Introduction
Epiglottitis is a rapidly developing inflammation of the epiglottis and adjacent tissues, usually due to a bacterial infection, that can cause life-threatening airway obstruction.
Historically, epiglottitis was a disease of childhood, and the most common pathogen was Haemophilus influenzae type b (Hib). After the introduction of the Hib vaccine in 1985, followed by the recommendation of routine infant vaccination in the United States beginning in 1991, the incidence of epiglottitis dramatically declined in children.1,2,3,4,5,6,7
Today, there is no predominant pathogen implicated in epiglottitis. Hib epiglottis is still occasionally seen, accounting for 6 out of 19 cases in a series (from 1992 to 2002) by Shah and colleagues.5 It occurs in vaccinated and nonvaccinated patients, because the vaccine is not 100% effective.
Image in a 66-year-old patient with acute epiglottitis. The epiglottis (E) is swollen and its appearance is thumblike rather than petal-like. The aryepiglottic folds (A) also are swollen and are more radiopaque than normal.
Computed tomography (CT) scan in an adult with acute epiglottitis shows a column of air around the epiglottis (E). The right side is more swollen than the left, and the hypo-attenuating area (A) is suggestive of fluid or the early formation of an abscess.
In addition to Hib, bacterial culprits include groups A beta-hemolytic streptococci, particularly Streptococcus pyogenes and S pneumoniae, as well as Staphylococcus aureus. Rare causes include H parainfluenzae, influenza B viruses, herpes simplex virus (HSV), and H influenzae (including type A and type F, as well as nontypeable strains). Infrequently, thermal injury from the consumption of hot liquids, corrosive ingestion, and various lymphoproliferative disorders have been implicated as noninfectious causes of epiglottitis.
Patient Education
For excellent patient education resources, visit eMedicine's Esophagus, Stomach, and Intestine Center. Also, see eMedicine's patient education article Epiglottitis.
Related eMedicine topics:
Epiglottitis [Pediatrics: General Medicine]
Epiglottitis, Adult
Pediatrics, Epiglottitis
Pathophysiology
The epiglottis is a thin cartilage covered by a loose layer of stratified squamous epithelium, which creates a potential space. When infection ensues, this potential space expands with inflammatory cells and fluid, and curls posteriorly over the glottic opening, acting as a ball-valve type of airway obstruction during inspiration.
Associated swelling of the aryepiglottic folds and arytenoids is frequently seen in children and adults. In adults, the soft palate, base of the tongue, uvula, and vallecula are commonly involved as well, often resulting in supraglottitis.8
Frequency
United States
The incidence of epiglottitis in children has greatly declined since Hib vaccine came into widespread use, although the vaccine is not 100% effective.1 In children younger than 5 years, the incidence has decreased from approximately 10 cases per 10,000 in the pre-vaccine era to 0.3 cases per 10,000 between 1995 and 2003. In contrast, the incidence of acute epiglottitis has increased in adults, with the reported incidence rising from 0.79 cases per 100,000 in 1986, to 1.8 per 100,000 in 1990, and to 3.1 per 100,000 in 2000.7,9
International
A similar decline in incidence of childhood Hib epiglottitis was seen in other countries following the introduction of routine Hib vaccination.
Mortality/Morbidity
The majority of the morbidity and mortality associated with epiglottitis is caused by life-threatening airway obstruction requiring intubation and occasionally tracheostomy. Epiglottitic swelling causing greater than 50% airway obstruction, or extension of swelling to the arytenoids, generally requires immediate intervention. Other complications include the development of an abscess, acute tonsillitis, or bacteremia.
The mortality rate is around 1% in children; the rate is 6-7% in adults, which may be partially attributable to a greater difficulty and delay in diagnosing epiglottitis in adults.10
Sex
Epiglottitis is more common in males than in females, with a male-to-female ratio of about 3:1.
Age
- Before widespread use of the Hib vaccine, epiglottitis occurred mainly in young children, peaking between 2 and 7 years of age. The disease is now rare in children, but when it occurs, it is seen in older children with a mean age of 11.6 years.5
- Epiglottitis is now more common in adults, accounting for approximately 60-70% of diagnosed cases.1,2,3,7
Anatomy
The epiglottis is a small flap of tissue in the larynx that guards the airway entrance to the lungs. The larynx also contains the arytenoid cartilages, aryepiglottic folds, vocal cords, and cricoid cartilage.
Presentation
The most common symptoms of epiglottitis include a severe sore throat, odynophagia, drooling (due to inability to swallow), and stridor. Classically, the patient appears anxious and may lean forward, extending his/her neck in an attempt to maintain an open airway. Dyspnea, drooling, a muffled voice, and the rapid onset of symptoms are predictors of impending airway obstruction.2 In children with Hib, the onset is often sudden and progresses rapidly; the disease usually follows a more indolent course in adults, and delayed airway obstruction can occur several days after admission.
