OVERVIEW

What is epiglottitis?

Epiglottitis, also known as "supraglottitis," refers to inflammation of the epiglottis and nearby supraglottic structures. Patients may experience fever (usually high fever), severe sore throat that worsens when swallowing, difficulty swallowing saliva in severe cases, slurred speech, and even difficulty breathing. Without treatment, epiglottitis can progress to life-threatening airway obstruction.

The pathogens causing epiglottitis primarily originate from the nasopharynx and directly invade the area. The lingual surface of the epiglottis and surrounding tissues contain a rich network of lymphatics and blood vessels, making them prone to infection spread and subsequent inflammatory reactions. Once infection occurs, swelling can rapidly progress to the entire supraglottic larynx, potentially leading to rapid airway obstruction.

Is epiglottitis common?

The incidence of epiglottitis in adults in the United States is approximately 1.6 per 100,000. Adult epiglottitis is often associated with coexisting conditions, including hypertension, diabetes, and immunodeficiency.

What are the types of epiglottitis?

Pathologically, epiglottitis can be classified into three types: acute catarrhal, acute edematous, and acute ulcerative.

SYMPTOMS

What are the common manifestations of epiglottitis?

The clinical features of epiglottitis vary depending on age, severity, and cause.

• Pediatric patients may exhibit respiratory distress, anxiety, and a characteristic "tripod" posture, where they refuse to lie flat and instead sit with their trunk leaning forward, neck hyperextended, and chin protruding. Sudden onset and rapid progression (within hours) of dysphagia, drooling, and respiratory distress (the "3D" symptoms) are hallmarks of acute epiglottitis in children. Affected children experience a choking sensation, difficulty inhaling, and appear anxious, agitated, or irritable. Their speech is muffled, often described as a "hot potato" voice.

• Adults may present with the following symptoms:

  • Most commonly, severe sore throat or odynophagia, worsening with swallowing, to the point of difficulty even swallowing saliva.
  • Fever ≥ 37.5°C, often accompanied by chills, with temperatures typically between 38–39°C, and possibly lethargy or pallor.
  • Muffled speech.
  • Drooling.
  • Stridor or dyspnea, even choking.
  • Hoarseness in a minority of cases.

Symptom progression is slower in adults than in children.

How does epiglottitis develop?

Epiglottitis involves inflammation of the epiglottis and nearby supraglottic structures, facilitating rapid infection spread. Swelling can quickly extend to the entire supraglottic larynx, leading to potentially life-threatening airway obstruction.

What severe complications can epiglottitis cause?

• Airway obstruction: Though uncommon, it can occur unpredictably at any stage of the disease or treatment.
• Epiglottic abscess: May result from concurrent epiglottic infection or secondary infection of an epiglottic mucocele. This complication primarily affects adults, with an incidence as high as 30%.
• Secondary infections: Bacteremia or direct spread may lead to secondary infections such as pneumonia, cervical lymphadenitis, cellulitis, septic arthritis, or rarely, meningitis.
• Necrotizing epiglottitis: A rare complication in immunocompromised patients (e.g., those with HIV infection or hemophagocytic lymphohistiocytosis).
• Death: Mortality rates are <1% in children and ≤3.3% in adults. Nearly all deaths result from acute airway obstruction, with most occurring en route to or shortly after hospital arrival.

CAUSES

What are the common causes of epiglottitis?

The causes of epiglottitis include various bacteria, viruses, mixed viral-bacterial infections, fungi, and non-infectious factors. Non-infectious causes include traumatic factors such as thermal injury, swallowing foreign objects, ingestion of corrosive substances, and secondary infections due to allergic inflammatory reactions.

In rare cases, epiglottitis may also occur as a complication of bone marrow or solid organ transplantation.

Who is commonly affected by epiglottitis?

It is commonly seen in children, as well as individuals with hypertension, diabetes, or immunodeficiency.

Is epiglottitis contagious?

It is generally not contagious.

Is epiglottitis hereditary?

It is not hereditary.

DIAGNOSIS

How is epiglottitis diagnosed?

When diagnosing epiglottitis, doctors primarily rely on the patient's complaint of severe throat pain that worsens with swallowing. Examination of the oropharynx may appear normal, while indirect laryngoscopy reveals a congested and swollen epiglottis.

What tests are needed for suspected epiglottitis?

• Direct (routine) oropharyngeal examination is used for initial evaluation. Most patients show normal oropharyngeal findings, with rarely visible enlarged epiglottis. If this examination cannot visualize the epiglottis or is potentially unsafe, clinicians may opt for lateral neck imaging or laryngoscopy.
• Direct visualization of the epiglottis via laryngoscopy (e.g., electronic nasopharyngolaryngoscopy, indirect or direct examination) may be the gold standard for clinical diagnosis. If direct examination is unsafe or inconclusive, or if laryngoscopy is unsafe or fails, radiological imaging can confirm the diagnosis. Lateral soft tissue neck radiography can diagnose epiglottitis, with adult epiglottis width typically exceeding 8 mm. The epiglottic vallecula airspace disappears, and the aryepiglottic folds thicken, usually exceeding 7 mm in width.
• Laboratory tests: Most epiglottitis patients show elevated white blood cell counts, though this is nonspecific. Blood and epiglottis culture detection rates are discussed later.

Epiglottitis is definitively diagnosed if erythema and edema of the epiglottis are observed during direct laryngoscopy (while securing the airway), fiberoptic nasopharyngolaryngoscopy, or oropharyngeal examination. If direct visualization is impossible, lateral neck radiography showing epiglottic swelling can also confirm the diagnosis.

