**5. Differential diagnoses**

There are several entities to be considered in the differential diagnosis of preseptal cellulitis: [33]


**•** Conjunctivitis

Findings on examination include pain on eye movement, afferent pupillary defect, limited

Blood cultures should be obtained as they correlate with orbital pathogens far better in childhood cases than do cultures from the nasopharynx or conjunctiva. Samples of conjunc‐ tival discharge, eyelid lesions, and lacrimal sac material should be sent for culture. Blood culture results are positive in less than 10% of cases of preseptal cellulitis, whereas skin cul‐

White blood cell (WBC) counts tend to be elevated and cannot be used to differentiate pre‐ septal cellulitis from orbital cellulitis. Levels of ESR and CRP can help in the differentiation of preseptal and orbital cellulitis. However, it must be kept in mind that all of those high

Lumbar puncture may be considered in affected children but not for routine use in the ab‐

Orbital ultrasonography can help in diagnosing orbital inflammation, although it requires

It is quite difficult to distinguish periorbital (preseptal) and orbital cellulitis based just on clinical findings, especially in children. Many of the clinical signs of orbital cellulitis are dis‐ tinctive, such are proptosis andophthalmoplegia, but the correct diagnosis of orbital celluli‐

There are several entities to be considered in the differential diagnosis of preseptal cellulitis:

tis is best confirmed by CT scan with contrast infusion of the orbit[29, 30, 31, 32].

A computed tomography (CT) scan can delineate the extent of orbital involvement[28].

values of routine laboratory results can be seen in preseptal cellulitis.

Biopsy shows edema and polymorphonuclear leukocytes infiltrating tissue planes.

extraocular motions, and resistance on retropulsion.

experienced observers and specialized equipment.

CT scan findings in preseptal cellulitis include the following: **•** Swelling of the eyelid and adjacent preseptal soft tissues

**•** Orbital pseudotumour (idiopathic orbital inflammation)

**•** Obliteration of the fat planes or details of the preseptal soft tissues

ture results tend to be negative.

116 Common Eye Infections

sence of meningitis signs.

**•** Absence of orbital inflammation

**5. Differential diagnoses**

**•** Rhabdomyosarcoma

**•** Retinoblastoma

**•** Perioculartinea **•** Cellulitis, Orbital

[33]

