The Effect of the COVID-19 Pandemic on Trends of Complicated Sinusitis in Western Australia

Abstract

The possible association between COVID-19 and the development of complicated sinusitis in paediatric populations was noted during the COVID-19 pandemic, but understanding of this disease process is still developing. In Perth, Western Australia, a distinctive state of isolation, vaccination status and thorough screening methodology led to a unique experience of the pandemic. We conducted a retrospective cohort study of 129 patients admitted to Perth Children’s Hospital from May 2018 to September 2024. Disease factors were studied, including clinical severity, procedure, COVID status, length of stay and inflammatory markers. A surge in patients was noted during the COVID-19 pandemic, with at least 16 having a concurrent diagnosis of COVID-19 at the time of admission. The study demonstrates that whilst COVID-19 infection was associated with the development of complicated sinusitis, it was not associated with increased severity of disease or an increased likelihood of requiring surgical management. A unique subset of patients emerged with unusual presentations, possibly representing a new disease process of suppurative dacryoadenitis.

1. Introduction

In the early stages of the Novel Coronavirus Disease 2019 (COVID-19) pandemic, COVID-19 was considered by many as a disease predominantly afflicting the elderly and comorbid, largely sparing children of significant disease with few notable exceptions [1].

The Omicron variant, first noted in South Africa in November 2021 [2], had lower mortality and morbidity amongst adults and was much more transmissible compared to preceding variants [3]. Amongst children, it likely held the same level of morbidity and mortality; however, it infected children in much greater numbers than previous and led to a higher number of paediatric hospitalisations compared to previous variants [1,3]. Presentations also differed from those in adults; paediatric patients were much more likely to experience seizures [3] compared to admitted adult patients with COVID-19 [4].

Acute rhinosinusitis is a commonly associated feature of COVID-19 infections, present in up to 75% of symptomatic presentations [5]. Trends in the rate of complications of rhinosinusitis have been reportedly affected by COVID-19, with some studies reporting higher rates of admission for complicated sinusitis following the pandemic [6,7,8]. Despite this, however, complications of acute rhinosinusitis with concurrent COVID-19 infections are rare, and within the literature, there are only several case reports [9]. At the time of writing, only several cases were in paediatric patients [9,10,11], of which all required surgical intervention.

Perth, Western Australia, had very limited exposure to COVID-19 during the early stages of the pandemic. Being an extremely isolated city in an island nation with tightly controlled borders, strict lockdown measures and relatively little civil disobedience, Perth had experienced a cumulative total of 155 cases in a population of 2.6 million people up to 31 January from the start of the pandemic [12].

The advent of the highly contagious Omicron variant led to changes in the public health management of COVID-19 once case numbers began to increase in 2022. On 14 February, daily cases surged past 100 per day for the first time since the start of the pandemic. Subsequently, the “hard border” of the West Australian government ended on 3 March, and the surge ultimately saw a peak of 16,900 cases per day on 16 May [12]. By the end of July, there had been a reported 1,053,190 cases of COVID-19 infection in Western Australia [12].

Uniquely, this surge affected a mostly vaccinated population who had otherwise been almost completely unexposed to the COVID-19 virus. With two years to prepare for the arrival of the COVID-19 pandemic, the surge created an opportunity to study rarer conditions associated with COVID-19 that may occur in a vaccinated population. Amongst patients admitted to Perth Children’s Hospital, it was noted that there was an increased incidence of suppurative complications of rhinosinusitis. Once the surge had come to an end, the admission data during this period were analysed to assess whether any patterns emerged. The aim of this study was to study the effect of COVID-19 on complicated sinusitis in paediatric patients, with a focus on a population that was widely vaccinated but had not had exposure to COVID-19 previously.

2. Materials and Methods

We performed a retrospective cohort study of patients admitted to Perth Children’s Hospital with a primary diagnosis of acute complicated sinusitis. This was defined as per the Chandler classification of complications of acute rhinosinusitis [13] or by the presence of a secondary suppurative complication of rhinosinusitis such as an intracranial abscess or Pott’s puffy tumour.

