Epiglottitis

Epiglottitis is a potentially life-threatening infection causing inflammation and swelling of the epiglottis (the flap of cartilage at the back of the tongue that closes off the windpipe during swallowing). The swollen epiglottis obstructs breathing and can cause death by suffocation if the condition is not treated promptly. Epiglottitis is also known as supraglottitis. 

Epiglottitis is now rare due to the routine immunization of infants against Haemophilus influenzae, the bacterium that causes the condition.

Note on airway obstruction and stridor

Of all emergencies seen in otolaryngologic practice, diagnosing and managing airway obstruction is one of the most complex, needing multiprofessional input and an experienced team to achieve good outcomes. The upper airway can be obstructed by a range of disease processes, from pathology in the anterior nasal cavity to the lower airways. Problems associated with breathing usually present as nasal obstruction, stertor and stridor.

Epiglottitis/Supraglottitis

Haemophilus influenzae type B is the usual infective agent, although the incidence has significantly decreased with HiB vaccination. Children between the ages of 2 and 7 years of age are affected, with a peak incidence in 3-year-olds.

The disease typically presents with a rapid onset of high fever, toxicity, agitation, stridor, dyspnoea, muffled voice and painful swallowing. Examination will reveal a child seated and leaning forward with the mouth open and drooling.

If supraglottitis is suspected, no further examination is recommended outside of a controlled setting.

In acute supraglottitis, the risk of complete obstruction is high and the airway has to be secured. Endotracheal intubation is the method of choice as the supraglottic swelling is usually reversible in a few days, unless complications occur.

An oedematous, cherry-red epiglottis with inflammation of the surrounding supraglottis is seen on direct laryngoscopy (Picture 1).

Epiglottitis picture -Laryngoscopic view of oedematous and red epiglottis, with generalised oedema of supraglottic.

Picture 1: Laryngoscopic view of oedematous and red epiglottis, with generalised oedema of supraglottic.

Intravenous antibiotics are required.

Stridor in children

Evaluation

A careful history provides useful pointers to the diagnosis (Bullet list 1).

Bullet list 1: Historical information

  • Age of onset
  • Duration/phase of stridor
  • Worsening/improvement of stridor since onset
  • Precipitating causes
  • Failure to gain weight
  • Breath-holding spells
  • Fever
  • Feeding /swallowing problems
  • Hoarse/muffled voice
  • Intubation in the past
  • Cough/chest infections

A previously well child presenting with acute onset stridor should arouse suspicions of foreign body aspiration. A preceding upper respiratory tract infection (URTI) indicates croup or bacterial tracheitis.

Epiglottitis (supraglottitis) typically presents as rapid onset fever, dysphagia and drooling in children aged between 2 and 7 years. The child with acute stridor is ideally assessed in a setting where instrumentation and experienced personnel are available for emergency intervention to secure and stabilise the airway. The areas that clinical assessment should cover are shown in Bullet list 2.

Bullet list 2: Clinical evaluation

  • Respiratory rate
  • Cyanosis
  • Apnoeic spells
  • Use of accessory muscles
  • Intercostal/sternal retraction
  • Nasal flaring
  • Timing/severity of stridor
  • Hoarseness
  • Temperature/toxicity
  • Level of consciousness
  • ENT examination in controlled setting

Respiratory rate and level of consciousness are the most important indicators of severity of obstruction. Increasing intensity of the sound is not an indicator of the severity, as in severe obstruction the airflow is significantly diminished and thus no stridor may be heard.

Measures should be taken not distress the child further for fear of precipitating an acute obstruction. This includes keeping the parent or carer at all times with the child, until the airway is secure. With increasing hypoxia and carbon dioxide retention, the child can become drowsy and unresponsive.

A working diagnosis of the cause of obstruction can be made in the majority of cases before direct examination of the airway. Most of these conditions are in the evolving phase when initially seen, and if observation only is planned, this is best done in an intensive care or high-dependency setting where rapid intervention is possible if the patient deteriorates.

