Epiglottitis

Etiology

Epiglottitis etiologies are primarily infectious; noninfectious etiologies are seen. Noninfectious etiologies can be traumatic, such as thermal injuries, blind-finger sweeps to remove a foreign body from the pharynx, angioneurotic edema, acute leukemia, and hemophagocytic lymphohistiocytosis.[11] Other causes include those associated with smoking crack cocaine or marijuana, throat burns affecting the epiglottis of bottle-fed infants, caustic insults, such as automatic dishwasher detergent ingestion, and foreign body ingestion.[12][13][14][15] Epiglottic swelling may occur in lymphoproliferative diseases. While viruses do not cause epiglottitis, a prior viral infection may allow bacterial superinfection to develop. Viruses that may allow a superinfection include varicella-zoster, herpes simplex, and Epstein-Barr.

The most common cause of epiglottitis is a bacterial pathogen. Over 90% of pediatric epiglottitis cases are caused by H influenza type b. However, non-type b H influenza can also cause epiglottitis in vaccinated children.[16] Other known bacterial causes of pediatric epiglottitis include, but are not limited to:

• Streptococcus pneumoniae
• Groups A and C β-hemolytic streptococci
• Staphylococcus aureus
• Moraxella catarrhalis
• Haemophilus parainfluenzae
• Neisseria meningitidis
• Pseudomonas species
• Candida albicans, especially in immunocompromised individuals
• Klebsiella pneumoniae
• Pasteurella multocida
• Human immunodeficiency virus (implicated as a potential, rare cause in infants) [17]

 Known organisms that can cause acute epiglottitis or supraglottitis in adults include:

• H influenzae (25%)
• H parainfluenza
• S pneumoniae
• Group A streptococci
• Less common bacterial etiologies include mycobacteria, Bacteroides melaninogenicus, Enterobacter cloacae, Escherichia coli, Fusobacterium necrophorum, K pneumoniae, N meningitis, and P multocida)
• Less common viral etiologies include herpes simplex viruses Epstein-Barr virus
• In immunocompromised patients, Candida and Aspergillus
• Community-acquired methicillin-resistant S aureus (rare) [18]

Adult Supraglottitis Risk factors

Risk factors for adult supraglottitis include:

• Middle age; average age of 45 
• Body mass index greater than 25 kg/m²
• Diabetes mellitus
• Male sex; man-to-woman ratio, approximately 3:1
• Black or Hispanic ethnicity
• Epiglottic cyst
• Pneumonia
• Sjögren syndrome [19][20]

Epidemiology

Epiglottitis was once thought to affect young children primarily but is now increasingly observed in adults. In the United States, about 1 case per 100,000 people occurs annually, with a consistent rate among adults. The introduction of the Hib vaccine in 1985 significantly reduced childhood epiglottitis, particularly among 2- to 4-year-olds, in whom it is now a rare occurrence.[21]

The childhood-to-adult case ratio dropped from 2.6:1 in 1980 to 0.4:1 in 1993, though vaccine failures do occur. In countries without widespread Hib vaccination, incidence may vary. Epiglottitis diagnoses have risen despite immunization in the United Kingdom, possibly due to severe airway infections like bacterial tracheitis.[22][23] Additionally, after vaccine implementation, the average age of affected children shifted to those aged between 6 and 12.[24]

Pathophysiology

Airway obstruction and respiratory arrest can result from inflammatory edema, pooling, aspiration of oropharyngeal secretions, and distal mucus plugging. Bacterial penetration of the mucosal barrier leads to bacteremia, which can spread to surrounding tissues, particularly the supraglottis in adults, and cause infections in the meninges, skin, lungs, ears, and other areas. The loosely attached lingual surface of the epiglottis allows for rapid swelling and airway narrowing, especially in the smaller pediatric larynx. In adults, edema may spread more gradually into the entire supraglottis, while the tightly bound vocal cord epithelium generally prevents its spread to the glottis.

