Findings of preseptal cellulitis
Proptosis: None
Eye movement: Normal (no pain on movement)
Visual acuity: Normal
RAPD: Negative
CT: Only preseptal soft tissue swelling
Preseptal Cellulitis
Key Points at a Glance
Section titled “Key Points at a Glance”1. What is Preseptal Cellulitis?
Section titled “1. What is Preseptal Cellulitis?”Preseptal cellulitis is an acute infectious inflammation of the eyelids and periorbital soft tissues anterior to the orbital septum. The orbital septum is a fibrous membrane that extends from the tarsal plates to the orbital rim, acting as a barrier that physically prevents the spread of infection into the orbit.
It corresponds to Chandler grade I (1970) in the severity classification of orbital infections, and is classified as Group 1 (preseptal or periorbital inflammation) in the Chan classification. Infection of the soft tissues posterior to the orbital septum is orbital cellulitis (Group 2 or higher), which is clearly distinguished from this condition.
Compared to orbital cellulitis, it is more common and generally milder. Sinusitis (especially ethmoid sinusitis), eyelid trauma, insect bites, and facial skin infections are the main triggers, and it is a disease that commonly occurs in children. In adults, it may also develop after dental infections or trauma.
Q
How do you differentiate preseptal cellulitis from orbital cellulitis?
A
Preseptal cellulitis does not involve proptosis, ophthalmoplegia, or vision loss. If any of these findings appear, progression to orbital cellulitis (Chandler grade II or higher) should be suspected, and CT imaging should be performed for evaluation. Checking eye movements, RAPD testing, and visual acuity measurement are essential examination items for differentiation.
2. Main Symptoms and Clinical Findings
Section titled “2. Main Symptoms and Clinical Findings”Subjective Symptoms
Section titled “Subjective Symptoms”- Redness, swelling, and warmth of the eyelid: These are the most characteristic symptoms and often appear and worsen rapidly. Severe swelling may make it difficult to open the eye.
- Pain: Patients often complain of pain around the orbit. Pain with eye movement is usually absent.
- Fever: Occurs as a systemic inflammatory response. High fever may indicate moderate to severe disease.
Clinical Findings Important for Differentiation from Orbital Cellulitis
Section titled “Clinical Findings Important for Differentiation from Orbital Cellulitis”In preseptal cellulitis, the following findings are “absent,” which helps differentiate it from orbital cellulitis.
| Finding | Preseptal Cellulitis | Orbital Cellulitis |
|---|---|---|
| Proptosis | Absent | Present |
| Ophthalmoplegia | Absent | Present |
| Eye pain (pain on eye movement) | None (usually) | Present |
| Decreased visual acuity | None | May be present |
| RAPD (relative afferent pupillary defect) | Negative | May be positive |
| CT findings | Only preseptal soft tissue swelling | Intraorbital inflammation/abscess |
Haddad EL, Tarabichi M. Diagnosing and treating preseptal cellulitis in pediatric patients after a minor trauma. Cureus. 2024;16(12):e74211. Figure 2. DOI: 10.7759/cureus.74211. License: CC BY 4.0.
Preseptal cellulitis in a child with severe redness and swelling closing the entire right eyelid and purulent discharge from the suture line (before starting intravenous antibiotics). No proptosis or deviation from the contralateral eye. Corresponds to the differential findings of eyelid cellulitis without proptosis or motility disturbance discussed in the section “Main symptoms and clinical findings”.
Findings of orbital cellulitis
Proptosis: Present
Eye movement: Impaired (pain on movement)
Visual acuity: May be decreased
RAPD: May be positive
CT: Intraorbital inflammation or abscess formation
Warning signs indicating progression to orbital cellulitis
Section titled “Warning signs indicating progression to orbital cellulitis”If any of the following findings newly appear during treatment, immediately suspect progression to orbital cellulitis (Group 2 or higher) and repeat CT imaging. 1)
- Appearance of proptosis
- Appearance of eye movement impairment
- Decreased visual acuity
- No improvement within 24 to 48 hours after starting treatment
- Worsening headache or altered consciousness (suggesting intracranial complications)
3. Causes and Risk Factors
Section titled “3. Causes and Risk Factors”Routes of Infection
Section titled “Routes of Infection”Preseptal cellulitis can develop through several routes.