Preferred Examination
Findings on lateral neck radiographs are frequently diagnostic. A single, lateral, upright view of the neck in extension, preferably with a closed mouth, is usually adequate. The radiograph should be obtained with portable equipment in the emergency department (ED), because acute airway obstruction may occur at any time. In severe cases, radiographs should not be acquired until the airway is secured.
The diagnosis can be confirmed by direct nasopharyngolaryngoscopy, which should be performed only when measures to immediately secure the airway are available in the ED or operating room.
Limitations of Techniques
An inability to hyperextend the patient's neck because of irritability may interfere with diagnostic accuracy. An image obtained with the patient's mouth open may decrease the probability of seeing true obliteration of the vallecula. Direct examination of the pharynx or anxiety caused by diagnostic tests may precipitate acute airway obstruction. If crying occurs, rapid inspiration through the swollen epiglottis can cause the airway to close completely. Finally, a suboptimally low kilovolt setting may cause poor depiction of the soft tissues.
Differential Diagnoses
| Anaphylaxis | Peritonsillar Abscess |
| Bacterial Tracheitis | Pertussis |
| Croup | Pharyngitis |
| Diphtheria | Retropharyngeal Abscess |
| Mononucleosis |
Other Problems to Be Considered
Angioneurotic edema
Caustic insult
Foreign bodies
Quinsy
Acute spasmodic laryngitis (spasmodic croup)
Hypocalcemic tetany
Psychogenic stridor
More on Epiglottitis, Acute |
 Overview: Epiglottitis, Acute |
| Imaging: Epiglottitis, Acute |
| Follow-up: Epiglottitis, Acute |
| Multimedia: Epiglottitis, Acute |
| References |
| Further Reading |
| Next Page » |
References
Faden H. The dramatic change in the epidemiology of pediatric epiglottitis. Pediatr Emerg Care. Jun 2006;22(6):443-4. [Medline].
Mayo-Smith MF, Spinale JW, et al. Acute epiglottitis. An 18-year experience in Rhode Island. Chest. Dec 1995;108(6):1640-7. [Medline]. [Full Text].
Murrage KJ, Janzen VD, Ruby RR. Epiglottitis: adult and pediatric comparisons. J Otolaryngol. Jun 1988;17(4):194-8. [Medline].
Progress toward elimination of Haemophilus influenzae type b invasive disease among infants and children--United States, 1998-2000. MMWR Morb Mortal Wkly Rep. Mar 22 2002;51(11):234-7. [Medline]. [Full Text].
Shah RK, Roberson DW, Jones DT. Epiglottitis in the Hemophilus influenzae type B vaccine era: changing trends. Laryngoscope. Mar 2004;114(3):557-60. [Medline].
McConnell A, Tan B, Scheifele D, et al. Invasive infections caused by Haemophilus influenzae serotypes in twelve Canadian IMPACT centers, 1996-2001. Pediatr Infect Dis J. Nov 2007;26(11):1025-31. [Medline].
Guldfred LA, Lyhne D, Becker BC. Acute epiglottitis: epidemiology, clinical presentation, management and outcome. J Laryngol Otol. Sep 25 2007;1-6. [Medline].
Berger G, Averbuch E, Zilka K, et al. Adult vallecular cyst: thirteen-year experience. Otolaryngol Head Neck Surg. Mar 2008;138(3):321-7. [Medline].
Berger G, Landau T, Berger S, et al. The rising incidence of adult acute epiglottitis and epiglottic abscess. Am J Otolaryngology. 2003;24:374-83. [Medline].
MayoSmith MF, Hirsch PJ, Wodzinski SF, et al. Acute epiglottitis in adults. An eight-year experience in the state of Rhode Island. N Engl J Med. May 1 1986;314(18):1133-9. [Medline].
Schumaker HM, Doris PE, Birnbaum G. Radiographic parameters in adult epiglottitis. Ann Emerg Med. Aug 1984;13(8):588-90. [Medline].
Ducic Y, Hébert PC, MacLachlan L, et al. Description and evaluation of the vallecula sign: a new radiologic sign in the diagnosis of adult epiglottitis. Ann Emerg Med. Jul 1997;30(1):1-6. [Medline].
Nemzek WR, Katzberg RW, Van Slyke MA, et al. A reappraisal of the radiologic findings of acute inflammation of the epiglottis and supraglottic structures in adults. AJNR Am J Neuroradiol. Mar 1995;16(3):495-502. [Medline]. [Full Text].
Rothrock SG, Pignatiello GA, Howard RM. Radiologic diagnosis of epiglottitis: objective criteria for all ages. Ann Emerg Med. Sep 1990;19(9):978-82. [Medline].
Further Reading
Movement of Epiglottis During Swallowing
Difficult Airway Society guidelines for management of the unanticipated difficult intubation. Difficult Airway Society - Medical Specialty Society. 2004 Jul. 20 pages. NGC:003982
Keywords
acute epiglottitis, supraglottitis, cherry-red epiglottitis, Haemophilus influenzae type b, Hib, Streptococcus pneumoniae, Staphylococcus aureus, Streptococcus pyogenes, group A beta-hemolytic streptococci, herpes simplex virus, HSV