Admission data were gathered from 18 May 2018, when Perth Children’s Hospital opened, to September 2024. Relevant variables and outcomes were recorded, including age, gender, type of complication (as per the Chandler classification) [13], C-Reactive Protein (CRP) level at presentation, whether the case required operative management, length of stay (LOS), whether or not there was a recorded COVID-19 diagnosis within the current clinical illness and the time between COVID-19 diagnosis and admission. Vaccination status was not assessed as this was not consistently documented in the medical records. All cases involved patients under 16 years of age. Patients admitted with Pott’s puffy tumour were not considered under the Chandler classification.

A positive diagnosis was defined as either a positive rapid antigen test (RAT) or a positive polymerase chain reaction (PCR) test either during admission or in the preceding 1 week prior to presentation. We then compared variables and outcomes between COVID-19-positive (COVID+ve) and COVID-19-negative (COVID−ve) participants to elicit differences between the respective cohorts.

Statistical analysis was performed using the Excel 2016 Data Analysis Pack, including logistic regression analysis of the studied variables.

3. Results

3.1. Admission Data

There were 129 admissions for complicated sinusitis to Perth Children’s Hospital from May 2018 to September 2024. Following the beginning of the COVID-19 surge in Perth in February 2022, 16 patients were admitted with a concurrent COVID-19 diagnosis (see

Table 1. Characteristics of admitted patients before and after the COVID-19 Surge beginning in WA on 14 February 2022 (Individual breakdown of Post-COVID patients in Italics).

	Pre-COVID	Post-COVID	COVID+ve	COVID−ve	No COVID Test	Overall
Gender	40 m, 20 f	39 m, 30 f	8 m, 8 f	21 m, 17 f	10 m, 5 f	79 m, 50 f
Average Age (years)	9.21	7.68	9	6.71	8.73	8.4
Average LOS (days)	6	6.07	5.81	6.23	5.93	6.04
Average CRP	87.9	112.9	124.2	117.7	88.6	101.3
Number of patients operatively managed	30	35	8	20	7	65
Total	60	69	16	38	15	129

). Eight of these patients were diagnosed with COVID-19 prior to presenting to Perth Children’s Hospital, whilst the remaining patients with COVID-19 were diagnosed on admission.

Following the introduction of COVID-19 restrictions in Western Australia in 2020, there was a slight reduction in admissions for complicated sinusitis until the start of 2022 (see Figure 1). As the Omicron variant was introduced and restrictions were concurrently and slowly relaxed in 2022, the number of admissions began to increase, spiking in the second and third quarters of 2022.

There was no significant difference (p < 0.05) between the COVID+ve, COVID−ve and pre-COVID cohorts with respect to the proportion of patients based on the Chandler classification (see Figure 2). In addition to sinugenic orbital complications, four patients were admitted with Pott’s puffy tumour and five patients were admitted with sinugenic extradural empyema secondary to frontal sinusitis (all managed non-operatively).

3.2. Statistical Analysis

Logistic regression analysis was performed on the variables of COVID-19 diagnosis, CRP and whether surgery was performed. Otherwise, there was no statistically significant difference in any of the studied variables between the COVID+ve and COVID−ve cohorts, the likelihood of surgery or the CRP at presentation. Separate logistic regression analysis investigating the Chandler classification demonstrated a significant relationship (p = 0.0008, <0.05) between worsening Chandler classification of disease (i.e., more advanced disease) and the likelihood of requiring surgery.

Of note, there was no significant difference in the average CRP between the COVID+ve and COVID−ve patients, assuming all patients prior to 2022 were COVID−ve (124.2 vs. 99.5, p = 0.153, >0.05). There was a significant difference between the cohorts prior to the start of the COVID-19 surge in 2022 and thereafter with respect to age (9.21 vs. 7.68, p = 0.017, <0.05) and CRP (87.9 vs. 112.9, p = 0.031, <0.05), however. Further logistic regression analysis between these two cohorts did not suggest a significant correlation between age and CRP (p = 0.322)

Fifteen patients were admitted to the hospital without undergoing a documented COVID-19 test. These patients were excluded from the logistic regression analysis with respect to COVID status. Notwithstanding COVID status, there was no significant difference between this cohort and the remaining cohorts with respect to any variable. CRP was significantly lower between this cohort and those who underwent testing (114.5 vs. 88.5, p = 0.03, <0.05)

3.3. Superficial Temporal Space Infections

Three patients presented with atypical suppurative complications in the context of possible recent COVID-19 infection despite testing COVID−ve at admission. These three patients presented 28, 30 and 36 days post likely COVID-19 infection and demonstrated temporal abscesses that were not contiguous with paranasal sinuses (see Figure 3, Figure 4 and Figure 5). One patient underwent serological testing, demonstrating recent COVID-19 infection, whilst the other two patients had a positive RAT test in the community.