- Spread from sinusitis (ethmoid sinusitis): The most common route in children. The ethmoid sinus is adjacent to the medial orbital wall (lamina papyracea), and valveless veins run between the sinuses and the orbit. This allows infection to easily spread to the periorbital soft tissues. 2) In children, the sinuses are immature and the bone is thin, making infection spread more easily.
- Eyelid or facial trauma: Abrasions, insect bites, animal bites, etc., where the skin barrier is broken, allowing normal flora to enter. The eyelid skin is thin, and even minor injuries can become a starting point for infection.
- Spread from facial skin infections: Direct extension from impetigo, skin cellulitis, etc.
- Secondary infection of hordeolum or chalazion: Eyelid inflammation may progress to preseptal soft tissue infection.
- Odontogenic infection: Dental infection of the upper jaw can ascend and cause preseptal cellulitis (more common in adults).
Causative Organisms
Section titled “Causative Organisms”- Staphylococcus aureus: The most common causative organism, often involved in infections from skin trauma or insect bites.
- Streptococcus (Group A and B): May spread from pharyngeal or skin infections.
- Haemophilus influenzae: Before the Hib vaccine became widespread, it was a major cause in children, but its incidence has decreased dramatically after vaccination. Unvaccinated children can still develop infection.
- MRSA (Methicillin-resistant Staphylococcus aureus): Depending on local and facility drug susceptibility, empirical treatment may need to consider this organism.
- Anaerobic bacteria: May be involved in cases with dental infection or sinusitis.
Risk Factors
Section titled “Risk Factors”- Children (especially under 10 years old)
- History or complication of sinusitis (especially ethmoid sinusitis)
- Eyelid or facial trauma (insect bites, abrasions, animal bites)
- Recurrent upper respiratory tract infections
- Immunocompromised state (HIV infection, steroid use, malignancy, etc.)
- Unvaccinated (Hib vaccine)
Q
Can an insect bite cause preseptal cellulitis?
A
Insect bites on the eyelid or face can cause preseptal cellulitis. Bacteria normally present on the skin (Staphylococcus aureus, Streptococcus, etc.) can enter through the bite wound and cause infection. If after an insect bite the eyelid redness and swelling rapidly increase and are accompanied by fever, suspect progression to cellulitis and seek medical attention.
4. Diagnosis and Examination Methods
Section titled “4. Diagnosis and Examination Methods”Clinical Diagnosis
Section titled “Clinical Diagnosis”The diagnosis of preseptal cellulitis is primarily based on clinical findings. The examination systematically checks the following:
- Presence of proptosis (using Hertel exophthalmometer or visual inspection)
- Presence of ocular motility restriction or pain on eye movement
- Visual acuity test (best corrected visual acuity)
- Pupillary response (assessment of RAPD: evaluation of the relative afferent pupillary defect)
- Intraocular pressure measurement
If proptosis, ocular motility restriction, visual loss, or positive RAPD are absent, clinical differentiation from orbital cellulitis is possible.
Imaging Studies
Section titled “Imaging Studies”CT (orbit and paranasal sinuses) is the mainstay of diagnosis. Contrast-enhanced CT is preferred to evaluate the extent of inflammation anterior and posterior to the septum and the presence of sinusitis.
- Findings of preseptal cellulitis: Only soft tissue swelling anterior to the septum. No intraorbital inflammation or abscess formation.
- Findings of progression to orbital cellulitis: Inflammatory infiltration within the orbit, subperiosteal abscess, or orbital abscess formation.
- Sinus findings: Note mucosal thickening or opacification of the sinus cavities (especially the ethmoid sinus). Confirmation of sinusitis directly affects treatment strategy (need for otolaryngology consultation).
In mild cases with low suspicion of sinusitis and a clear trigger such as trauma or insect bite, clinical diagnosis and initiation of antibiotic therapy may be considered, with CT performed if no improvement within 48 hours.
