Preseptal and Orbital Cellulitis

Preseptal cellulitis is usually caused by contiguous spread of infection from local facial or eyelid injuries, insect or animal bites, chalazion Chalazion Chalazia and hordeola (styes) are sudden-onset localized swellings of the eyelid. A chalazion is caused by noninfectious meibomian gland occlusion, whereas a hordeolum usually is caused by infection... read more , or sinusitis Sinusitis Sinusitis is inflammation of the paranasal sinuses due to viral, bacterial, or fungal infections or allergic reactions. Symptoms include nasal obstruction and congestion, purulent rhinorrhea... read more .

Orbital cellulitis is most often caused by extension of infection from adjacent sinuses, especially the ethmoid sinus. Less commonly, orbital cellulitis is caused by direct infection accompanying local trauma (eg, insect or animal bite, penetrating eyelid injuries) or contiguous spread of infection from the face or teeth or by hematogenous spread.

Pathogens vary by etiology and patient age. Streptococcus pneumoniae is the most frequent pathogen associated with sinus infection, whereas Staphylococcus aureus and Streptococcus pyogenes predominate when infection arises from local trauma. Haemophilus influenzae type b, once a common cause, is now less common because of widespread vaccination. Fungi are uncommon pathogens, causing orbital cellulitis in patients who have diabetes or in those who are immunosuppressed. Infection in children < 9 years is typically with a single aerobic organism; with increasing age, particularly age > 15 years, infection is more typically polymicrobial with mixed aerobic and anaerobic (Bacteroides, Peptostreptococcus) infections.

Because orbital cellulitis originates from large adjacent foci of fulminant infection (eg, sinusitis) separated by only a thin bone barrier, orbital infection can be extensive and severe. Subperiosteal fluid collections, some quite large, can accumulate; they are called subperiosteal abscesses, but many are sterile initially.

Complications with orbital cellulitis include vision loss (3 to 11%) due to ischemic retinopathy and optic neuropathy caused by increased intraorbital pressure; restricted ocular movements (ophthalmoplegia) caused by soft-tissue inflammation; and intracranial sequelae from central spread of infection, including cavernous sinus thrombosis Cavernous Sinus Thrombosis Cavernous sinus thrombosis is a very rare, typically septic thrombosis of the cavernous sinus, usually caused by nasal furuncles or bacterial sinusitis. Symptoms and signs include pain, proptosis... read more , meningitis, and cerebral abscess.

Symptoms and signs of preseptal cellulitis include tenderness, swelling, warmth, redness or discoloration (violaceous in the case of H. influenzae) of the eyelid, and sometimes fever. Patients may be unable to open their eyes because of eyelid swelling. The swelling and discomfort can make it difficult to examine the eye, but when accomplished, examination shows that visual acuity is not affected, ocular movement is intact, and the globe is not pushed forward (proptosis).

Symptoms and signs of orbital cellulitis include swelling and redness of the eyelid and surrounding soft tissues, conjunctival hyperemia and chemosis, decreased ocular motility, pain with eye movements, decreased visual acuity, and proptosis caused by orbital swelling. Signs of the primary infection are also often present (eg, nasal discharge and bleeding with sinusitis, periodontal pain and swelling with abscess). Fever is usually present. Headache and lethargy should raise suspicion of associated meningitis. Some or all of these findings may be absent early in the course of the infection.

Subperiosteal abscesses, if large enough, can contribute to symptoms of orbital cellulitis such as swelling and redness of the eyelid, decreased ocular motility, proptosis, and decreased visual acuity.

Diagnosis of preseptal cellulitis and orbital cellulitis is primarily clinical. Other disorders to consider include trauma, insect or animal bites without cellulitis, retained foreign bodies, allergic reactions, tumors, and inflammatory orbital pseudotumor.

Eyelid swelling may require the use of lid retractors for evaluation of the globe, and initial signs of complicated infection may be subtle. An ophthalmologist should be consulted when orbital cellulitis is suspected.

Preseptal cellulitis and orbital cellulitis are often distinguishable clinically. Preseptal cellulitis is likely if eye findings are normal except for eyelid swelling. The presence of a local nidus of infection on the skin makes preseptal cellulitis even more likely.

If findings are equivocal, if the examination is difficult (as in young children), or if nasal discharge is present (suggesting sinusitis), CT or MRI should be done to exclude orbital cellulitis, tumor, and pseudotumor. MRI is better than CT if cavernous sinus thrombosis is being considered.

The direction of proptosis may be a clue to the site of infection; eg, extension from the frontal sinus pushes the globe down and out, and extension from the ethmoid sinus pushes the globe laterally and out.

Blood cultures are often done (ideally before beginning antibiotics) in patients with orbital cellulitis, but less than one third are positive. Lumbar puncture Lumbar Puncture (Spinal Tap) Lumbar puncture is used to do the following: Evaluate intracranial pressure and cerebrospinal fluid (CSF) composition (see table ) Therapeutically reduce intracranial pressure (eg, idiopathic... read more is done if meningitis is suspected. Cultures of the paranasal sinus fluid are done if sinusitis is the suspected source. Other laboratory tests are not particularly helpful.