Shifting patterns of acute epiglottitis: a review of 41 cases in the vaccination era

Summary

Úvod: Akutní epiglotitida (AE) je rychle progredující, potenciálně život ohrožující zánět epiglotis. Dříve typicky dětské onemocnění způsobené Haemophilus influenzae typu b se po zavedení plošné vakcinace objevuje častěji u dospělých. Onemocnění vzniká náhle a může vyžadovat urgentní zajištění dýchacích cest. Cílem této studie bylo popsat klinické charakteristiky pacientů, zhodnotit výskyt komplikací a identifikovat možné rizikové faktory. Materiál a metodika: Retrospektivní monocentrická studie zahrnuje 41 pacientů hospitalizovaných s AE v období od března 2018 do září 2023. Analyzován byl věk, pohlaví, měsíc diagnózy, mikrobiologický nález, antibiotická terapie a přítomnosti komplikací (absces epiglotis, nutnost zajištění dýchacích cest a jeho trvání). Výsledky: Soubor tvořilo 31 mužů a 10 žen, průměrný věk činil 46,7 let. Dospělí převažovali (39 vs. 2 děti). Nejčastěji identifikovanými patogeny byly Streptococcus pyogenes, Haemophilus spp. a anaerobní flóra. Absces epiglotis se vyskytl u 15 pacientů (36,6 %), avšak věk (p = 0,60) ani pohlaví (p = 0,27) nebyly statisticky významnými rizikovými faktory. Intubace byla nutná u 6 pacientů (14,6 %). Vyšší věk i přítomnost abscesu vykázali nevýznamnný trend k vyššímu riziku (p = 0,13; resp. 0,17). Závěr: AE se v dnešní době častěji vyskytuje u dospělých a je spojena s širším spektrem bakteriálních původců. Zajištění dýchacích cest je nezbytné pouze u menšiny pacientů, avšak predikce komplikací zůstává obtížná.

Keywords:

akutní epiglotitida – absces epiglottis – zajištění dýchacích cest – Hib vakcína

Introduction

Acute epiglottitis (AE) is a potentially life-threatening inflammatory disease of the epiglottis and surrounding soft tissues. It can rapidly lead to upper airway obstruction and asphyxia, with fatal outcomes if the airway is not secured in time [1].

Historically, AE was predominantly a pediatric infection caused by Haemophilus influenzae type b. The introduction of universal childhood vaccination in developed countries (since 2001 in the Czech Republic) led to a dramatic decline in incidence among children. The current incidence is 1–4 cases per 100,000, with a marked predominance in adults [2–4]. A greater diversity of bacterial pathogens has also been observed, including Streptococcus pyogenes, Staphylococcus aureus, gram-negative flora, anaerobes, and others [5].

The disease typically presents with the rapid onset of characteristic symptoms, such as sore throat, hypersalivation, dysphagia, odynophagia, and fever. In advanced stages, inspiratory stridor and the characteristic tripod position –⁠ adopted to maximize airway patency –⁠ may be observed [6, 7]. Diagnosis is primarily clinical, based on patient history and presentation. The inflamed epiglottis can be directly visualized, and in some cases, an epiglottic abscess may be evident (Fig. 1). In cases of diagnostic uncertainty or when a broader differential diagnosis is considered (e. g., deep neck infection), contrast-enhanced CT of the head and neck may be helpful [8].

Treatment includes administration of broad-spectrum intravenous antibiotics, securing the airway when necessary (via orotracheal intubation or tracheostomy), drainage of the epiglottic abscess if present, and supportive care including antiedematous therapy [9].

Study aim

This study aimed to describe the clinical characteristics of patients with epiglottitis and to assess the occurrence of complications. A secondary objective was to identify potential risk factors, particularly for the development of epiglottic abscess and the need for airway management.

 

Methods

This retrospective, analytical, single--center study included 45 patients admitted with a diagnosis of acute epiglottitis (ICD-10 code J05.1) who were hospitalized at the ENT department between March 2018 and September 2023. Clinical records were used to collect data on the final diagnosis, age, sex, month of diagnosis, results of microbiological cultures (epiglottitis, abscess), administered antibiotic therapy, and the presence of complications (epiglottic abscess, need for airway management, and its duration).

