Paediatric periorbital and orbital infections: a decade of experience at Christchurch Hospital

Periorbital and orbital infections are serious, potentially life-threatening conditions that predominantly affect children.¹ Historically, before the widespread use of antibiotics, these infections carried a high risk of morbidity and mortality, including permanent visual loss.² The introduction of vaccines against Haemophilus influenzae type B and Streptococcus pneumoniae led to a marked decline in invasive infections.^3,4 Periorbital and orbital infections are anatomically classified as preseptal (anterior to the orbital septum) or postseptal (posterior to the orbital septum).⁵ Some literature uses periorbital cellulitis to describe preseptal disease, and orbital cellulitis for postseptal disease. Others use periorbital infections as a broad term for both. To avoid confusion, this article will use periorbital/preseptal cellulitis for disease anterior to the orbital septum and orbital/postseptal cellulitis for disease posterior to the orbital septum. The distinction between preseptal and postseptal cases is clinically significant, as the two entities differ in pathogenesis, management and prognosis.⁶ Preseptal cellulitis typically arises from local trauma or contiguous spread from surrounding infections, while postseptal cellulitis is more often secondary to sinusitis or infection of adjacent structures such as the lacrimal sac.⁷ Postseptal disease is associated with a higher risk of complications, including visual impairment and intracranial spread. This study aims to characterise the clinical and microbiological features, management and outcomes of paediatric periorbital and orbital infections admitted to Christchurch Hospital over a 10-year period, with particular attention to differences between preseptal and postseptal disease.

Methods

A retrospective review was performed of all patients under 18 years admitted to Christchurch Hospital with a diagnosis of periorbital or orbital cellulitis from 1 January 2013 to 31 December 2022. Cases were identified through International Classification of Diseases (ICD) codes for periorbital cellulitis of the eyelid, cellulitis of the face, acute inflammation of the orbit including abscess, cellulitis, osteomyelitis, periostitis, tenonitis and acute sinusitis (L03.2, H00.0, H05.0, J01.0, J01.1, J01.2, JO1.3, J01.8, J01.9). Theatre records were also searched for “functional endoscopic sinus surgery ± middle meatal antrostomy ± ethmoidectomy”, “drainage subperiosteal abscess orbit” and “drainage intraorbital abscess”. These records were cross-checked against the ICD codes. The records were assessed for the following: ethnicity (prioritised ethnicity recorded as per the Ministry of Health – Manatū Hauora ethnicity data protocols), sex (at birth), age, diagnosis, season, length of admission, duration of symptoms prior to admission, potential source of infection (i.e., trauma to skin, sinus infection, dental infection, upper respiratory tract infection, no cause identified), vaccination status (patients were deemed up to date with vaccinations if they had received all of the vaccinations available [for their age] according to the New Zealand National Immunisation Schedule), clinical findings, white blood cells and C-reactive protein count within 24 hours of presentation, whether any oral or topical antibiotics had been administered prior to hospital, if any local microbial culture was taken during admission (microbial swabs from any source), microbial culture and sensitivity/resistance, radiology (including computed tomography [CT] and/or magnetic resonance imaging [MRI]), type and route of antibiotic, whether steroids had been administered, surgical intervention and follow-up plan. ⁸ Descriptive statistics were used to analyse the results. The commonly used Chandler classification system was used to separate preseptal and postseptal infections into type I (inflammatory oedema), type II (orbital cellulitis), type III (subperiosteal abscess), type IV (orbital abscess) and type V (cavernous sinus thrombosis).⁹

Ethics

This study was out of scope for a Health and Disability Ethics Committee review. It was authorised by Health New Zealand – Te Whatu Ora Canterbury (locality authorisation number RO#23214).

Results

Demographics and clinical presentation

Over the 10-year period, 495 children were admitted with either periorbital or orbital cellulitis: 459 (93%) with preseptal and 36 (7%) with postseptal cellulitis (Figure 1). The male-to-female ratio was higher in both groups (1.4:1 preseptal, 1.8:1 postseptal). Preseptal cellulitis patients were younger (median age 3 years) compared to postseptal cases (median age 9.5 years). Those with postseptal disease had a longer length of admission with a median of 4.5 days (range 2–33 days) compared to preseptal disease with a median of 1 day (range 0–8 days). Ethnic distribution showed that nearly half of preseptal cases were New Zealand European (49%), with Māori and Pacific children comprising 20% and 10% respectively. Among postseptal cases, 61% were NZ European, 17% Māori and 19% Pacific peoples.

View Figure 1, Tables 1–4.

