Makindo Medical Notes

Preorbital (preseptal) cellulitis is a bacterial infection localized to the tissues anterior to the orbital septum. While less severe than orbital cellulitis, it requires prompt recognition and treatment to prevent progression into the orbit and subsequent complications. It is commonly seen in children but can affect individuals of all ages. Usually managed as an outpatient.

Aetiology

• Local trauma: Insect bites, minor lacerations, or abrasions around the eyelid.
• Adjacent infections: Spread from nearby infections, such as hordeolum (stye), dacryocystitis, or sinusitis.
• Hematogenous spread: Rare, resulting from systemic bacterial infections.
• Common pathogens:
  • Staphylococcus aureus (including MRSA).
  • Streptococcus pyogenes.
  • Streptococcus pneumoniae.

Pathophysiology

The infection remains confined to the anterior portion of the eye, without involving the orbital contents. The orbital septum, a fibrous barrier, prevents the spread of infection into the orbit unless compromised.

Clinical Features

• Swollen, erythematous eyelids.
• Warmth and tenderness around the affected area.
• Ptosis (drooping of the eyelid).
• Absence of pain with eye movement, proptosis, or vision changes (key to differentiating from orbital cellulitis).
• Possible fever, but systemic symptoms are usually mild.

Complications

• Progression to orbital cellulitis.
• Rarely, abscess formation or cavernous sinus thrombosis.

Investigations

• Clinical diagnosis: Based on physical examination.
• Imaging:
  • CT scan of the orbit may be required to exclude orbital cellulitis or abscess if severe swelling, systemic symptoms, or poor response to treatment are observed.
• Blood cultures: In severe cases to identify systemic infection.
• Microbiological swabs: From open wounds or discharge to identify causative organisms.

Differential

Feature	Orbital Cellulitis	Preorbital (Preseptal) Cellulitis
Definition	Medical emergency characterized by bacterial infection of tissues posterior to the orbital septum (within the orbit), posing a severe sight- and life-threatening risk.	Localized infection of tissues anterior to the orbital septum; less severe than orbital cellulitis.
Clinical Presentation	Swollen eyelids, fever, chemosis, history of facial laceration, trauma, insect bite, or sinusitis.	Similar to orbital cellulitis but usually confined to the anterior tissues without orbital involvement.
Key Symptoms	Ophthalmoplegia (restricted eye movement). Proptosis (eye bulging). Severe eye pain, especially on movement. Blurred vision or decreased visual acuity. Diplopia (double vision).	Skin erythema, lid oedema, warmth, and tenderness. Ptosis and pyrexia. No proptosis or pain on eye movement. Localised pain and swelling but vision is unaffected.
Common Pathogens	Streptococcus pneumoniae, Haemophilus influenzae type b, staphylococci, or streptococci often linked to trauma or sinusitis.	Same as orbital cellulitis.
Complications	Potential to extend into the skull, causing meningitis, cavernous sinus thrombosis, and blindness.	Extension beyond or into the skull is uncommon.
Imaging	Computed tomography (CT) scan to determine the extent of the infection (preorbital vs. orbital) and exclude complications such as abscess formation.	Same as orbital cellulitis.
Management	Same-day referral to an ophthalmologist. Co-management with ENT specialists. Blood cultures and IV broad-spectrum antibiotics to cover likely pathogens until culture results are available. Requires inpatient care initially.	Same as orbital cellulitis in severe cases. Milder cases may be managed with oral antibiotics and ambulatory care.

Management

• Antibiotics: Prompt treatment of preseptal cellulitis is crucial to prevent complications, although it is typically managed on an outpatient basis unless severe. Mild cases: Oral antibiotics such as amoxicillin-clavulanate or cephalexin. Consider doxycycline or clindamycin for MRSA coverage. Severe cases or high-risk patients: Hospital admission for intravenous antibiotics (e.g., ceftriaxone plus vancomycin).
• Supportive care: Warm compresses to reduce swelling and discomfort. Analgesics and antipyretics for symptom relief.
• Referral: Ophthalmology consultation for patients with uncertain diagnosis, severe swelling, or suspected orbital involvement.

Prognosis

• With timely treatment, preseptal cellulitis typically resolves without complications.
• Delayed or inadequate treatment can lead to progression into orbital cellulitis, which is a medical emergency.

Prevention

• Prompt treatment of minor eyelid injuries and infections.
• Good hygiene to prevent bacterial contamination.
• Timely management of sinusitis and adjacent infections.

References

• American Academy of Ophthalmology
• Royal College of Ophthalmologists