Acute epiglottitis

Notes

Overview

Acute epiglottitis refers to inflammation of the epiglottis and surrounding supraglottic mucosa.

Acute epiglottitis can be a life-threatening condition due to airway obstruction.

Thankfully, acute epiglottitis is now rare in children due to the introduction of the Haemophilus influenzae type B (Hib) vaccination as part of the routine immunisation programme. In adults, the incidence is estimated at 1-4 per 100,000 people.

In children, the median age at presentation has increased to 6-12 years (traditionally affected children 2-5 years old). Children who have not been vaccinated are at particular risk.

Basic anatomy

The epiglottis is a thin layer of elastic cartilage that sits at the base of the tongue.

The epiglottis is a leaf shaped piece of elastic cartilage that protects the airway during swallowing. It contains a layer of stratified squamous epithelium on its anterior surface and superior third of the posterior surface.

Epiglottis anatomy

Aetiology

Haemophilus influenzae type B (Hib) was the classical cause of epiglottitis in children prior vaccination.

Acute epiglottitis may be caused by a number of infectious microorganisms.

  • Bacteria (Haemophilus): Hib most common. Other Haemophilus species (e.g. A, F) can occur.
  • Bacteria (Non-Haemophilus): Group A Streptococcus, Staphylococcus and Neisseria meningitidis.
  • Viruses: Human herpes virus, Parainfluenza virus, Influenza B virus.
  • Fungal: Consider if immunocompromised. Candidia spp. Aspergillus spp.
  • Non-infectious: Inflammation may occur due to trauma, causes include thermal injury and ingestion of caustic substances. Other rare causes include graft vs host disease and systemic granulomatous conditions.

Pathophysiology

Acute epiglottitis may be due to direct invasion of the mucosal layer by microorganisms.

Infectious microorganisms may lead to acute inflammation of the epiglottitis from direct invasion or spread via bacteraemia. Typically, bacteria (most common cause) reside in the nasopharynx and infiltrate the epiglottis mucosa through defects (i.e. microtrauma). 

Defects in the mucosa may occur due to a preceding viral illness or direct trauma from swallowing food. As inflammation and swelling begins, it rapidly leads to infection of the entire supraglottic airways leading to potentially life-threatening airway obstruction.

Epiglottis anatomy

Clinical features

Acute epiglottitis is a medical emergency that can present with severe respiratory distress and stridor.

Children with acute epiglottitis classically present with the three ‘D’s’: Dysphagia, drooling, distress (respiratory). Cough is usually lacking (or a less prominent feature) and more characteristic of croup. Other features can include:

  • Fever
  • Sore throat 
  • Restless and irritable
  • ‘Hot potato’ voice
  • ‘Tripod’ positioning: leaning forward, hyperextended neck, chin forward (maximise airflow)
  • Stridor

Diagnosis & investigations

Acute epiglottitis requires rapid assessment and clinical diagnosis to prevent further airway compromise.

There should be a low threshold for the suspicion of acute epiglottitis due to risk of rapid deterioration. Diagnosis is based on visualisation of the of the inflamed epiglottis, however, this should only be attempted by a clinician who is trained to deal with a paediatric airway. 

Inflamed epiglottis, suggestive of acute epiglottitis. Image courtesy of Wikimedia commons.

 

There is concern that attempts to visualisation of the back of the throat by an untrained clinician could lead to cardiorespiratory arrest by a variety of mechanisms (e.g. functional obstruction, laryngospasm). Therefore, if a child has classical signs of epiglottitis prompt involvement of a clinician with paediatric airway skills is needed before visualisation. This is so an airway can be secured if deterioration during, or after, visualisation occurs.

Other investigations

The initial priority is airway management. Subsequent investigations may include blood tests, blood cultures, epiglottic cultures (only if airway secure), or imaging. Imaging may have a role (e.g. MRI/CT for suspected abscess). Lateral radiographs of the neck can be used to look for oedema of the epiglottis, but direct visualisation is the standard of care.

Management

The priority of acute epiglottitis treatment is airway management by an experienced clinician trained in paediatric airways.

The key aspects of treatment include airway management and antibiotics.

  • Airway management: clinician with paediatric airway skills. Maintain oxygenation. Intubation if respiratory arrest or compromise. Do NOT use supraglottic airways.
  • Antibiotics: refer to local guidelines. Intravenous if airway concerns. Generally broad-spectrum (e.g. third-generation cephalosporin).
  • Other measures: try to prevent agitation of child. Referral to paediatric intensive care unit. Monitor for complications (e.g. abscess), will need reassessment of epiglottis prior to extubation

Vaccination

All children should have the Hib vaccination as part of the usual childhood vaccination programme. This has dramatically decreased the incidence of acute epiglottitis.

Complications

Prognosis is good when the diagnosis and treatment of acute epiglottitis are instigated promptly.

Complications may include abscess formation, sepsis, respiratory arrest and death. Early recognition and treatment can prevent need for intubation and development of complications. 

 


Updated: June 2020 by Benjamin Norton

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