Overview
Definition:
Preseptal cellulitis, also known as periorbital cellulitis, is an infection of the soft tissues anterior to the orbital septum
Orbital cellulitis is a more serious infection involving the tissues posterior to the orbital septum, including the orbital fat and muscles.
Epidemiology:
Orbital cellulitis is more common in children under 10 years old
Preseptal cellulitis can occur at any age but is also frequent in young children
Common causes in children include trauma, insect bites, or spread from adjacent infections like sinusitis.
Clinical Significance:
Accurate differentiation is critical due to the potential for severe vision-threatening complications and even mortality associated with orbital cellulitis
Prompt and appropriate management can prevent long-term sequelae.
Clinical Presentation
Symptoms:
Preseptal: Eyelid swelling, redness, tenderness, warmth
Possible mild conjunctivitis
No vision changes or limitation of extraocular movements
Orbital: Severe eyelid swelling and redness
Pain with eye movement
Proptosis (bulging eye)
Diplopia (double vision)
Decreased vision
Fever and malaise.
Signs:
Preseptal: Erythema and edema of the eyelids
Tenderness to palpation of the eyelids
Normal visual acuity
Full range of extraocular movements
No chemosis or proptosis
Orbital: Significant chemosis (conjunctival edema)
Restricted or painful extraocular movements
Diplopia
Proptosis
Decreased visual acuity
Possible afferent pupillary defect
Systemic signs of infection (fever, lethargy).
Diagnostic Criteria:
No universally defined criteria exist, but diagnosis is primarily clinical, based on the presence of eyelid inflammation for preseptal cellulitis and the involvement of orbital structures (proptosis, ophthalmoplegia, vision loss) for orbital cellulitis
Imaging is crucial for confirmation and differentiation.
Diagnostic Approach
History Taking:
Recent trauma to the face or orbit
Insect bites
Upper respiratory tract infection symptoms (rhinorrhea, cough)
History of sinusitis, otitis media, or dental abscesses
Onset and progression of symptoms
Associated fever, vision changes, or pain with eye movement.
Physical Examination:
Detailed assessment of eyelids for edema, erythema, and tenderness
Assess for any breach in skin integrity
Evaluate visual acuity
Perform pupillary examination for afferent pupillary defects
Assess range of extraocular movements and presence of pain with movement
Check for proptosis using an exophthalmometer if available
Examine conjunctiva for chemosis and any discharge
Funduscopic examination to rule out optic nerve involvement or retinal findings.
Investigations:
Complete Blood Count (CBC) with differential to assess for leukocytosis
Erythrocyte Sedimentation Rate (ESR) and C-reactive protein (CRP) for inflammatory markers
Blood cultures if sepsis is suspected
Imaging: Computed Tomography (CT) scan of the orbits with contrast is the gold standard for differentiating preseptal from orbital cellulitis
It can identify subperiosteal abscesses, orbital abscesses, sinus involvement, and venous sinus thrombosis
Magnetic Resonance Imaging (MRI) may be preferred if central nervous system involvement is suspected or for better soft tissue detail.
Differential Diagnosis:
Preseptal cellulitis: Allergic reactions, insect bites without secondary infection, dacryocystitis, chalazion, stye
Orbital cellulitis: Periorbital edema due to systemic illness (nephrotic syndrome), orbital tumor, orbital pseudotumor, rhabdomyosarcoma, cavernous sinus thrombosis.
Management
Initial Management:
For suspected orbital cellulitis, immediate referral to ophthalmology and likely admission to hospital is required
For preseptal cellulitis, outpatient management may be considered if the child is otherwise well, afebrile, and has no significant comorbidities
Close follow-up is essential for both
Intravenous (IV) access should be established for potential antibiotic administration and fluid resuscitation.
Medical Management:
Antibiotics: Initial broad-spectrum IV antibiotics covering common pathogens (Staphylococcus aureus, Streptococcus pyogenes, Haemophilus influenzae type b - though less common with vaccination)
For preseptal cellulitis: Oral antibiotics like amoxicillin-clavulanate, cefuroxime, or clindamycin
For orbital cellulitis: IV antibiotics such as ceftriaxone or cefotaxime plus clindamycin or vancomycin
Duration of treatment varies based on clinical response, typically 7-10 days for preseptal and longer for orbital
Antipyretics and analgesics for fever and pain.
Surgical Management:
Surgical intervention is indicated for orbital cellulitis in the presence of a significant subperiosteal or orbital abscess, deteriorating vision despite antibiotics, or suspicion of sinus thrombosis
Surgical drainage of abscesses may be performed via an external ethmoidectomy or endoscopic approach
Consultation with ENT is often necessary.
Supportive Care:
Close monitoring of vital signs, visual acuity, pupillary response, and extraocular movements
Nasal decongestants may be used cautiously if sinusitis is a contributing factor
Humidified air may help with comfort
Adequate hydration and nutritional support.
Complications
Early Complications:
Orbital cellulitis complications: Vision loss (due to optic nerve compression, central retinal artery occlusion, or endophthalmitis), orbital abscess, subperiosteal abscess, cavernous sinus thrombosis, meningitis, brain abscess, sepsis, facial nerve palsy.
Late Complications:
Strabismus (eye muscle imbalance), ptosis, scarring of the eyelids, recurrent infections, chronic sinusitis, vision impairment.
Prevention Strategies:
Prompt treatment of underlying infections such as sinusitis, otitis media, and dental infections
Timely and appropriate management of periorbital trauma
Maintaining up-to-date immunization status, especially for H
influenzae type b.
Prognosis
Factors Affecting Prognosis:
Promptness of diagnosis and treatment initiation
Severity of orbital involvement
Presence of complications like abscesses or vision loss
Virulence of the causative organism
Patient's immune status.
Outcomes:
Preseptal cellulitis generally has an excellent prognosis with prompt antibiotic treatment, leading to full recovery
Orbital cellulitis has a more guarded prognosis
while many children recover fully, there is a significant risk of vision loss and other serious complications
Early intervention is key to minimizing long-term sequelae.
Follow Up:
Close follow-up is mandatory for both conditions
For preseptal cellulitis, follow-up within 24-48 hours is typically sufficient
For orbital cellulitis, daily clinical assessment and repeat imaging may be required until improvement is evident
Long-term ophthalmological follow-up may be necessary for patients who experienced vision impairment or strabismus.
Key Points
Exam Focus:
The ability to distinguish clinically between preseptal and orbital cellulitis is paramount
Remember proptosis, ophthalmoplegia, and vision loss are hallmarks of orbital cellulitis and mandate urgent intervention
CT orbit is the investigation of choice for differentiation.
Clinical Pearls:
Always perform a thorough ophthalmological examination, including visual acuity and EOM, even in seemingly mild periorbital swelling
Do not underestimate a small injury or infection that can lead to orbital complications
Systemic antibiotics are the mainstay of treatment
surgical drainage is reserved for abscesses.
Common Mistakes:
Misdiagnosing orbital cellulitis as preseptal cellulitis due to incomplete examination, leading to delayed treatment and increased risk of complications
Failing to obtain appropriate imaging (CT orbit) when orbital cellulitis is suspected
Inadequate antibiotic coverage or duration of treatment.