Periorbital and orbital cellulitis Flashcards
What is orbital cellulitis?
Orbital cellulitis is an infection affecting the fat and muscles posterior to the orbital septum, within the orbit but not involving the globe. It is usually caused by a spreading upper respiratory tract infection from the sinuses and carries a high mortality rate. Orbital cellulitis is a medical emergency requiring hospital admission and urgent senior review.
What is periorbital (preseptal) cellulitis?
Periorbital (preseptal) cellulitis is a less serious superficial infection anterior to the orbital septum, resulting from a superficial tissue injury (chalazion, insect bite etc…). Periorbital cellulitis can progress to orbital cellulitis.
What are the risk factors for orbital cellulitis?
Risk factors include 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, and ear or facial infection.
What are the common presentations of orbital cellulitis?
Common presentations include redness and swelling around the eye, severe ocular pain, visual disturbance, proptosis, ophthalmoplegia/pain with eye movements, eyelid oedema and ptosis, and drowsiness +/- nausea/vomiting in meningeal involvement (rare).
How can you differentiate orbital cellulitis from preseptal cellulitis?
Reduced visual acuity, proptosis, and ophthalmoplegia/pain with eye movements are NOT consistent with preseptal cellulitis.
What investigations are used for orbital cellulitis?
Investigations include full blood count (WBC elevated, raised inflammatory markers), clinical examination involving complete ophthalmological assessment, CT with contrast (inflammation of the orbital tissues deep to the septum, sinusitis), and blood culture and microbiological swab to determine the organism.
What are the most common bacterial causes of orbital cellulitis?
The most common bacterial causes are Streptococcus, Staphylococcus aureus, and Haemophilus influenzae B.
What is the management for orbital cellulitis?
Management includes admission to hospital for IV antibiotics.
What is preseptal cellulitis?
Preseptal cellulitis, also referred to as periorbital cellulitis, is an infection of the soft tissues anterior to the orbital septum, including the eyelids, skin, and subcutaneous tissue of the face.
How does preseptal cellulitis differ from orbital cellulitis?
Preseptal cellulitis is an infection of the soft tissues anterior to the orbital septum, while orbital cellulitis is an infection of the soft tissues behind the orbital septum and is more serious.
What are common causes of preseptal cellulitis?
Infection usually spreads from nearby sites, commonly from breaks in the skin or local infections such as sinusitis or respiratory tract infections.
Most frequently causative organisms include Staph. aureus, Staph. epidermidis, streptococci, and anaerobic bacteria.
Who is most commonly affected by preseptal cellulitis?
Preseptal cellulitis occurs most commonly in children, with 80% of patients under 10 years old and a median age of presentation of 21 months.
When is preseptal cellulitis more common?
It is more common in the winter due to the increased prevalence of respiratory tract infections.
What are the symptoms of preseptal cellulitis?
The patient presents with a red, swollen, painful eye of acute onset, likely accompanied by fever.
What signs indicate preseptal cellulitis?
Signs include erythema and oedema of the eyelids, partial or complete ptosis, and absence of orbital signs such as pain on movement, restriction of eye movements, proptosis, visual disturbance, chemosis, and RAPD.
What are significant differentials for preseptal cellulitis?
Significant differentials include orbital cellulitis and allergic reactions.
What investigations are done for preseptal cellulitis?
Investigations include blood tests for raised inflammatory markers, swabs of any discharge, and contrast CT of the orbit to differentiate between preseptal and orbital cellulitis.
How is preseptal cellulitis managed?
All cases should be referred to secondary care for assessment. Oral antibiotics, usually co-amoxiclav, are frequently sufficient. Children may require admission for observation.
What are the complications of preseptal cellulitis?
Bacterial infection may spread into the orbit and evolve into orbital cellulitis.
