Orbital cellulitis

Question 1

What is orbital cellulitis?

Answer 1

An infection affecting the fat and muscles posterior to the orbital septum, within the orbit but not involving the globe.

Question 2

What is the usual cause of orbital cellulitis?

Answer 2

A spreading upper respiratory tract infection from the sinuses.

Question 3

Is orbital cellulitis a medical emergency?

Answer 3

Yes, it requires hospital admission and urgent senior review.

Question 4

What is periorbital (preseptal) cellulitis?

Answer 4

A less serious superficial infection anterior to the orbital septum.

Question 5

What can cause periorbital cellulitis?

Answer 5

Superficial tissue injury (chalazion, insect bite, etc.).

Question 6

Can periorbital cellulitis progress to orbital cellulitis?

Answer 6

Yes, it can progress.

Question 7

What are the risk factors for orbital cellulitis?

Answer 7

• Childhood
• Mean age of hospitalization 7-12 years
• Previous sinus infection
• Lack of Haemophilus influenzae type b (Hib) vaccination
• Recent eyelid infection/insect bite on eyelid
• Ear or facial infection

Question 8

What are common presentations of orbital cellulitis?

Answer 8

• Redness and swelling around the eye
• Severe ocular pain
• Visual disturbance
• Proptosis
• Ophthalmoplegia/pain with eye movements
• Eyelid oedema and ptosis
• Drowsiness +/- Nausea/vomiting in meningeal involvement (Rare)

Question 9

What symptoms indicate orbital cellulitis over preseptal cellulitis?

Answer 9

Reduced visual acuity, proptosis, ophthalmoplegia/pain with eye movements.

Question 10

What investigations are used for orbital cellulitis?

Answer 10

• Full blood count - WBC elevated, raised inflammatory markers
• Clinical examination - Decreased vision, afferent pupillary defect, proptosis, dysmotility, oedema, erythema
• CT with contrast - Inflammation of the orbital tissues, sinusitis
• Blood culture and microbiological swab

Question 11

What are the most common bacterial causes of orbital cellulitis?

Answer 11

• Streptococcus
• Staphylococcus aureus
• Haemophilus influenzae B

Question 12

What is the management for orbital cellulitis?

Answer 12

Admission to hospital for IV antibiotics.