Congenital structural lesions rarely present in the acute setting. For children with chronic stridor a diagnostic laryngotracheoscopy will be required in the majority of patients, unless the condition is mild and readily diagnosed on clinical examination alone. In the cooperative child with no evidence of hypoxia, flexible laryngoscopy in the clinic can be very informative. Surgical treatment is usually necessary for chronic obstruction that doesn’t respond to conservative treatment.

Epiglottitis in more detail - technical

Epiglottitis is a life-threatening bacterial infection of the supraglottic mucosa that can lead to the rapid onset of toxic symptoms and airway compromise, often necessitating emergent airway management in addition to appropriate antibiotic therapy.

Etiology

Epiglottitis is the result of bacterial cellulitis of the supraglottic structures, particularly the lingual surface of the epiglottis but spreading rapidly to involve the arytenoid soft tissues, aryepiglottic folds, and even surrounding hypopharyngeal tissues. With progressive edema, the epiglottis is forced posteriorly leading to glottic obstruction. Haemophilus influenzae type B (HIB) is the most commonly implicated organism, however in the post-vaccination era group-A b hemolytic Streptococcus, Staphylococci, Pneumococci, Klebsiella, and Pseudomonas are becoming more likely bacterial agents. Candida and viruses such as herpes simplex type 1, varicella zoster, and parainfluenza have been isolated in directed cultures and should trigger concern for immunodeficiency. Thermal epiglottitis has been reported after ingestion of hot food or liquid and after smoking or other inhalational injury, however such etiologies are more common in adult populations.

Clinical Presentation

Epiglottitis tends to occur in children aged 2 to 7 years, although cases in adults and children less than 1 year of age have been reported (Stroud and Friedman 2001). Incidence has shifted towards older children since the introduction of the HIB vaccination, however peak incidence remains at age 3.5 years (Shah 2011). Patients are toxic in appearance, with a fulminant presentation of acute and rapidly progressive throat pain, fever, and respiratory distress. Sore throat may manifest as refusal to eat in young children. Patients will have difficulty tolerating secretions due to odynophagia, and voices will be muffled.

The classic presentation of the “3 D’s” (drooling, dysphagia, and distress) is generally apparent. Intraoral examination, though not recommended without full preparation for airway compromise, may demonstrate a “cherry red” epiglottis extending above the tongue base into the oropharynx. With disease progression, children are classically described in the “tripod position,” upright with the chin up, mouth open, tongue protruding, and bracing themselves with their hands (Shah 2011).

Stridor, when present, represents late disease with impending complete airway obstruction as supraglottic involvement generally spreads first from the epiglottis sequentially to the aryepiglottic folds inferiorly. Notably, cough is not a significant component of disease presentation but when present is usually quite painful. Exquisite tenderness of the laryngotracheal complex, especially in the region of the hyoid bone, should raise strong suspicion for acute epiglottitis. The duration of disease prior to hospital presentation may be as short as a few hours but is almost always less than 24 hours.

Diagnostics

Diagnosis is strongly suggested by history and physical examination. Once suspected, a physician capable of controlling the airway via intubation and surgical intervention should be made available. If the patient is clinically stable and the diagnosis is in question, radiographic study via a lateral soft tissue neck film may help to narrow the differential diagnosis and classically demonstrates the “thumb sign” with a round, thickened epiglottis and thickened aryepiglottic folds.

AP examination demonstrates normal subglottic caliber, in contrast with croup (John et al. 2006). Patients should not be forced into a supine position as gravity-dependent repositioning of the epiglottis may lead to even more rapid clinical decline. Without reports to validate their safety, anxiety provoking maneuvers such as intraoral examination with or without a tongue blade, fiberoptic laryngoscopy, or phlebotomy, should be avoided as they are anecdotally known to precipitate laryngospasm.

