Description

• An acute, spreading infection of the skin and SC tissue of the area anterior to the orbital septum but the inflammation does not extend into the bony orbit
• Synonym(s): Preseptal cellulitis

ALERT
It is important to distinguish periorbital cellulitis from orbital cellulitis (posterior to the orbital septum; symptoms include restricted extraocular mobility, diplopia, proptosis, and globe displacement vision loss), which is a potentially life-threatening condition.

Epidemiology

• Occurs more commonly in children, with mean age 21 months.
• 3 times more common than orbital cellulitis (1)

Incidence
Increased incidence in the winter months (due to increased number of cases of sinusitis) (1)

Risk Factors

• Contiguous spread from upper respiratory infection
• Sinusitis
• Local skin trauma
• Insect bite
• Puncture wound
• Bacteremia

Genetics
No known genetic predisposition

General Prevention

• Avoid dermatologic trauma.
• Avoid swimming in fresh or salt water with skin abrasion.
• Thanks to routine vaccination, the incidences of Haemophilus influenzaeB and Streptococcus pneumoniae as potential etiologies for periorbital cellulitis have decreased.

Pathophysiology

• An understanding of the anatomy of the eyelid is important in distinguishing preseptal from orbital cellulitis:
  • The orbital septum is a sheet of connective tissue that extends from the orbital bones to the margins of the upper and lower eyelids, and it acts as a barrier to infection deep in the orbital structures.
  • Infection of the tissues superficial to the orbital septum is called periorbital (aka preseptal) cellulitis, whereas infection deep in the orbital septum is termed orbital (aka postseptal) cellulitis.
• Periorbital cellulitis classically arises from a contiguous infection of soft tissues of the face, secondary to:
  • Sinusitis (via lamina papyracea) extension
  • Local trauma
  • Insect or animal bites
  • Foreign bodies
  • Dental abscess extension
  • Hematogenous seeding

Etiology

• Common organisms: (1)
  • Staphylococcus aureus, typically MSSA (although increasing incidence of MRSA)
  • Staphylococcus epidermidis
  • Streptococcus pyogenes
• Atypical organisms:
  • Acinetobacter sp.
  • Nocardia brasiliensis
  • Bacillus anthracis
  • Pseudomonas aeruginosa
  • Neisseria gonorrhoeae
  • Proteus sp.
  • Pasteurella multocida
  • Mycobacterium tuberculosis
  • Trichophyton sp. (ringworm)
• Since the introduction of the Hib vaccine, the incidence of H. influenzae has decreased; however, this organism should be suspected in the unimmunized or partially immunized.