Clinical features and predisposing factors

Tables 1–3 describe the demographics and clinical features of the study participants. The majority of both preseptal and postseptal cases were unilateral (Table 2). Trauma (26%) and oculolacrimal infections (16%) were the most common predisposing factors for preseptal cellulitis. In contrast, sinusitis was the leading risk factor for postseptal disease, present in 83% of cases.

Key clinical features distinguishing postseptal from preseptal cellulitis included proptosis, pain on eye movement, ophthalmoplegia and reduced visual acuity. However, even among postseptal cases, proptosis was present in only 56%. The Chandler classification of all cases is displayed in Table 4.⁹

Laboratory and imaging findings

Children with postseptal cellulitis had higher white cell counts and C-reactive protein at presentation, reflecting more severe infection. Imaging of the orbits was performed in 66 patients considered to be at high risk of postseptal infection. Sixty-three patients received CT imaging and three patients received MRI. Twelve patients underwent both MRI and CT imaging. A sinus X-ray was performed in one case in 2013. Forty-five percent of patients who received imaging did not show any features of postseptal cellulitis.

Microbiology

Microbiological cultures were obtained in 228 cases, predominantly from eye swabs, with additional specimens including superficial swabs, abscess swabs and intraoperative samples. In postseptal cases, Staphylococcus aureus (42%) and Streptococcus milleri group (27%) were the most commonly isolated organisms, with no methicillin-resistant strains (MRSA) identified. In preseptal cellulitis, sampling was most often from superficial swabs. Staphylococcus aureus was the predominant pathogen (45%), including four children with MRSA. Other organisms isolated included Haemophilus influenzae (10%; typing information not available), Group A Streptococcus (9%) and Streptococcus pneumoniae (7%).

Management

All patients received antibiotics. Amoxicillin clavulanate was the most common empiric therapy. Sixty-eight percent of preseptal cases received intravenous antibiotics, compared with 100% of postseptal cases. In those with postseptal disease, 19 patients (53%) were treated conservatively with intravenous antibiotics alone, while 17 patients (47%) required operative management. Surgical interventions included: functional endoscopic sinus surgery (n=14, 58%), external (non-endoscopic) subperiosteal incision and drainage (n=9, 38%) and frontal sinus trephine (n=1, 4%). Three patients required multiple operations. Of the preseptal group, 14 (3%) patients also required incision and drainage, mainly due to abscess formation. There was no apparent association between prior antibiotic use and positive culture yield.

Discussion

This study provides the largest single-centre dataset to date on paediatric periorbital infections in New Zealand. The proportion of postseptal cases (7%) was lower than reported in international series (13–21%), potentially reflecting local admission practices and early intervention.^6,10,11

Sinusitis was a major risk factor for postseptal disease, supporting the need for vigilance in children with acute sinusitis and orbital symptoms. The finding that Māori and Pacific children are disproportionately affected echoes broader patterns of infectious disease inequity in New Zealand.¹² Addressing social determinants of health and improving access to timely care remain priorities.

The COVID-19 pandemic and associated public health measures coincided with a marked reduction in preseptal cellulitis admissions in 2020, likely reflecting decreased transmission of respiratory and oculolacrimal pathogens during lockdown periods.¹³

Microbiological findings were consistent with international literature, with Staphylococcus aureus the predominant organism in both preseptal and postseptal disease.¹⁴ MRSA remained uncommon. The frequent use of amoxicillin clavulanate as empiric therapy may reflect its perceived suitability for coverage of the organisms identified.

The study highlights the importance of thorough clinical assessment, with orbital signs (proptosis, ophthalmoplegia, pain on eye movement, reduced visual acuity) prompting urgent imaging to exclude postseptal involvement. Early surgical intervention was required in nearly half of postseptal cases, underscoring the potential severity of this condition.

Limitations

The retrospective design may have led to misclassification or incomplete data capture, particularly with respect to microbiological data, where incomplete clinical documentation precluded accurate classification of swab sampling sites. Ethnicity data were based on prioritised ethnicity and may not fully reflect the paediatric population. The inability to calculate population-based incidence rates limits the ability to make broader epidemiological inferences.

Conclusions

Paediatric periorbital and orbital infections display distinct differences in terms of risk factors, clinical features and outcomes. Sinusitis is a key risk factor for orbital cellulitis, which is often associated with greater morbidity and need for surgical intervention. Māori and Pacific children are over-represented, highlighting ongoing health inequities.

Clinicians should maintain a high index of suspicion for postseptal disease in children presenting with orbital signs, and prompt imaging is recommended. Empiric antibiotic therapy with amoxicillin clavulanate remains appropriate for most cases.