Pediatric airways differ markedly from adult airways (see Image. The Muscles of the Larynx). In children, the epiglottis sits more superiorly and anteriorly with a slightly oblique angle to the trachea. Compared to the glottis in adults, the narrowest part of the pediatric airway is the subglottis. Additionally, the infant epiglottis is more pliable due to immature cartilage, explaining the higher prevalence of laryngomalacia in young children. Infections causing edema and increased epiglottic mass are more likely to cause symptoms in children due to the cartilage’s pliancy, creating a ball-valve effect where each breath pulls the swollen epiglottis over the airway. In adults, stiffer cartilage may resist this effect, but infections spreading through the supraglottis can still lead to airway instability.

Infections such as H influenzae can cause significant edema and swelling of the epiglottis and supraglottis, rapidly progressing to airway obstruction in patients of any age. While H influenzae remains the most common pathogen, additional pathogens, including Mycobacterium tuberculosis, must be considered in immunocompromised individuals, though the relative frequencies remain consistent.

History and Physical

Any patient with suspected epiglottitis demands urgent attention. The risk of airway compromise should be considered. Although the incidence in children has decreased since the introduction of the Hib vaccine about 40 years ago, and adults may present initially with minor symptoms, all patients with epiglottitis are vulnerable to rapid onset and progression of their symptoms. Many unexplained sudden deaths in adults could be attributed to undiagnosed and inadequately treated epiglottitis. Sudden decompensation, even after the initiation of antibiotics for sore throat, dysphagia, and fever, may still occur.[25] Many speculate that George Washington may have succumbed to an untreated peritonsillar abscess, which led to supraglottitis and airway compromise.[26] 

In children, prodromal symptoms may be absent, or there may be a sudden-onset fever. Stridor, labored breathing, dysphagia, refusal to eat or drink, hoarseness, sore throat, and anxiety may be presenting clinical features. The classic clinical triad is the 3 Ds: drooling, dysphagia, distress with air hunger—and an expression of panic. Intercostal, subcostal, or suprasternal retractions, neck lymphadenopathy, and tachypnea may be present with stridor. The child may be sitting in the tripod position, and cyanosis portends a poor prognosis. Older children may have tenderness and pain with palpation of the hyoid bone.[27]

Physical examination, any manipulation of the patient for monitoring, lying flat, intravenous line placement, and imaging should be avoided to prevent airway compromise. The diagnosis is clinically based, and the evaluation should be delayed to secure the airway. All medical, nursing, and respiratory therapy students should be warned never to use a tongue blade to examine a child's throat with suspected epiglottitis. 

In adults, risk factors may include:

• Diabetes mellitus
• Ethanol abuse
• Hyposplenia
• Autoimmune disease
• Immunosuppression
• Impaired defenses of mucosa or against encapsulated organisms [20]
• Arytenoid edema with Sars-CoV-2 (only documented in 1 case) [28]

Adults may have preceding upper respiratory tract symptoms, including sore throat, odynophagia, or dysphagia. Many complain of a muffled "hot-potato" voice, difficulty lying flat, and difficulty breathing; often, they present with fever without apparent signs and symptoms. Some will be in the tripod position, sitting up on their hands, tongue out, and head forward, while many complain of pain on gentle palpation over the larynx or hyoid bone [27]. Others will have a mild cough, irritability, tachycardia, and a toxic appearance. Similar to pediatric cases, adults with evidence of airway compromise, such as stridor, and breathing compromise, such as respiratory distress, should undergo airway intervention. Adults who are not in extremis should be managed with close monitoring and cautious evaluation.

Evaluation

As previously stated, pediatric epiglottitis should be diagnosed by clinical suspicion. No physical exam, laryngoscopy, laboratory test, or radiologic image is recommended. Securing the airway is the priority. The classic lateral neck radiograph should never be obtained without definitive airway control, and no child should be left unattended to acquire imaging. A lateral neck radiograph will show swelling of the epiglottis, also called the “thumb sign.” (See Image. Epiglottitis, Lateral X-Ray). The lateral x-ray is not necessary to diagnose, but it can be used to narrow the clinical differential diagnosis. Radiography should only be performed in the most stable, comfortable, and cooperative of patients. Approximately 20% of lateral neck radiographs will fail to accurately diagnose epiglottitis, underscoring the need for timely airway intervention and delay of laryngoscopy or other tests. The one exception that has been reported is obtaining computed tomography (CT) of the neck in early or unusual cases, but this should be done with caution because of the positioning of the patient and possible delay of airway control.[29] 