Four patients were excluded from the analysis after additional examinations confirmed alternative pathologies inconsistent with epiglottitis: one case of parapharyngeal abscess, one of allergic edema, and two of infratonsillar abscesses. The final study cohort thus comprised 41 patients. All data were anonymized before analysis.

Statistical analysis was performed using Python (pandas, scipy, statsmodels, seaborn libraries). Basic descriptive statistics (mean, median, frequencies, percentages) were used to describe the cohort. Comparisons were made using t-tests for continuous variables and Fisher’s exact test for categorical variables. Seasonal variability was evaluated using the chi-squared test. Deviations from expected proportions were assessed using a binomial test. Risk factors were analyzed using univariate and multivariate logistic regression.

Statistical significance was set at an alpha level (a) of 0.05.

 

Results

The study cohort included 41 patients, of whom 31 were male (75.6%) and 10 female (24.4%). The mean patient age was 46.7 years, with a median of 48 years (range 1–83 years). Adults predominated significantly over children (39 vs. 2, both children were female). The male predominance in the cohort was statistically significant (P = 0.0015), while the age difference between sexes was not (P = 0.09). The composition of the cohort is shown in Graph 1.

Microbiological cultures were performed for all patients. In 19 cases (46.3%), at least one pathogen was identified, most commonly Streptococcus pyogenes (N = 6), Haemophilus spp. (N = 4), and anaerobic flora (N = 4). Cultures were negative in 22 cases. A negative culture result was not significantly associated with age (P = 0.63), sex (P = 0.73), or month of occurrence (P = 0.62). An overview of identified pathogens is shown in Graph 2.

Intravenous antibiotic therapy was administered to all patients, with combination regimens used where clinically indicated. The most frequently administered antibiotic was amoxicillin-clavulanate (36 patients), followed by third-generation cephalosporins (N = 5), crystalline penicillin, and metronidazole (each N = 3).

The seasonal distribution of epiglottitis cases over the year is shown in Graph 3. No statistically significant seasonal variation was observed (P = 0.28).

An analysis of complications revealed the presence of an epiglottic abscess in 15 cases (36.6%). Age and sex were not statistically significant risk factors for abscess occurrence (P = 0.60 and P = 0.27, respectively). Due to the small number of cases, the association between abscess and specific pathogens could not be statistically assessed.

Intubation was required in 6 patients (14.6%) with a mean duration of 3.2 days. Data showed a mild trend toward more frequent intubation in older patients, but this did not reach statistical significance (P = 0.13). An analysis of sex and microbiological findings as potential risk factors for intubation was not feasible due to the small sample size. Therefore, a multivariate logistic model including age and sex was used, in which neither factor proved to be a significant risk factor (P = 0.40 for age; P = 0.82 for sex). Intubation was more common in patients with an abscess (odds ratio [OR] = 4.36), although this difference did not reach statistical significance (P = 0.168).

Tracheostomy was performed in only one patient, lasting 11 days; risk factors for this could not be meaningfully assessed.

A summary of complications is provided in Tab. 1.

Discussion

The results of this retrospective study confirm that AE has shifted towards the adult population, with a predominance of male patients. The mean age of patients in our cohort was 46.7 years, and only two cases involved children. The statistically significant male predominance (P = 0.0015) aligns with recent findings reporting increased incidence among middle-aged and older men [6, 10, 11]. These trends reflect the well-documented age shift in AE following widespread Haemophilus influenzae type b (Hib) vaccination, which led to a dramatic decline in pediatric cases [3, 12]. Adults now represent the dominant population affected by this disease.

A broader range of causative organisms has also emerged. Microbiological cultures in our cohort identified a pathogen in 46.3% of cases. The spectrum was wide, most commonly Streptococcus pyogenes, Haemophilus spp., and anaerobic flora. This microbial diversity is consistent with other reports [13–15]. The proportion of negative cultures may be related to prior antibiotic therapy or challenges in obtaining valid samples. Similar rates of negative findings have been reported by other studies [16, 17].

In most cases in our cohort, empirical antibiotic treatment consisted of amoxicillin-clavulanate. Although this broad-spectrum antibiotic is widely used and some studies suggest its use has no impact on morbidity [18, 19], more recent guidelines tend to recommend third-generation cephalosporins, often in combination with anti-staphylococcal agents or metronidazole, due to the diverse range of pathogens seen in adult AE [9, 20–22]. The pathogens identified in our cohort reinforce the rationale for this therapeutic approach.

