Definition

Laryngitis is caused by inflammation of the larynx, resulting in hoarseness of the voice.

  Description

When air is breathed in (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 vocal cords, responsible for setting up the vibrations necessary for speech, are located within the larynx. 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 which 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 must be 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 substances from entering the airway.

In laryngitis, the tissues below the level of the epiglottis are swollen and inflamed. This causes swelling around the area of the vocal cords, so that they cannot vibrate normally. A hoarse sound to the voice is very characteristic of laryngitis. Laryngitis is a very common problem, and often occurs during the course of an upper respiratory tract infection (cold).

  Causes and symptoms

Laryngitis is caused almost 100% of the time by a virus. The same viruses which cause the majority of simple upper respiratory infections (colds, etc.) are responsible for laryngitis. These include parainfluenzae virus, influenza virus, respiratory syncytial virus, rhinovirus, coronavirus, and echovirus. Extremely rarely, bacteria such as Group A streptococcus, M. catarrhalis, or that which causes tuberculosis may cause laryngitis. In people with faulty immune systems (particular due to acquired immunodeficiency syndrome, or AIDS), infections with fungi may be responsible for laryngitis.

Symptoms usually begin along with, or following, symptoms of a cold. A sore, scratchy throat, fever, runny nose, achiness, and fatigue may all occur. Difficulty swallowing sometimes occurs with streptococcal infections. The patient may cough and wheeze. Most characteristically, the patient's voice will sound strained, hoarse, and raspy.

In extremely rare cases, the swelling of the larynx may cause symptoms of airway obstruction. This is more common in infants, because the diameter of their airways is so small. In that case, the baby may have a greatly increased respiratory rate, and exhibit loud high-pitched sounds with breathing (called stridor).

  Diagnosis

Diagnosis is usually made by learning the history of a cold followed by hoarseness. The throat usually appears red and somewhat swollen. Listening to the chest and back with a stethoscope may reveal some harsh wheezing sounds with inspiration (breathing in).

In long-standing (chronic laryngitis), tuberculosis may be suspected. Using a scope called a laryngoscope, examination of the airway will show redness, swelling, small bumps of tissue called nodules, and irritated pits in the tissue called ulcerations. Special skin testing (TB testing) will reveal that the individual has been exposed to the bacteria causing TB.

  Treatment

Treatment of a simple, viral laryngitis simply addresses the symptoms. Gargling with warm salt water, pain relievers such as acetaminophen, the use of vaporizers to create moist air, and rest will help the illness resolve within a week.

In an infant who is clearly struggling for air, it may be necessary to put in an artificial airway for a short period of time. This is very rarely needed.

An individual with tubercular laryngitis is treated with a combination of medications used to treat classic TB. In people with fungal laryngitis, a variety of anti-fungal medications are available.

  Alternative treatment

Alternative treatments include aromatherapy inhalations made with benzoin, lavender, frankincense, thyme, and sandalwood. Decoctions (extracts made by boiling an herb in water) or infusions (extracts made by steeping an herb in boiling water) can be made with red sage (Salvia officinalis var. rubra) and yarrow (Achillea millefolium) or with licorice (Glycyrrhiza glabra). These are used for gargling, and are said to reduce pain. Echinacea ( Echinacea spp.) tincture taken in water every hour for 48 hours is recommended to boost the immune system. Antiviral herbs, including usnea (Usnea spp.), lomatium (Lomatium dissectum), and ligusticum (Ligusticum porteri), may help hasten recovery from laryngitis. Homeopathic remedies are recommended based on the patient's symptoms. Some people may get relief from placing cold compresses on the throat.

  Prognosis

Prognosis for laryngitis is excellent. Recovery is complete, and usually occurs within a week's time.

  Prevention

Prevention of laryngitis is the same as for any upper respiratory infections. The only way to even attempt to prevent such illnesses is by good handwashing, and by avoiding situations where one might come in contact with people who might be sick. However, even with relatively good hygiene practices, most people will get about five to six colds per year. It is unpredictable which of these may lead to laryngitis.

   Key Terms:

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. Larynx The part of the airway lying between the pharynx and the trachea. Nasopharynx The part of the airway into which the nose leads. Oropharynx The part of the airway into which the mouth leads. Trachea The part of the airway which leads into the bronchial tubes.

   Resources:

Books

• Durand, Marlene, et al. "Laryngitis, Croup, and Epiglottitis." In Harrison's Principles of Internal Medicine, ed. Anthony S. Fauci, et al. New York: McGraw-Hill, 1997.
• Orenstein, David. "Acute Inflammatory Upper Airway Obstruction." In Nelson Textbook of Pediatrics, ed. Richard E. Behrman. Philadelphia: W. B. Saunders Co., 1996.
• Ray, C. George. "Middle and Lower Respiratory Tract Infections." In Sherris Medical Microbiology: An Introduction to Infectious Diseases. 3rd ed. Ed. Kenneth J. Ryan. Norwalk, CT: Appleton & Lange, 1994.
• Stoffman, Phyllis. The Family Guide to Preventing and Treating 100 Infectious Diseases. New York: John Wiley & Sons, 1995.

Organizations

• American Academy of Otolaryngology-Head and Neck Surgery, Inc. One Prince St., Alexandria VA 22314-3357. (703) 836-4444. http://www.entnet.org