After the pediatric airway is stable, blood cultures and cultures of the epiglottis may be obtained. Some clinicians perform epiglottic cultures during endotracheal intubation; cultures are positive in 50% to 75% of cases.[30] Postintubation chest x-rays are beneficial to rule out pulmonary edema, and pneumonia is identified in approximately 15% of patients. In rare cases, percutaneous transtracheal ventilation has been advocated as a temporizing method if the child cannot be intubated before a tracheostomy.[31] Ultrasonography may help reveal an “alphabet P sign” in a longitudinal view, but it is mainly used in adult patients.[32] A complete blood count with differential, a blood culture, and an epiglottal culture should only be obtained in patients with a secured endotracheal tube.[33] 

Adult epiglottitis evaluation may differ if urgent airway control is not warranted. Close monitoring and fiberoptic nasopharyngoscopy/laryngoscopy by otolaryngology are preferred, with an anesthesiologist available, quickly replacing the need for lateral neck soft-tissue radiography. If a lateral neck x-ray is performed, the criterion of 7-mm thickness (average standard epiglottic thickness is 3 to 5 mm) provides 100% sensitivity and specificity for acute adult epiglottitis.[34] A chest x-ray is helpful to rule out pneumonia; however, most otolaryngologists prefer neck CT if the patient is stable. Transcutaneous sublingual ultrasound scanning may become more valuable in the future.[35] Blood cultures may be positive in about 25% of H influenza cases. If the airway has been secured, epiglottic cultures are helpful, and some clinicians advocate aspiration of epiglottic abscesses with a spinal needle.[36]

Treatment / Management

Epiglottitis is a medical emergency with 2 key treatment goals: airway management and elimination of the infectious pathogen. Airway stabilization must be prioritized before initiating antibiotics, preferably ceftriaxone or an equivalent. Rapid deterioration may occur with little warning, so patients should be treated cautiously to avoid unnecessary sedation, inhalers, racemic epinephrine, or agitation. Oxygen should be offered gently, without force. Common management errors include:

• Underestimation of the seriousness of the clinical situation
• Lack of adequate monitoring
• Rush to airway control, such as intubation without proper expertise in the absence of anesthesia and otolaryngology specialist backup
• Unnecessary physical examination maneuvers or medical procedures that precipitate respiratory collapse, such as placement of an intravenous or using a tongue depressor to examine the throat

Management of Epiglottitis in the Pediatric Patient

Differentiating epiglottitis and viral laryngotracheobronchitis (croup) may be difficult in pediatric cases. Upper airway obstruction may be due to an acute viral infection, primarily due to parainfluenzavirus 1 or 3.[37] Epiglottitis traditionally has affected children aged between 2 and 7 and may be due to Hib vaccine failure or lack of vaccination. The clinical features of epiglottitis should be distinct from croup and include:

• General malaise or anxiety preceding the presentation
• Stridor
• Dyspnea
• Hoarseness
• Fever
• Odynophagia
• Dysphagia
• Drooling
• Cervical lymphadenopathy

Supplemental blow-by oxygen should be administered while preparing for emergent airway management, which often includes controlled intubation or, in severe cases, needle cricothyroidotomy or tracheostomy. Ideally, emergency airway intervention should occur in the operating room to visualize the airway first with a laryngoscope. If endotracheal intubation is not feasible, a tracheostomy should be performed. After securing the airway, empiric antibiotics, such as cefuroxime, ceftriaxone, or cefotaxime, should be administered to cover common respiratory and oral pathogens. Due to heightened clinical awareness and improved protocols, pediatric death rates following intubation or airway control have dropped to less than 1%, though delays in transport or diagnosis still contribute to fatalities.

After securing the airway, patients should be admitted to the intensive care unit, and culture swabs should be obtained post-intubation. Corticosteroids may reduce edema, shortening intensive care requirements. Antibiotic regimens should be adjusted based on culture and sensitivity results. Extubation can be considered once a leak is demonstrated around the deflated endotracheal tube cuff.[38][39](B2)

All non-intubated patients require admission to the intensive care unit with a tracheostomy tray readily available. Otolaryngologists and anesthesiologists must be alerted in case of an emergency airway situation. Nurses should avoid placing the child supine and minimize unnecessary movements or interventions.

