Description

• Periorbital or preseptal cellulitis is an acute infection characterized by pain, erythema, and edema to the anterior eyelid and surrounding tissue.
• The infection lies superficial to the orbital septum, a thin fascial layer forming the anterior boundary of the orbital compartment.
• In contrast, orbital cellulitis (postseptal disease) is a deep space infection involving the deeper structures of the orbit and requires emergent intervention.

Epidemiology

• Often occurs in young children, commonly <5 years of age but can occur at any age
• Periorbital cellulitis is at least 3 times more common than orbital cellulitis.

Risk Factors

• Predisposing factors that may lead to periorbital cellulitis include local skin trauma (e.g., insect bite, scratch, eczema) and lacrimal/eyelid injury.
• There is a slight increase incidence of orbital cellulitis in winter months.

General Prevention

• Haemophilus influenzae type b vaccine has decreased the incidence of H. influenzae-associated periorbital cellulitis.
• Pneumococcal conjugate vaccine may decrease streptococcal disease.

Pathophysiology

• Often, extension from an external source including trauma (insect bite, recent surgery, foreign body) or adjacent infection (sinusitis, dacryocystitis, hordeola, dental abscess)
• In contrast, orbital cellulitis is often caused by paranasal sinus disease.

Etiology

Variable depending on mechanism

• Most common pathogens are from skin flora including
  • Staphylococcus aureus (increasingly methicillin-resistant)
  • Group A Streptococcus
  • Streptococcus pneumoniae
  • Other streptococci species
• Anaerobic infections can extend from dental source.
• H. influenzae type b was historically the most common pathogen; consider in unimmunized child <5 years of age.

Commonly Associated Conditions

Rarely associated with bacteremia; however, consider this condition in children <3 years of age or in immunocompromised patients.