Although no deaths were recorded and the complication rate was within expected limits based on existing literature, our findings suggest that our current treatment protocols should be reassessed in light of evolving pathogen profiles and updated therapeutic guidelines

Regarding seasonal variation, the available literature remains inconclusive. While some studies report increased incidence during colder months, others do not confirm such variation [1, 6, 23]. Our data did not demonstrate any statistically significant association between seasonality and AE diagnosis, likely due to the limited sample size.

An epiglottic abscess was present in 36.6% of cases, underlining the importance of initial endoscopic examination and continued follow-up. This frequency is consistent with values reported elsewhere, though considerable interstudy variability exists [24–26]. No significant associations were found between abscess formation and patient age or sex, consistent with findings by Sideris et al. [2]. Although we initially aimed to analyze the correlation between abscess occurrence and specific pathogens, the low number of cases per group did not allow for this. However, prior studies have commonly identified Streptococcus spp. and polymicrobial infections as primary culprits [25, 27].

Orotracheal intubation was necessary in 14.6% of patients, with a mean duration of 3.2 days. This aligns closely with rates reported in a recent meta-analysis by Booth et al. [28], though wider variability (10–35%) has been noted in other studies [29, 30]. In our cohort, multivariate analysis showed that neither age nor sex significantly predicted the need for intubation (age P = 0.40; sex P = 0.82). However, univariate analysis revealed a non-significant trend toward more frequent intubation in older patients (P = 0.13), consistent with findings by Pineau et al. [30]. In contrast, Suzuki et al. reported older age and male sex as significant risk factors [11]. The observed trend toward more frequent intubation in patients with abscesses is consistent with risk factor analyses by Sideris et al. [2]. Diabetes mellitus is highlighted in multiple studies as a well-established risk factor [2, 29, 31].

Although airway management in experienced hands is usually straightforward, intubation in patients with epiglottitis may present a unique challenge due to distorted anatomy, edema, and limited visibility. Consequently, the procedure should be approached with caution and ideally performed under controlled conditions by an experienced anesthesiologist and/or ENT surgeon [32].

Tracheostomy was performed in only one case and could not be statistically evaluated. The low rate of tracheostomy aligns with other Western studies, though higher rates have been noted in parts of Asia [1, 11, 29, 33]. In pediatric populations, tracheostomy has become rare due to the decreased incidence of AE [34]. A Finnish study identified tracheostomy as a less economically burdensome alternative, albeit associated with a higher risk of long-term complications [35]. Taken together, our findings and those of previous studies confirm that predicting the need for airway interventions remains clinically challenging, with few consistently reliable risk factors identified.

This study has several limitations, including its single-center design, small sample size, and lack of data on subjective symptoms. Nevertheless, it offers valuable insight into the current epidemiology and complications of AE in a tertiary care setting. Importantly, as AE in children has become increasingly rare, a new generation of pediatricians may lack firsthand experience with the condition. In light of continued global migration, a resurgence of unvaccinated pediatric cases cannot be ruled out. A future multicenter study with a larger cohort and systematic tracking of potential risk factors would be beneficial to refine diagnostic and treatment strategies.

 

Conclusion

Acute epiglottitis is currently a rare disease among vaccinated children, but it has become more common in adults, where it may present with a rapid and potentially life-threatening course due to the risk of airway obstruction. Since the introduction of vaccination, the spectrum of causative pathogens has shifted, necessitating careful selection of empirical antibiotic therapy and potential revision of established treatment protocols. Although complications are not uncommon, predicting them remains challenging, and no reliable risk factors have been clearly defined. Airway intervention is required in only a minority of cases; nevertheless, close monitoring of airway status is essential. Prompt diagnosis is critical for the effective and safe management of this condition.

Abbrevations

AE       acute epiglottitis

ICD      International classification of diseases

CT       computed tomography

 

Conflict of interest statement

The author of this paper declares that he has no conflict of interest in relation to the topic, development, and publication of this paper and that the development and publication of this paper was not supported by any pharmaceutical company. This declaration also applies to all co-authors.

 

Funding

This work was supported by the Cooperatio Program, research area SURG.

Supported by the Ministry of Health, Czech Republic –⁠ conceptual development of research organization (University Hospital in Pilsen (FNPl), 00669806).