Management of Epiglottitis in the Adult Patient

Managing epiglottitis in adults differs significantly from children, as adults often present with inflammation throughout the supraglottis.[2] Advances in monitoring, technology, and fiberoptic laryngoscopy training have reduced the need for urgent intubation or tracheostomy. Unlike children, adults may tolerate physical examinations, imaging, or more conservative measures without immediate airway compromise. Awake fiberoptic intubation, when performed under proper conditions, has a high success rate in less severe cases but should only be attempted with a cooperative patient by trained otolaryngology and anesthesiology specialists and never in extreme cases where immediate laryngoscopy or tracheostomy may be the only option.[40][41]

Otolaryngologic evaluation in adults is crucial to assess airway status and predict the risk of rapid progression. Many otolaryngologists recommend intensive care observation, antibiotics, and steroids for mild-to-moderate swelling in adults without high-risk factors like diabetes or epiglottic abscess. Inhalation induction, common in pediatric cases, has an unclear role in adults, and a backup tracheostomy plan should always be in place.[42]

Adult mortality from epiglottitis can reach 7% to 10%, which is much higher than in children.[43] Neuromuscular blocking agent use remains controversial, as reduced airway tone may cause complete obstruction.[44][45] Airway management failures in adults often result from:

• Extensive edema, distortion of airway anatomy, supraglottic obstruction, and mucus secretions compromising the mechanics of intubation
  • Video laryngoscopy likely plays a lesser role than direct laryngoscopy.
• Disease progression or overzealous airway manipulation
• Stressful clinical scenarios, including suboptimal equipment, training, or cardiac arrest [46]
• Poor preparation for front-of-neck airway access 
(B3)

No consensus exists on the optimal management of adult epiglottitis due to varying clinical presentations, healthcare settings, expertise, and resources. Pediatric epiglottitis may be more straightforward to manage than adult cases, but successful treatment across all ages requires rapid, accurate diagnosis, proper identification of patients needing immediate airway control, anticipation of deterioration, and preparedness for front-of-neck airway access. While no definitive guide for airway management in this life-threatening condition exists, prompt and skilled intervention is essential to prevent fatal outcomes.[47]

Differential Diagnosis

Because of the availability of the Hib vaccine, acute epiglottitis due to H influenzae is less common, though sporadically increasing due to public misconception regarding vaccination. However, H influenzae remains the single most common pathogen responsible for the condition in adults and children. Thus, most clinicians may have less insight into the disorder. This lack often leads to delays in initiating antibiotic therapy. Acute epiglottitis can result in sudden airway obstruction. If this diagnosis is remotely suspected, sending the patient anywhere without proper monitoring and resuscitative equipment is never wise. Other conditions that mimic the presentation include:

• Acute angioedema
• An airway obstruction 
• Bacterial laryngotracheobronchitis (croup)
• Thermal or caustic injury from liquids or hot air (burns)
• Foreign body aspiration
• Laryngeal diphtheria
• Laryngotracheal bronchopneumonitis
• Peritonsillar abscess
• Retropharyngeal abscess
• Sepsis

Prognosis

When diagnosis and management are prompt and efficient, most patients with epiglottitis have a good prognosis. Even those requiring airway control typically have rapid disease resolution without residual sequelae. Those diagnosed with epiglottic abscess may benefit from aspiration.[48] 

Individuals in close contact with epiglottitis patients found to have H influenza type b isolates should receive rifampin prophylaxis 20 mg/kg, not exceeding 600 mg daily, for 4 days. Adult epiglottitis recurrence is rare and may necessitate immunologic workup. Further, in adults with recurrent peritonsillar or retropharyngeal abscesses, the underlying disease process should be addressed, and tonsillectomy may be required to prevent the recurrence of supraglottitis.

Complications

Complications of epiglottitis include:

• Cervical adenitis
• Cellulitis
• Empyema
• Epiglottic abscess
• Meningitis
• Pneumonia
• Pulmonary edema
• Pneumothorax
• Hypoxemia
• Sepsis
• Septic arthritis
• Septic shock
• Vocal cord granuloma
• Ludwig angina-type submental infection
• Respiratory arrest
• Cardiac arrest
• Death