MyPACS.net: Radiology Teaching Files > Case 5546515

previously visited LEFT PRE-SEPTAL CELLULITIS AND POST SEPTAL SUBPERIOSTEAL ABSCESS
Contributed by: Dr Phillip Silberberg, Children's Hospital Omaha, Radiologist, Omaha Childrens, Creighton University and UNMC, Nebraska, USA.
Patient: 13 year old
History: 13 year old with L orbital swelling and pain.
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Fig. 1: Left retroseptal periorbital and subperiosteal abscess. Preseptal orbital cellulitis.

Fig. 2: Left preseptal orbital cellulitis. Extraconal left periorbital, retroseptal, and subperiosteal abscess.

Fig. 3: Left ethmoid sinusitis

Fig. 4: Proptosis. Normal enhancement of the superior opthalmic vein. No venous thrombosis which can be seen as a complication.

Fig. 5: Left subperiosteal periorbital abscess. This causes mass effect on the globe and the superior oblique muscle. Note left maxillary and ethmoid sinusitis.
Findings: Fig. 1:   Left retroseptal periorbital and subperiosteal abscess. Preseptal orbital cellulitis.

Fig. 2:   Left preseptal orbital cellulitis. Extraconal left periorbital, retroseptal, and subperiosteal abscess.

Fig. 3:   Left ethmoid sinusitis

Fig. 4:   Proptosis. Normal enhancement of the superior opthalmic vein. No venous thrombosis which can be seen as a complication.

Fig. 5:   Left subperiosteal periorbital abscess. This causes mass effect on the globe and the superior oblique muscle. Note left maxillary and ethmoid sinusitis.
Diagnosis: Left preseptal cellulitis and post-septal subperiosteal abscess.

Secondary to sinusitis (L ethmoid and maxillary sinusitis).
Discussion:

Introduction / Overview:

 

Periorbital inflammation and infection is classified by location and severity, and is most often occurs secondarily to an underlying sinusitis.  The orbital septum is a major landmark and consists of a thin membrane originating from the orbital periosteum and inserting into the anterior surfaces of the tarsal plates of the eyelids. This orbital septum separates the superficial eyelid from deeper structures, and it forms a barrier that prevents infection in the eyelid from extending into the orbit.   Everything anterior to this is known as preseptal, and conditions posteriorly to it are postseptal. 

Etiology:

Upper respiratory tract infections commonly precede preseptal cellulitis, with paranasal sinusitis responsible for 75% of cases.  Ethmoid and Maxillary sinusitis is usually to blame in younger patients.  Adolescents and older patients with developed frontal sinuses are more prone to frontal sinusitis with subperiosteal abscess and a greater tendency towards intracranial extension. 

The most common organisms are Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus species, and anaerobes.  This reflects the organisms that commonly cause upper respiratory tract infections as well as external eyelid infections. Blood and skin culture results tend to be negative.

Pathophysiology:

Preseptal infections may spread posterior to the septum and progress to form subperiosteal and orbital abscesses. Spread of infection occurs via direct extension as well as hematogenously via the venous plexus surrounding the orbit.  Infection in the orbit can spread posteriorly and cause cavernous sinus thrombosis or meningitis.  Subperiosteal abscesses  (SPA) develop when purulent material spreads in between the orbital bones and the perorbital area.  Most commonly this is due to extension of infection from the ethmoid sinus into the muscle cone.  This leads to a rapid increase in orbital pressure with distortion of surrounding structures (orbital muscles, optic nerve, etc).  Being a relatively avascular region, this usually necessitates surgical correction.


Patient Presentation:

 

Preseptal cellulitis is primarily a pediatric disease with roughly 80% of patients less than 10 years old and most patients younger than 5 years. Those with preseptal cellulitis tend to be younger than patients with orbital cellulitis. Most patients will experience symptoms of mild to moderate temperature elevation and many also have pain, conjunctivitis, epiphora, or blurred vision.  Patients can also have periorbital erythema and/or edema, sometimes so advanced that they cannot voluntarily open their eye. 

 

Diagnostic Evaluation:

 

A complete ocular exam is necessarily, with careful screening for systemic illness. 


Radiographic findings are of paramount importance, mainly whether infection is preseptal or postseptal:

CT is the imaging test usually done.  A preseptal cellulitis will show up as an increased density with swelling of surrounding tissues and obliteration of the adjacent fat planes.  An infection from an underlying sinusitis may show a subperiosteal abscess (SPA) appearing as an area of high density directly adjacent to the lamina papyracea.  CT scan is the test of choice to identify such development. 

MRI is useful for assessing extension of the infection and early inflammatory changes in the orbit.  A cellulitis will appear as hypo-intense on T1 and hyperintense on T2 images. 

Ultrasound can be an effective tool, especially in pediatric patients, even though it is not commonly used.  In children with periorbital swelling and erythema it can give reliable differentiation between pre and postseptal infection and easily detects subperiosteal abscesses.  
 

Treatment:

 

MEDICAL TREATMENT:  Preseptal cellulitis confined anteriorly to the soft tissues can usually be treated with antibiotics, as the causes are usually alleric reactions or local skin infections.  Postseptal infections generally need admission to the hospital with IV antibiotics, as 85% are bacterial infections spreading from the sinuses.  This allows for close surveillance.

 

SURGICAL TREATMENT:  Surgical correction is often required for severe sinusitis leading to subperiosteal abscess and postseptal cellulitis.

 

Prognosis:


Morbidity occurs from spread of pathogens to the orbit, which can threaten vision and result in CNS spread. Untreated orbital cellulitis can lead to development of an orbital abscess.  Systemic spread may lead to meningitis and sepsis. Other complications include arterial occlution, osteomyelitis, and cerebral abscess.  Spread posteriorly can lead to cavernous sinus thrombosis, which may lead to cerebrovascular infarct or death.
References:

References:
1. Emedicine.com - Orbit, Infection
2. Mair MH, Geley T, Judmaier W, Gabner I.  Using Orbital Sonography to Diagnose and Monitor Treatment of Acute Swelling of the eyelids in Pediatric Patients. AJR: 2002; 179:1529-1534.
3. Radiology Secrets, 2nd Edition
4. Townbin R, Han B, Kaufman R, Burke M. Postseptal Cellulitis: CT in Diagnosis and Management. Radiology: 1986; 158:735-737.
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Contributed by:

Andrea Lundeen, Medical Student, Creighton University, Omaha, NE
Brandi Reeve, Medical Student, University of Nebraska Medical Center, Omaha, NE
Dr. Phillip Silberberg, Omaha Children’s Hospital,  Omaha, NE

Comments:
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Additional Details:

Case Number: 5546515Last Updated: 05-01-2007
Anatomy: Face and Neck   Pathology: Infection
Access Level: Readable by all users
Keywords: left pre-septal cellulitis and post septal subperiosteal abscess, ophthalmic vien, orbital

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