4. Discussion

4.1. Discussion of the Findings

In this retrospective cohort study, 129 cases of complicated sinusitis were admitted to Perth Children’s Hospital between 2018 and 2024, including 16 who had a concurrent COVID-19 diagnosis.

The study observed a notable increase in admissions for complicated sinusitis during the COVID-19 surge of 2022, coinciding with the relaxation of public health measures and the introduction of the Omicron variant. This rise in cases occurred in a largely unexposed but vaccinated population, highlighting the potential indirect effects of COVID-19 on sinusitis presentations. It is well known that COVID-19 is associated with mucosal inflammation, particularly with respect to paediatric presentations of croup [3] and so it is not unexpected that sinonasal inflammation precipitating bacterial sinusitis would be a potential consequence, leading to an increasing number of presentations of complicated sinusitis during the pandemic. This trend has been observed in other large, retrospective cohort studies [7,14].

This study is unique in the literature in that it identifies a large number of patients who were COVID+ve at the time of admission and had a presentation of complicated sinusitis likely precipitated by COVID-19 infection. Sixteen cases were COVID+ve at the time of admission, though this number may have been higher when inconsistent screening and testing limitations are considered (discussed below). This cohort did not demonstrate any indication of increased disease severity, with no significant difference in LOS, CRP, Chandler classification or likelihood of undergoing a procedure.

The lack of significant differences between the COVID+ve and COVID−ve cohorts may be attributable to the low number of presentations; however, other studies have similarly reported that admissions for paediatric complicated sinusitis during the COVID-19 pandemic were not clinically more severe, though they were statistically more numerous once lockdown measures were relaxed [6,7,15]. In keeping with the literature, our study suggests that the presence of COVID-19 may not directly exacerbate the severity of complicated sinusitis or increase the likelihood of surgery.

The temporal association between the surge in COVID-19 cases and the increased number of sinusitis admissions may point to indirect effects of the pandemic, namely the effect of lockdowns on community immunity. Multiple large cohort studies have demonstrated a surge in cases of complicated sinusitis following an absence of such cases during COVID-19 community restrictions, as seen in this study [6,7,8,15]. This phenomenon has been observed in other paediatric presentations involving both bacterial and viral infections, and has been coined “immunity debt” [16,17], and is further supported by the present study. Two mechanisms have been previously suggested [15]; firstly, COVID-19 may have a detrimental impact on an individual’s immune function, further supporting the development of secondary bacterial infections [18]. However, this does not explain the increased number of presentations in patients who did not have COVID-19 and who were unlikely to have had previous exposure, owing to Perth’s isolated status. A second proposed mechanism is that social restrictions may have affected pathogen exposure and subsequent immune development in paediatric populations. Again, Perth presents a unique case study owing to its isolated status. Lockdowns and social restrictions were quickly enacted in Western Australia in March 2020, along with the closure of the state border. When restrictions were lifted in the state in June 2020, there was no dramatic increase seen until the COVID-19 surge in 2022, at which time Western Australia experienced amongst the highest per capita cases seen anywhere in the world throughout the pandemic [19]. Beyond an increased incidence of all cases of viral pathogens, it is unclear from the present study whether there is a true “immunity debt” that precipitated presentations of complicated sinusitis or whether this simply reflects the larger volume of viral pathogens circulating in the community.

4.2. Limitations

One important factor in this study was the limitations of COVID-19 testing, both in terms of practical application and accuracy of testing. During the initial COVID-19 surge, all patients presenting to the emergency department underwent screening with RAT testing. As the observation period progressed and COVID-19 restrictions were gradually relaxed, routine screening was replaced with selective PCR testing in patients with a suspected diagnosis of COVID-19. This is possibly demonstrable within the study, with a progressively smaller proportion of complicated sinusitis admissions concurrently diagnosed with COVID-19 and a higher proportion of patients who did not undergo testing during the later stages of the study period. Conversely, it is also likely that the prevalence of COVID-19 was lower at the end of the study period, which would contribute to a declining number of COVID+ve diagnoses.

