Orbital and pre-septal cellulitis

Question 1

What is the most common cause(s) of orbital cellulitis?

Answer 1

Secondary infection from acute bacterial sinusitis

Pathogens:

• Streptococcus pneumoniae
• Staphylococcus aureus
• Haemophilus influenza

Question 2

What are the clinical features of orbital cellulitis?

Answer 2

• Redness and swelling around the eye
• Severe ocular pain
• Visual disturbance
• Proptosis
• Ophthalmoplegia/pain with eye movements
• Eyelid oedema and ptosis
• Drowsiness ± N+V in meningeal involvement (rare)

Question 3

How can you differentiate orbital from preseptal cellulitis?

Answer 3

Features of orbital cellulitis NOT found in preseptal cellulitis:

• Reduced visual acuity
• Proptosis
• Ophthalmoplegia/pain with eye movements

Question 4

What is Chandler’s classification?

Answer 4

Anatomically categorises orbital complications of acute rhinosinusitis

• Group 1 = pre-septal cellulitis
• Group 2 = orbital cellulitis
• Group 3 = subperiosteal abscess
• Group 4 = Intraorbital abscess
• Group 5 = Cavernous sinus thrombosis

Question 5

What empirical abx should be prescribed in orbital cellulitis?

Answer 5

IV 3rd generation cephalosporins (ceftriaxone or cefotaxime)

Metronidazole can also be used

Question 6

What is the preferred imaging modality for orbital cellulitis?

Answer 6

CT orbit scan

Question 7

What antibiotic is typically prescribed for preseptal cellulitis?

Answer 7

Co-amoxiclav or clindamycin (penicillin-allergic)

Question 8

What are the potential complications of orbital cellulitis?

Answer 8

• Subperiosteal or orbital abscess
• Blindness due to involvement of the optic nerve
• Brain abscess
• Rare complications: cavernous sinus thrombosis, central retinal artery occlusion