Radiographic imaging isn't always necessary for diagnosing epiglottitis, especially when signs of impending or complete airway obstruction are present, clinical diagnosis is clear, or the epiglottis can be visualized via oropharyngeal examination using a tongue depressor (if safe and tolerated), flexible transnasal laryngoscopy, or other laryngoscopic methods. However, if radiological imaging poses no risk, it may help confirm a suspected diagnosis.

What conditions can epiglottitis be confused with?

The differential diagnosis of epiglottitis includes other causes of acute upper airway obstruction:

• Laryngotracheobronchitis (croup): Epiglottitis can be distinguished by the absence of a barking cough but presence of anxiety and drooling. Direct visualization shows a normal epiglottis, while lateral neck radiography may reveal inspiratory hypopharyngeal distension, subglottic opacity, and a normal epiglottis.
• Uvulitis: Infectious uvulitis may occur alone or alongside epiglottitis or pharyngitis. Severe uvular swelling in isolated uvulitis can mimic epiglottitis. Examination shows characteristic uvular swelling and erythema.
• Bacterial tracheitis: Bacterial tracheitis may complicate viral laryngotracheitis or occur as a primary bacterial infection. Primary bacterial tracheitis can resemble epiglottitis with acute upper airway obstruction, fever, and toxic appearance. However, radiography may show intraluminal pseudomembranes and irregular tracheal walls with normal epiglottis and supraglottic regions, requiring direct tracheoscopy for diagnosis.
• Peritonsillar or retropharyngeal abscess: Peritonsillar or retropharyngeal cellulitis/abscess or other painful oropharyngeal infections in children can cause drooling and neck extension. These infections typically lack the toxic appearance and anxiety of acute epiglottitis. Lateral neck soft tissue radiography may help confirm or exclude epiglottitis.
• Laryngeal or epiglottic vallecula foreign body: Laryngeal or tracheal foreign bodies can cause complete or partial airway obstruction requiring immediate treatment. Esophageal foreign bodies at the cricoid or tracheal bifurcation may compress the airway, causing partial obstruction. Symptoms may appear suddenly without fever.
• Angioedema (allergic reaction or hereditary): Acute angioedema or anaphylaxis presents suddenly without preceding cold symptoms or fever, featuring lip/tongue swelling, urticaria, dysphagia without hoarseness, and sometimes inspiratory stridor. Patients may have a history of allergies or prior episodes.
• Congenital anomalies and laryngeal papillomatosis: Congenital upper airway anomalies and laryngeal papillomatosis may mimic epiglottitis symptoms. However, these conditions progress slowly and typically don’t cause fever (unless concurrent viral infection exacerbates airway narrowing).
• Diphtheria: Diphtheria can resemble epiglottitis clinically. Symptoms usually develop gradually, with sore throat, malaise, and low-grade fever being most common. A gray, well-defined diphtheritic membrane may be present.
• Other causes of epiglottic enlargement: Other causes (e.g., neck radiation, trauma, or thermal injury) are usually identifiable through history. Laryngeal pyocele, an infectious complication of a laryngeal sac (a rare abnormal laryngeal air sac), may clinically and radiographically resemble epiglottitis.

TREATMENT

Which department should I go to for epiglottitis?

ENT or emergency department

Can epiglottitis heal on its own?

No.

How should epiglottitis be treated?

General principles: Treatment of acute epiglottitis focuses on two key aspects:

• Airway maintenance:
• Patients with suspected epiglottitis should be continuously monitored by clinicians capable of rapid resuscitation in settings equipped to stabilize and mechanically ventilate the airway (e.g., emergency department, operating room, or ICU).
• Humidified supplemental oxygen should be provided as needed.
• For patients with severe upper airway obstruction (including epiglottitis), multidisciplinary management is optimal; securing the airway is critical.
• Appropriate antibiotic therapy:
• Antibiotics may be withheld in rare cases where epiglottic edema is clearly caused by inhalation, chemical, or thermal injury.
• Empirical antibiotic therapy for epiglottitis should target the most likely pathogens for the individual patient. Once culture and susceptibility results are available, therapy should be adjusted to optimally cover the isolated organism.
• Epiglottitis is a life-threatening infection, so empirical treatment should begin before culture results are obtained.
• Corticosteroids: The role of corticosteroids in airway management for epiglottitis is controversial. Their potential benefit lies in reducing airway inflammation and improving patency. Corticosteroids are not used in initial epiglottitis treatment but may aid patients with extubation difficulties after several days of appropriate antibiotics.

Does epiglottitis require hospitalization?

Yes.

DIET & LIFESTYLE

What should patients with epiglottitis pay attention to in their diet?

Patients with epiglottitis should be monitored in the intensive care unit and can only consume soft liquid diets after their condition stabilizes and improves. They should avoid spicy and irritating foods, maintain a balanced diet of meat and vegetables, supplement protein, and abstain from alcohol.

Does epiglottitis require follow-up examinations? How are they conducted?

Patients with epiglottitis should be monitored in the intensive care unit (regardless of whether an artificial airway has been established). It is necessary to examine the supraglottic area daily to evaluate treatment efficacy, observe for complications (e.g., epiglottic abscess), and monitor for delayed airway obstruction (in patients without an artificial airway).

PREVENTION

Can epiglottitis be prevented? How to prevent it?

• Infant epiglottitis can be prevented through Hib vaccination, reducing its occurrence.
• Adults can reduce the risk of epiglottitis by preventing pneumococcal infections through immunization.

How can epiglottitis patients prevent complications?

If patients with acute epiglottitis can quickly achieve airway opening and receive appropriate antibiotic treatment, most cases can recover without residual airway issues or other problems. Therefore, seeking immediate hospital treatment is crucial.