RAT accuracy in in vivo settings has been estimated to be 63% amongst all paediatric cases and 39% in asymptomatic cases [20]. Of the cases admitted in 2022 that solely underwent RAT resting, there were several for which we maintain a high degree of suspicion relating to their COVID-19 status. All cases were close contacts of COVID-19+ve family members and became unwell with coryzal symptoms at the appropriate time period but never tested positive for COVID-19 themselves on a RAT test. It is anticipated that if these individuals had undergone a PCR test at the appropriate time, then they may have been positive for COVID-19 and hence the increased number of associated cases.

Another limitation of this study is the absence of genotyping available. It has been demonstrated that the COVID-19 surge of 2022 is predominantly attributable to the Omicron variant [21]. Although it may be assumed that cases within this study can be attributed to Omicron, further characterisation of the Omicron variant is difficult due to the absence of genotyping of individual infections. Within the literature, it has been demonstrated that key differences exist between COVID-19 variants [3], but the differences between variants regarding acute rhinosinusitis and its associated complications have not been studied. Further investigation into this area would be of value.

One final consideration is the limitation of applying the Chandler classification to the study. The Chandler classification is a system for delineating orbital complications of sinusitis and can be used to delineate the severity of disease based on the depth of progression, from periorbital cellulitis superficially to cavernous sinus thrombosis deep. It does not capture non-orbital complications, however, including Pott’s puffy tumour or extradural empyema of the frontal lobes. As such, these conditions were excluded from analysis with respect to severity.

4.3. Superficial Temporal Space Infections

Amongst the COVID-19 positive patients, one unusual cohort emerged that is suggestive of a different pathophysiology. Three patients, all male and aged between 10–14, presented with an abscess of the superficial temporal space in the setting of acute rhinosinusitis. Two had a documented infection with COVID-19 between 30 and 36 days prior to presentation, and the third had IgG-positive serology to COVID-19 with a likely infection period 28 days prior to presentation based on the patient’s history but no positive RAT or PCR test. Interestingly, not all patients demonstrated rhinonasal inflammation or orbital inflammation that was contiguous with superficial temporal space infection. One patient had a medial orbital abscess separate from the temporal space (see Figure 4), and another had superficial temporal disease contralateral to the site of rhinonasal inflammation (see Figure 3). This would make contiguous spread of infection unlikely, although haematological spread could not be excluded.

Aside from COVID-19 infection, there are few obvious explanations for the pathophysiology of this disease process. None of the patients had any obvious precipitating events other than COVID-19 and acute rhinosinusitis. All had good dentition, and there were no skin infections or insect bites.

One possible explanation for the disease process is that of suppurative dacryoadenitis, or infection of the lacrimal gland. In all three patients, inflammation appeared contiguous with the lacrimal fossa. Importantly, COVID-19 is known to cause inflammation of the lacrimal glands, with the presence of angiotensin-converting enzyme (ACE2) present in lacrimal tissue, and is important for the viral transmission of disease [22]. The COVID-19 virus has been detected in lacrimal secretions, further suggesting that the lacrimal glands may be affected by the virus [22]. Furthermore, COVID-19 has been demonstrated both radiologically and histopathologically to produce nonsuppurative dacryoadenitis [23,24,25], with the potential for the development of periorbital or orbital cellulitis as a complication [23]. Suppurative dacryoadenitis with extension to the superficial temporal fossa has not been previously documented in the literature to the knowledge of the authors and could represent a disease process not seen prior to the COVID-19 pandemic. It is possible that this disease process is precipitated by viral infection, leading to obstruction of the lacrimal glands with secondary bacterial infection.

5. Conclusions

Case reports of complicated sinusitis in the setting of COVID-19 infection have been previously documented in the literature. The current study supports the notion that COVID-19 is associated with the development of complicated sinusitis, though it is not associated with increased severity of disease. Additionally, several cases of infection of the superficial temporal space suggest a new disease process due to suppurative dacryoadenitis with contiguous extension, though more studies are needed to determine this relationship.