Periorbital Infections Workup

Updated: Jun 01, 2021
  • Author: Bobak Zonnoor , MD, MMM; Chief Editor: Gil Z Shlamovitz, MD, FACEP  more...
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Approach Considerations

Laboratory studies

The following laboratory studies may be performed in patients with periorbital infection:

  • Periorbital cellulitis - Diagnosis is based primarily on clinical findings. Laboratory or radiologic workup is not required. Thus, a complete blood cell (CBC) count with differential is not routinely necessary, but it may be helpful if bacteremia or sepsis is a concern; blood cultures may also be performed if bacteremia or sepsis is a concern; skin culture has a very low yield. Wound culture of a purulent drainage site may be helpful if a resistant or unusual pathogen is suspected. [43]

  • Dacryoadenitis - A CBC count with differential and blood culture may be performed if bacteremia or sepsis is a concern; serology testing may be indicated if a viral etiology needs to be established.

  • Canaliculitis and dacryocystitis - Culture of expressed material may help to guide therapy

  • Blepharitis - No laboratory studies are indicated routinely

Lumbar puncture

If a patient with periorbital cellulitis is toxic appearing, a lumbar puncture may be indicated to exclude meningeal infection.


Biopsy may be indicated in the following cases:

  • Blepharitis - Biopsy may be indicated in some cases to rule out malignancy

  • Dacryoadenitis - Lacrimal gland biopsy may be indicated in chronic disease

Schirmer test

The Schirmer test is used to assess tear production. Results are nonspecific as to the etiology of dry eyes.


Imaging Studies

Periorbital cellulitis

Contrast-enhanced computed tomography (CT) scanning of the orbits should be performed if there is concern for orbital and subperiosteal involvement and cavernous sinus thrombosis. CT scanning also helps to distinguish sinusitis as a cause.

Indications for CT scanning include the following [61] :

  • Inability to perform a full evaluation of the eye due to edema

  • Proptosis

  • Ophthalmoplegia

  • Decreased visual acuity or color vision

  • Bilateral periorbital edema

  • Inability to exclude postseptal involvement
  • Central nervous system involvement (eg, focal neurological deficits, seizure, altered mental status)
  • Clinical deterioration or no improvement after 24-48 hours following initiation of appropriate treatment

CT scanning will show lid edema but no proptosis or "streaking" of the orbital fat, which lies posterior to the orbital septum.

Patients whose condition fails to improve after 24-36 hours of appropriate antimicrobial therapy should also have CT performed. [61]

In an attempt to better target patients needing emergent CT scanning, Rudloe et al presented a recursive partitioning model for identification of predictors of intraorbital or intracranial abscess, for use in pediatric patients with signs or symptoms of periorbital infection. [62]

Results of the study confirmed that patients with proptosis and/or pain or limitation of extraocular movements are at high risk for intraorbital abscess, though many patients with abscess do not have these predictors. The investigators also concluded, based on multivariate analysis, that the following findings can identify patients at significant risk when the obvious predictors are not present:

  • Peripheral blood neutrophil count over 10,000/μ L

  • No infectious conjunctivitis,

  • Periorbital edema

  • Age older than 3 years

  • Previous antibiotic use

Magnetic resonance imaging (MRI) with MR venography is the study of choice to rule out cavernous sinus thrombosis, although the initial evaluation is often done with CT venography. [63]


20-MHz ultrasonography can be used to detect sulfur granules within the canaliculi. [64]


Jones Dye Test

The Jones dye test is used to assess patency of the lacrimal drainage system. In the first part of the test, a drop of fluorescein is placed in the conjunctival cul-de-sac. After 5 minutes, the nose is examined for the presence of dye. If no dye is present, an obstruction is present and the second part of the test is performed.

In the second part of the test, a cannula is placed into the lacrimal sac, which is then washed with saline. If no fluorescein is noted, the dye is obstructed in the upper (canalicular) portion of the system. If dye is present, then the obstruction is in the lower (sac, duct) portion. [65]


Other Tests

The main role of MRI is the evaluation of intracranial complications such as cerebritis or cavernous sinus thrombosis.