Laryngeal abscesses are exceedingly rare, accounting for less than 1% of cases of head and neck abscesses (0.4% in our series). Although the epiglottis is the most common site, they can occur in any area of the larynx (Table 2).

The typical clinical presentation includes sore throat (100%) and voice changes (100%), often progressing rapidly to odynophagia and, in some cases, dyspnea and inspiratory stridor (7 out of 13 in our series). Associated febrile conditions are not uncommon. Endoscopic examination is crucial for accurate diagnosis, with findings such as edema, erythema, glottic stenosis, and even vocal cord hypomotility frequently observed in adults [1]. Although our study did not include pediatric cases, suspicion of a laryngeal abscess in children warrants caution to avoid manipulation outside of controlled environments like an intensive care unit or an operating room due to the risk of acute laryngeal closure.

Risk factors for laryngeal abscess development are similar to those for other head and neck abscesses, including poorly controlled diabetes or immunosuppressive treatments, present in just under a third of our patients. However, they can also occur spontaneously without identifiable causes [13]. Various factors such as external trauma [14], iatrogenic causes, foreign bodies, or tumors can contribute to laryngeal abscess formation [2, 15, 16]. Table 3 summarizes the most frequent causes of laryngeal abscesses described in the literature. Our series identified a foreign body, superinfection of a laryngeal cyst, laryngocele, and, notably, epiglottitis as causal factors.

Historically, laryngeal abscesses were primarily caused by systemic diseases such as typhoid fever, tuberculosis, syphilis, or measles, but such cases are now rare [1, 3]. Secondary laryngeal abscesses due to common microorganisms seen in other head and neck abscesses, particularly adult epiglottitis, are more prevalent. Unusual microorganisms implicated in recent laryngeal abscess cases include Mycobacterium tuberculosis [19], Actinomyces odontolyticus [20] and Nocardia farcinia [21], and. In our sample, the microorganisms most commonly associated with laryngeal abscesses were consistent with the predominant underlying pathology, particularly epiglottitis, with Streptococcus species being the most frequently identified pathogens. However, the bacterial diversity observed was highly variable.

Epiglottitis, once prevalent in children in industrialized countries before vaccination against Haemophilus influenzae (HI), remains a significant cause of laryngeal abscesses in adults, accounting for 61% in our series. Previous studies have reported epiglottitis complications leading to abscess formation in 12–19% of adult cases (Fig. 1) [9]. More than 60% of our patients with epiglottitis presented respiratory difficulty, with tracheostomy required in 2 cases and cricothyroidotomy in another, highlighting the potential for life-threatening complications with inadequate management. While abscess drainage typically necessitates general anesthesia and a transoral approach using various instruments, some studies have reported successful drainage using flexible endoscopy under local anesthesia [22].

A large epiglottic abscessed collection (black arrow) with irregular contours that collapses the airway

Laryngopyoceles are laryngeal abscesses resulting from superinfection of a pre-existing laryngocele, characterized by pathological dilation of the laryngeal ventricular saccule, forming air-filled masses in the false vocal cord or neck (Figs. 2 and 3) [10]. These abscesses often present as acute laryngeal obstruction, requiring urgent interventions such as tracheostomy [10]. Treatment typically involves transoral endoscopic marsupialization for internal laryngoceles, while external/mixed laryngoceles may require more radical surgery following resolution of the infectious process [10].

An internal laryngopyocele

Laryngopyocele with external extension

Laryngeal cysts develop due to obstruction of mucinous gland drainage ducts, resulting in glandular secretion retention. While usually asymptomatic or presenting with mild symptoms, laryngeal cysts can undergo acute growth due to superinfection, potentially leading to airway obstruction and abscess formation.

Cricoid/retrocricoid abscesses are a particularly rare form of laryngeal abscesses, typically arising from mucosal injury leading to vascular damage and perichondritis. The formation of abscesses in this area is often triggered by factors such as foreign body impaction, external trauma, prolonged intubation, radiotherapy, or the placement of a nasogastric tube. While some cases may occur spontaneously, they are more commonly observed in immunosuppressed patients [8, 14].

Cricoid/retrocricoid abscesses are typically associated with unilateral or bilateral vocal cord paralysis due to compromised cricoarytenoid joint function [14]. Although our experience did not show any sequelae, these types of abscesses carry a high risk of morbidity due to the potential for late laryngeal stenosis [23]. Abscesses affecting the cricoarytenoid joint have also been reported in patients with conditions like rheumatoid arthritis, often presenting with vocal cord paralysis and edema upon laryngeal examination [11]. Some of these cases have been successfully managed with endoscopic drainage procedures [11].

Other types of laryngeal abscesses described in the literature, such as thyroid cartilage abscesses, involve inflammation of the laryngeal cartilaginous skeleton, known as perichondritis. This condition can lead to the formation of secondary abscesses between the inner and outer layers of the perichondrium. Typically, patients with thyroid cartilage abscesses present with symptoms such as dysphonia (hoarseness) and dyspnea (difficulty breathing) [5, 6].

The causal factors for thyroid cartilage abscesses are similar to those involved in cricoid cartilage abscesses and may also include spontaneous occurrences. Additionally, these abscesses may develop in the context of immunosuppressive conditions such as poorly controlled diabetes [5, 6].

In patients without an imminent risk of airway obstruction, the use of imaging tests plays a crucial role in decision-making and pre-surgical diagnosis. These tests help in identifying the exact location of the abscess and delineating the extent of the collection, aiding in treatment planning.

Among the various imaging modalities, computed tomography (CT) offers the highest diagnostic yield in the emergency department setting. Laryngeal abscesses typically appear on CT scans as an outer ring of hyperenhancement surrounding an inner image of hypoattenuation (Fig. 4). This characteristic imaging pattern helps in distinguishing abscesses from surrounding tissues.

Large intralaryngeal abscess partially obstructing the airway

In our series, presurgical contrast-enhanced CT scans were performed in 9 out of the 13 patients. This imaging approach allowed for accurate localization and characterization of the abscesses, facilitating surgical planning. However, in cases where the severity of the condition posed an immediate threat to the airway, interventions to stabilize the airway took precedence over imaging studies.

Management of laryngeal abscesses requires prompt intervention and collaboration among a multidisciplinary team skilled in managing difficult airways. While small abscesses may respond well to antibiotic and corticosteroid treatment alone (Fig. 5) [16], larger abscesses typically require pus drainage, often performed under general anesthesia. Intubation with an endoscope or video laryngoscope may be necessary (Fig. 6), sometimes with the patient awake. Severe cases with airway obstruction may require a tracheostomy, as was necessary in five of our patients; in one case, a cricothyroidotomy was performed. Although all cases in our study were drained via a transoral route under general anesthesia, local anesthesia techniques using an endoscope have been described for the drainage of epiglottic abscesses [22].

Intralaryngeal abscess localized in the left ventricular band (Black arrow)

Videolaryngoscopy showing an internal laryngocele

Cultures should be obtained to guide antibiotic therapy adjustments. Initial treatment usually involves broad-spectrum intravenous antibiotics such as amoxicillin/clavulanic acid or third-generation cephalosporins, pending culture results. Systemic corticosteroids are commonly administered to alleviate laryngeal obstruction, although the scientific evidence supporting their efficacy is limited [24].

Fortunately, there were no fatalities in our series; however, two patients experienced serious systemic complications. While deaths due to laryngeal obstruction or severe neurological complications have been reported in the literature, our study did not observe such outcomes [25].