides urgent surgical planning when drainage procedures are needed 1, 2

Why Other Options Are Inappropriate

Oral Amoxicillin (Option A) is Dangerous

• Oral antibiotics alone are contraindicated when proptosis, impaired visual acuity, or impaired/painful extraocular mobility is present 1
• This patient requires hospitalization and intravenous antibiotics (such as vancomycin to cover methicillin-resistant S. pneumoniae) 1
• Antibiotic therapy should only be initiated after imaging confirms the diagnosis and extent of complications 2

Reassurance (Option C) is Negligent

• Complicated acute bacterial sinusitis can result in permanent blindness, neurologic sequelae, or death if not treated promptly 1
• The presence of restricted EOM indicates established orbital involvement requiring urgent intervention 1, 3

ENT Referral (Option D) is Premature

• While multidisciplinary consultation with otolaryngology, ophthalmology, and infectious disease is appropriate, this should occur simultaneously with or immediately after imaging, not before 1, 2
• Imaging must be obtained first to guide the surgical and medical management decisions 1, 2

Immediate Management Algorithm

1. Order contrast-enhanced CT of maxillofacial region/sinuses/orbits immediately 2
2. Hospitalize the patient while awaiting imaging 1
3. Initiate broad-spectrum IV antibiotics after imaging (e.g., vancomycin plus ceftriaxone or high-dose amoxicillin-clavulanate IV) 1, 2
4. Obtain urgent consultations with otolaryngology, ophthalmology, and infectious disease while imaging is being performed 1, 2
5. Proceed to surgical drainage if subperiosteal or orbital abscess is identified, or if no improvement occurs within 24-48 hours of IV antibiotics 1

Critical Pitfalls to Avoid

• Do not delay imaging to start antibiotics or arrange consultations—these should occur in parallel 2
• Do not assume preseptal cellulitis based on periorbital swelling alone; restricted EOM definitively indicates postseptal involvement 1, 3
• Do not order non-contrast CT—contrast enhancement is essential for detecting orbital and intracranial complications 1, 2
• Do not discharge with oral antibiotics when any orbital signs are present; this requires inpatient management 1

The answer is B: Contrast-enhanced CT scan.