Blood and Culture Tests
Section titled “Blood and Culture Tests”| Test | Purpose |
|---|---|
| Blood tests (CRP, WBC) | Assessment of inflammation severity and monitoring |
| Blood culture | Rule out bacteremia (high fever, severe cases) |
| Nasal and wound culture | Identify causative organism and antibiotic sensitivity (if possible) |
Differential Diagnosis
Section titled “Differential Diagnosis”| Differential diagnosis | Key differentiating features |
|---|---|
| Orbital cellulitis | Proptosis, motility restriction, vision loss → confirm with CT |
| Hordeolum (stye) | Localized eyelid mass, no fever, limited course |
| Allergic eyelid edema | No redness, no fever, rapid resolution, recurrent |
| Orbital tumor | Chronic course, mass on imaging, no response to antibiotics |
| Dacryoadenitis | Localized to lateral upper eyelid, tenderness, often after cold in chronic type |
| Contact dermatitis | History of eye drops or cosmetics use, non-infectious, no fever |
5. Standard Treatment
Section titled “5. Standard Treatment”Stratification of Treatment Strategy
Section titled “Stratification of Treatment Strategy”Treatment for preseptal cellulitis is stratified into outpatient management and inpatient management based on severity.
Criteria for Outpatient Management
General condition: Good, no high fever (below 38°C)
Degree of swelling: Limited to localized eyelid swelling
Age: Older children to adults (children over 1 year old and adults)
Follow-up: Able to return for re-evaluation within 24-48 hours
Other: No immunodeficiency, good medication adherence
Criteria for Hospitalization
General condition: High fever (≥38.5°C) · Poor general condition
Degree of swelling: Extensive swelling · Rapid progression
Age: Infants (especially under 1 year old)
Insufficient improvement: No improvement within 24–48 hours after starting outpatient treatment
Other: Immunocompromised · Difficulty taking oral medication · Presence of complications
Antibiotic Therapy
Section titled “Antibiotic Therapy”Mild cases/Outpatient management (oral antibiotics)
| Drug | Dosage | Indication |
|---|---|---|
| Cefdinir (Cefzon®) 100 mg | 3 times daily orally (Children: 9 mg/kg/day divided into 3 doses) | Mild cases/Outpatient management |
| Amoxicillin/Clavulanate (Augmentin®) 250 mg | 3 times daily orally | Mild cases/Outpatient management (alternative) |
| Clindamycin | Children: 10 mg/kg/dose, 3 times daily, oral | Penicillin allergy cases |
Moderate to severe cases / Inpatient management (intravenous antibiotics)
| Drug | Dosage | Indication |
|---|---|---|
| Ceftriaxone | 50–100 mg/kg/day, IV | Moderate to severe / Inpatient |
| Vancomycin | IV (when considering MRSA, dose adjustment based on weight) | Suspected MRSA / Severe cases |
| Ampicillin/Sulbactam | IV | When anaerobic coverage is needed |
In MRSA-endemic areas or cases unresponsive to outpatient treatment, consider switching to broad-spectrum coverage including vancomycin.
Collaboration with Otolaryngology
Section titled “Collaboration with Otolaryngology”If sinusitis (especially ethmoid sinusitis) is confirmed, otolaryngological intervention is necessary. In adults, otolaryngological treatment for sinusitis is often required. If medical therapy fails, consider functional endoscopic sinus surgery (FESS) in collaboration with an otolaryngologist.
Follow-up (Most Important Point)
Section titled “Follow-up (Most Important Point)”Reassessment within 24 to 48 hours after starting treatment is mandatory. Check the following points:
- Improvement in eyelid swelling and redness
- Appearance of proptosis or ophthalmoplegia (progression to orbital cellulitis)
- Presence of vision loss or relative afferent pupillary defect (RAPD)
- Changes in fever and general condition
If improvement is insufficient or worsening occurs (new onset of proptosis or ophthalmoplegia), suspect progression to orbital cellulitis (Group 2 or higher) and immediately repeat CT and transition to inpatient management. 2)
Q
Can treatment be done without hospitalization?
A
Mild cases with good general condition, mild fever, and localized eyelid swelling can be managed as outpatients with oral antibiotics. However, reassessment within 24 to 48 hours after starting treatment is necessary to confirm improvement. If worsening occurs (proptosis, ophthalmoplegia, or vision loss), switch to inpatient treatment.
Q
Are there any signs to watch for during treatment?
A
The appearance of proptosis, restriction of eye movement (ophthalmoplegia), decreased vision, worsening headache, and altered consciousness are dangerous signs indicating progression to orbital cellulitis or a more severe form. If these occur, immediate re-examination is required, along with repeat CT and urgent evaluation by a specialist.
