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 at <5 years of age but can occur at any age
• Periorbital cellulitis is at least 3 times more common than orbital cellulitis.

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.
• Haemophilus influenzae type b was historically the most common pathogen; consider in unimmunized child <5 years of age.
• Less common causes such as Acinetobacter species, Bacillus species, Neisseria gonorrhea, Pasteurella multocida, and Mycobacterium tuberculosis have been reported and are typically linked to specific exposures. Fungal pathogens should be considered in immunocompromised children including those who are on immunosuppressive therapy such as prolonged steroid use.

RISK FACTORS

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

GENERAL PREVENTION

• H. 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.

COMMONLY ASSOCIATED CONDITIONS

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