Definition
Acute laryngitis is inflammation or swelling of the vocal cords in response to an infection, irritation or damage (trauma).
Incidence/Age
Most people have experienced acute laryngitis at some point in their lives, usually in association with the common cold or prolonged shouting. It can occur at any age from childhood to old age.
Relevant Applied Anatomy And Physiology
The vocal cords are covered with a delicate and very thin, elastic layer of skin. This allows it to vibrate and produce the sound of the voice. Normally the pitch of the voice is changed by stretching the vocal cords and altering their shape.
In acute laryngitis the vocal cords become thicker and stiffer and so do not vibrate as well. More effort is required to get the vocal cords to vibrate and it is far more difficult to control the pitch and loudness of the voice. The voice becomes hoarse or disappears into a whisper. It is also often too painful to speak in acute laryngitis because of the swelling and inflammation of the vocal cords.
The vocal folds collide on average 120 times a second in men during speech and 220 times a second in women. Imagine rubbing a sore on the skin repeatedly - no wonder it is often too painful to speak!
Causes
The most common cause is a viral infection as part of the common cold. Occasionally, it can be due to a bacterial infection and associated with other infections of the nose (Rhinosinusitis), throat (tonsillitis, pharyngitis) and lungs (pneumonia).
Patients who take inhaled steroids for asthma are more prone to getting fungal laryngitis due to an infection with Candida (Thrush). This is a rare cause of hoarseness in inhaler-users and it is important that the patient seeks the attention of his/her doctor if it persists for more than a couple of weeks.
Other causes of laryngitis include exposure to acid reflux from the stomach or damage to the vocal cords from shouting. Mild laryngitis often occurs after talking for long periods of time in a noisy atmosphere. Pubs and clubs usually have loud background music which means that it is necessary to raise the voice in order to be heard. In addition the atmosphere is often smoky causing further irritation of the vocal cords.
Symptoms And Signs
The throat at the level of the voice box may feel dry and uncomfortable and in more severe cases it may also be painful to speak.. The voice can vary from mild huskiness and sounding deeper to being squeaky and weak. In more severe cases the patient may be unable to speak at all ('aphonia').
In mild cases the vocal cords may look slightly red, swollen and dull in colour but in severe cases a white film of dead skin cells and bacteria ('slough') forms on the surface.
Fungal infections cause a white speckled appearance to the vocal cords and it is not uncommon for the rest of the throat and mouth to also be affected.
Very young children may develop an abnormal cry, shortness of breath and, in severe cases, noisy breathing ('stridor'). This is because the breathing passages are narrower in this age group and it doesn't require much swelling to cause a serious degree of narrowing of the air passages. Often laryngitis in this age group is also accompanied by infections in the windpipe (trachea) and the lungs such as croup or laryngotracheo-bronchitis. These conditions are particularly serious and require immediate medical attention
Written by Medpages Editorial Team
Last Editorial Review:10/1/2010