6. Pathophysiology and Detailed Mechanism of Onset
Section titled “6. Pathophysiology and Detailed Mechanism of Onset”Anatomy and Function of the Orbital Septum
Section titled “Anatomy and Function of the Orbital Septum”The orbital septum is a fibrous membrane that extends from the tarsal plate to the arcus marginalis of the orbital rim, functioning as a barrier at the anterior orbit. This membrane physically prevents the spread of infection into the orbit, making it difficult for preseptal infections to extend into the orbital cavity.
In children, the orbital septum is thin and immature, so they are more prone to progression to orbital cellulitis compared to adults. Additionally, the lamina papyracea, which separates the ethmoid sinus from the orbit, is also thin in children, allowing easy spread of infection from sinusitis to the periorbital area.
Mechanism of Infection Establishment
Section titled “Mechanism of Infection Establishment”- Via trauma or insect bite: Disruption of the skin barrier allows skin commensals (e.g., Staphylococcus aureus, Streptococcus) to invade the eyelid and periorbital soft tissues, causing acute infectious inflammation.
- Spread from sinusitis: Because the ethmoid sinus is adjacent to the medial orbital wall, inflammation and infection from sinusitis can directly spread to the preseptal soft tissues. Hematogenous spread via valveless veins also plays a role. 2)
- Extension from facial skin infection or surrounding cellulitis: Impetigo or facial cellulitis can extend to the periorbital soft tissues.
Mechanism of Progression to Orbital Cellulitis
Section titled “Mechanism of Progression to Orbital Cellulitis”When inflammation extends beyond the orbital septum into the orbit, it progresses to orbital cellulitis (Group 2 or higher). In cases with sinusitis, rapid progression from the ethmoid sinus to subperiosteal abscess (Group 3) via the medial orbital wall may occur. 2)
The progression pathway is stepwise as follows:
- Group 1 (preseptal cellulitis) → Group 2 (orbital cellulitis) → Group 3 (subperiosteal abscess) → Group 4 (orbital abscess) → Group 5 (cavernous sinus thrombosis)
Transition between stages can occur within hours to days, so reassessment within 24 to 48 hours is essential.
7. Latest Research and Future Perspectives
Section titled “7. Latest Research and Future Perspectives”Hospitalization criteria and outpatient protocol for pediatric preseptal cellulitis
Section titled “Hospitalization criteria and outpatient protocol for pediatric preseptal cellulitis”For the decision between outpatient and inpatient management of pediatric preseptal cellulitis, stratification based on age, inflammatory response, and symptom severity is being explored. Establishing quantitative criteria for safe management with oral antibiotics alone is expected to reduce unnecessary hospitalizations while ensuring safety.
Response to MRSA and changes in causative organisms
Section titled “Response to MRSA and changes in causative organisms”In empirical treatment of preseptal cellulitis, antibiotic selection based on regional MRSA prevalence and drug susceptibility is important. Since hospital-acquired MRSA and community-acquired MRSA differ in pathology and susceptibility, empirical treatment selection based on local drug susceptibility surveillance is required.
Establishment of quantitative differential diagnostic criteria using imaging findings
Section titled “Establishment of quantitative differential diagnostic criteria using imaging findings”Research is underway to establish quantitative differential diagnostic criteria (e.g., thickness and extent of soft tissue swelling) for preseptal cellulitis and orbital cellulitis using CT findings. Setting objective thresholds for imaging diagnosis is expected to improve the accuracy of appropriate triage and treatment stratification.
8. References
Section titled “8. References”- Vanga S, Daniel AR, Gould MB, Ramlatchan SR, Ganti L. A Diagnostic Challenge: Periorbital or Orbital Cellulitis? Cureus. 2023;15(11):e48439. PMID: 38074053. PMCID: PMC10702408. doi:10.7759/cureus.48439.
- Colombe MM, Nabuloho EH, Opondjo FM, et al. Acute ethmoiditis complicated by intraorbital abscess, orbital cellulitis, and cerebral empyema in a 14-year-old girl. Clin Case Rep. 2023;11:e6984. PMID: 36852125. PMCID: PMC9957698. doi:10.1002/ccr3.6984.