When air is inhaled (inspired), it passes through the nose and the nasopharynx or through the mouth and the oropharynx. These are both connected to the larynx, a tube made of cartilage. The air continues down the larynx to the trachea. The trachea then splits into two branches, the left and right bronchi (bronchial tubes). These bronchi branch into smaller air tubes that run within the lungs, leading to the small air sacs of the lungs (alveoli).
Either food, liquid, or air may be taken in through the mouth. While air goes into the larynx and the respiratory system, food and liquid are directed into the tube leading to the stomach, the esophagus. Because food or liquid in the bronchial tubes or lungs could cause a blockage or lead to an infection, the airway is protected. The epiglottis is a leaf-like piece of cartilage extending upwards from the larynx. The epiglottis can close down over the larynx when someone is eating or drinking, preventing these food and liquids from entering the airway.
Epiglottitis is an infection and inflammation of the epiglottis. Because the epiglottis may swell considerably, there is a danger that the airway will be blocked off by the very structure designed to protect it. Air is then unable to reach the lungs. Without intervention, epiglottitis has the potential of being fatal. Because epiglottitis involves swelling and infection of tissues, which are all located at or above the level of the epiglottis, it is sometimes referred to as supraglottitis (supra meaning above). About 25 percent of all children with this infection also have pneumonia.
In the twentieth century, epiglottitis was primarily a disease of two- to seven-year-old children, with boys twice as likely to become ill as girls. In the early 2000s vaccines have greatly reduced the incidence of Haemophilus influenzae type b (Hib) epiglottitis, and the disease is more frequently seen in adults. In children, epiglottitis is an incredibly rare disease, thanks to timely Hib vaccination in childhood.
Causes and symptoms
The most common cause of epiglottitis is infection with the bacteria called Haemophilus influenzae type b. Other types of bacteria are also occasionally responsible for this infection, including some types of Streptococcus bacteria and the bacteria responsible for causing diphtheria.
A patient with epiglottitis typically experiences a sudden fever and begins having severe throat and neck pain. Because the swollen epiglottis interferes significantly with air movement, every breath creates a loud, harsh, high-pitched sound referred to as stridor. Because the vocal cords are located in the larynx just below the area of the epiglottis, the swollen epiglottis makes the patient's voice sound muffled and strained. Swallowing becomes difficult, and the patient may drool. The patient often leans forward and juts out his or her jaw, while struggling for breath.
Epiglottitis strikes suddenly and progresses quickly. A child may begin complaining of a sore throat and within a few hours be suffering from extremely severe airway obstruction.
Diagnosis begins with a high level of suspicion that a quickly progressing illness with fever, sore throat, and airway obstruction is very likely to be epiglottitis. If epiglottitis is suspected, no efforts should be made to look at the throat or to swab the throat in order to obtain a culture for identification of the causative organism. These maneuvers may cause the larynx to go into spasm (laryngospasm), completely closing the airway. These procedures should only be performed in a fully equipped operating room, so that if laryngospasm occurs, a breathing tube can be immediately placed in order to keep the airway open.
An instrument called a laryngoscope is often used in the operating room to view the epiglottis, which will appear cherry-red and quite swollen. An x ray picture taken from the side of the neck should also be obtained. The swollen epiglottis has a characteristic appearance, called the "thumb sign."
Treatment almost always involves the immediate establishment of an artificial airway: inserting a breathing tube into the throat (intubation) or making a tiny opening toward the base of the neck and putting a breathing tube into the trachea (tracheostomy). Because the patient's apparent level of distress may not match the actual severity of the situation, and because the disease's progression can be quite surprisingly rapid, it is preferable to go ahead and place the artificial airway, rather than adopting a wait-and-see approach.
Because epiglottitis is caused by a bacteria, antibiotics such as cefotaxime, ceftriaxone, or ampicillin with sulbactam should be given through a needle placed in a vein (intravenously). This prevents the bacteria that are circulating throughout the bloodstream from causing infection elsewhere in the body.
Epiglottis—A leaf-like piece of cartilage extending upwards from the larynx, which can close like a lid over the trachea to prevent the airway from receiving any food or liquid being swallowed.
Extubation—The removal of a breathing tube.
Intubation—A procedure in which a tube is inserted through the mouth and into the trachea to keep the airway open and to help a patient breathe.
Laryngospasm—Spasmodic closure of the larynx.
Larynx—Also known as the voice box, the larynx is the part of the airway that lies between the pharynx and the trachea. It is composed of cartilage that contains the apparatus for voice production–the vocal cords and the muscles and ligaments that move the cords.
Nasopharynx—One of the three regions of the pharynx, the nasopharynx is the region behind the nasal cavity.
Oropharynx—One of the three regions of the pharynx, the oropharynx is the region behind the mouth.
Supraglottitis—Another term for epiglottitis.
Trachea—The windpipe. A tube composed of cartilage and membrane that extends from below the voice box into the chest where it splits into two branches, the bronchi, that lead to each lung.
Tracheostomy—A procedure in which a small opening is made in the neck and into the trachea or windpipe. A breathing tube is then placed through this opening.
With treatment (including the establishment of an artificial airway), only about 1 percent of children with
Prevention involves the use of a vaccine against H. influenzae type b (called the Hib vaccine). It is given to babies at two, four, six, and 15 months. Use of this vaccine has made epiglottitis a very rare occurrence.
Parents should be aware of the advantages of the Hib vaccine. They should also call the doctor immediately if a child has a sudden, high fever and neck or throat pain.
Long, Sarah S., et al, eds. Principles and Practice of Pediatric Infectious Diseases, 2nd ed. St. Louis, MO: Elsevier, 2003.
Roosevelt, Genie E. "Acute Inflammatory Upper Airway Obstruction." In Nelson Textbook of Pediatrics. Edited by Richard E. Behrman et al. Philadelphia: Saunders, 2004.
American Academy of Otolaryngology-Head and Neck Surgery Inc. One Prince St., Alexandria VA 22314–3357. Web site: <www.entnet.org>.
Rosalyn Carson-DeWitt, MD