(Infection)

Overview

• Peri-Orbital Cellulitis → inflammation and infection of the superficial eyelid. Infection occurs from a superficial site of inoculation (eg. insect bite). May lead to orbital cellulitis.
• Orbital Cellulitis → infection within the orbital soft tissues. Far more serious condition and warrants hospital admission. Commonly reflects local spread of an URTI, usually sinusitis. May also be due to orbital injury.
• Twice as common in children (M>F) than adults
• Organisms involved include Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus species, and anaerobes.
• Risk Factors → previous sinus infection (sinusitis), lack of Haemophilus influenzae type b (Hib) vaccination, insect bite on eyelid (peri-orbital)

Making Diagnosis

Clinical Features:

• Peri-Orbital Cellulitis → red, swollen, painful eye of acute onset, eyelid oedema and erythema, insect bite on eyelid

• Orbital Cellulitis → redness and swelling around eye, severe ocular pain, visual disturbance, proptosis, pain with eye movements (opthalmoplegia), eyelid oedema

  <aside> 💡 Orbital Cellulitis Distinguishing Features → visual disturbance + proptosis + pain on eye movements (opthalmoplegia)

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Investigations:

• CT Sinus & Orbits with Contrast → performed in all patients suspected to have orbital cellulitis. Can see inflammation of peri-orbital or orbital tissue hence helps differentiate between the two. Assess for posterior spread of the infection.
• WBC Count → elevated
• Blood Culture & Swab → determine causative organism