Nevertheless, diagnosis is ultimately confirmed only by visualization of the supraglottic structures. For patient safety, direct laryngoscopy is best performed under the controlled conditions of the operative suite for comprehensive airway management. The epiglottis is classically described as “cherry red.” This erythema and edema of the epiglottis spreads to involve the aryepiglottic folds and arytenoids with diffuse obscuration of landmarks. Oropharyngeal tissues are rarely if ever involved. Laboratory studies, such as CBC, CRP, ESR, blood cultures, and culture of the supraglottic tissue, will demonstrate signs of acute infection but should be pursued only after airway security is ensured.

Systemic evaluation should not be overlooked, as 50 % of patients diagnosed with epiglottitis will have extra-epiglottic infection including meningitis, otitis media, pneumonia, and cellulitis (Sulman and Hollinger 2006).

Differential Diagnosis

Congenital lesions (congenital lesions of the larynx, trachea, and esophagus), namely severe laryngomalacia, may cause airway obstruction in a similar fashion but has a markedly different clinical presentation that is less acute, non-toxic, and generally improves with positional change. Laryngopharyngeal reflux (laryngology / swallowing / reflux) may contribute to supraglottic edema but also does not present with the acuity of epiglottitis. Infectious lesions that may present with supraglottic airway compromise include laryngeal papillomatosis, peritonsillar abscess, deep neck infection, and diphtheria. Caustic ingestion and thermal injury may present with acute supraglottic airway inflammation and obstruction. Foreign body ingestion (Foreign bodies of the esophagus and airway) may obstruct the supraglottic airway but would not present with the toxic signs of epiglottitis. Finally, angioneurotic edema of the epiglottis may occur due to an allergic reaction or a congenital C-1 esterase deficiency (Schwartz 2008).

Prophylaxis

HIB vaccination is the strongest means of prophylaxis, and recent studies have demonstrated a dramatic decrease in the number of cases of epiglottitis since the vaccine’s introduction in the 1980’s. It works by stimulating production of antibodies to the polysaccharide capsule of HIB. The reported incidence of epiglottitis has decreased from 3.47 cases per 100,000 children in 1980 to 0.63 cases per 100,000 children in 1990 (Stewart 2006). Overall, the incidence of invasive HIB disease, including epiglottitis and meningitis, has decreased by 95%in the United States. Amongst immunized populations, the epidemiology of documented cases has shifted towards other organisms with group A streptococcus the most common (Duncan 2010).

Therapy

Once the diagnosis is suspected, endoscopy should be performed as quickly as possible and can be both diagnostic and therapeutic by establishing a secure airway. An otolaryngologist, anesthesiologist, and intensivist should be immediately involved in care. Rigid telescopes, rigid bronchoscopes, and tracheotomy supplies should be immediately available. Some prefer nasotracheal intubation is preferred to orotracheal intubation. Tracheotomy was classically performed in all patients diagnosed with epiglottitis, however a secure endotracheal tube is the preferred option in the era of modern airway management and antibiotic therapy. Tracheotomy is reserved for cases in which oral or nasal intubation proves impossible.

Once the airway is secured, specimens should be taken from the epiglottis for culture and sensitivity. Antibiotic therapy and intensive care monitoring and support then follow. Ceftriaxone, cefuroxime, or ampicillin / sulbactam are viable empiric antibiotic choices and should be adjusted according to culture results. Vancomycin may be employed in children who are sensitive to penicillin or cephalosporins. The use of steroids to decrease inflammation has been suggested but is not supported by any prospective studies. Extubation is appropriate when the patient has a cuff leak or more safely after repeat endoscopy reveals resolution of supraglottic edema. Intubation generally is required for 24 to 48 hours. Oral antibiotics based upon culture results should be employed to complete a 7 to 10 day course of treatment.

Prognosis

With a secure airway, prognosis is generally excellent with a rapid response to antibiotics and extubation after about 48 to 72 hours of therapy. Evidence exists that when group A streptococcus is the causative organism, disease resolution occurs more slowly with a mean intubation time of 6 to 7.5 days as compared to 1.5 to 3 days as seen in HIB (Stewart 2006).