What is the diagnosis and treatment for a patient with new onset headache, orbital pain, periorbital swelling, low-grade fever, and photophobia?

Orbital Cellulitis: Diagnosis and Urgent Management

Primary Diagnosis

This clinical presentation—new onset headache with orbital pain, periorbital swelling, low-grade fever, and photophobia—most likely represents orbital or periorbital cellulitis, which requires urgent imaging and immediate antibiotic therapy to prevent vision loss and intracranial complications. 1

Critical Differentiation: Preseptal vs. Postseptal Cellulitis

The key clinical distinction determines management urgency:

• Preseptal (periorbital) cellulitis: Infection anterior to the orbital septum, more common in children under 5 years, typically following upper respiratory infection (68%) or eyelid trauma (20%) 2
• Postseptal (orbital) cellulitis: Infection posterior to the orbital septum, more common in children over 5 years and adults, typically associated with sinusitis (79%) 2

Red Flags Indicating Orbital (Postseptal) Cellulitis

Immediately assess for these findings that mandate urgent CT imaging: 1

• Proptosis (eye bulging forward)
• Ophthalmoplegia (restricted or painful extraocular movements) 3, 4
• Decreased visual acuity or visual changes 1
• Relative afferent pupillary defect
• Severe headache with altered mental status 1

Immediate Imaging Protocol

CT orbits with IV contrast is the initial imaging of choice and should not be delayed when any red flags are present. 1 This study:

• Differentiates preseptal from postseptal cellulitis 1
• Identifies orbital or subperiosteal abscesses requiring surgical drainage 5
• Detects sinusitis as the source 2

Upgrade to MRI brain with contrast if: 1

• Severe headache with neurologic symptoms suggesting intracranial extension 1
• Suspected cavernous sinus thrombosis 6
• Suspected meningitis or cerebritis 1
• CT findings are equivocal for soft tissue involvement 6

Antibiotic Management

Initiate IV antibiotics immediately without waiting for imaging if orbital cellulitis is clinically suspected. 2

Empiric Antibiotic Regimen

The most effective regimen based on common pathogens (Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus species): 2

• IV ceftriaxone PLUS clindamycin (mean duration 8.6 days in successful cases) 2
• Alternative: Vancomycin plus ceftriaxone if MRSA prevalence is high in your region

Special Population Considerations

In immunocompromised patients (diabetes, neutropenia, transplant recipients, chemotherapy): 5

• Urgent evaluation for invasive fungal sinusitis (Aspergillus, Mucoraceae) is mandatory due to 50-80% mortality 5
• Look for pale nasal mucosa progressing to ulceration and necrosis on examination 5
• CT may show hyperattenuation in sinuses and bone erosion 5
• Requires systemic antifungal therapy PLUS surgical debridement 5

Critical Pitfalls to Avoid

Do not delay CT imaging when proptosis, visual changes, or ophthalmoplegia are present—this can lead to missed orbital cellulitis requiring urgent surgical intervention. 1

Do not assume infection is the only diagnosis. Orbital pseudotumor (idiopathic orbital inflammatory syndrome) can mimic orbital cellulitis with identical presentation: orbital pain, photophobia, periorbital swelling, restricted extraocular movements, and chemosis. 3 Key differences:

• Orbital pseudotumor: CT shows inflammation of sclera, optic nerve, muscle, and adipose tissue without abscess formation 3
• Treatment: Discontinue antibiotics and initiate tapering corticosteroids with prompt symptom resolution 3
• Biopsy may be necessary to exclude lymphoma or other malignancy 6

Do not overlook intracranial complications. Even with gradual onset and minimal initial signs, orbital cellulitis can progress to intracranial extradural abscess, requiring neurosurgical intervention. 4 Assess ocular movement meticulously—this is the major clinical abnormality indicating orbital disorder. 4

Surgical Intervention Indications

Approximately 6% of patients require surgical drainage despite IV antibiotics: 2

• Subperiosteal or orbital abscess identified on imaging 2
• Clinical deterioration despite 24-48 hours of appropriate antibiotics
• Vision-threatening optic nerve compression 6

Alternative Diagnoses to Consider

If Sinusitis Features Are Absent

Uveitis (anterior or posterior): Presents with eye pain, photophobia, blurred vision, and headache, but typically lacks periorbital swelling and fever. 5 Requires urgent ophthalmology referral and slit-lamp examination. 5

Scleritis: Very painful (versus relatively painless episcleritis), may have visual disturbance and photophobia. 5 Requires ophthalmology evaluation for immunomodulatory therapy. 5

If Systemic Features Predominate

Q fever pneumonia: Consider if patient has livestock exposure or rural residence, presents with severe retroorbital headache with photophobia, fever (median 10 days), and nonproductive cough. 7 Notably lacks upper respiratory signs. 7 Treat with doxycycline. 7

Disposition and Follow-up

• Admit for IV antibiotics if orbital cellulitis is confirmed or cannot be excluded 2
• Ophthalmology consultation within 24 hours for all orbital cellulitis cases 5
• Neurosurgery consultation if intracranial extension is suspected 4
• ENT consultation if surgical drainage of sinuses or orbital abscess is needed 2