Stridor
Stridor is a general term that simply means noisy breathing. It is usually caused by an obstruction or narrowing in your child's upper airway, which includes the following structures:
- Larynx (voice box) - is a cylindrical structure of cartilage, muscles, and soft tissue which contains the vocal cords. The vocal cords are the upper opening into the windpipe (trachea), the passageway to the lungs.
- Trachea (windpipe) - a tube that carries air from the larynx to the lungs.
- Bronchi - the tubes that carry air to the lungs (like the branches of a tree).
Most commonly stridor is heard when the child breathes in (inspiration) and the obstruction is in the larynx. Stridor heard when the child breathes out (expiration) — wheezing — is usually due to a narrowing of the airway in the chest. This is often mistaken for asthma.
Causes of stridor
There are many different causes of stridor. Most are problems with the structure of the child's airway. The upper airway in children is shorter and narrower than that of an adult, and, therefore, more likely to lead to problems with obstruction. The following are some of the more common causes of stridor in children:
- Laryngomalacia - the most common cause of stridor in infants and children due to floppiness of the upper structures of the larynx. The diagnosis is made by flexible laryngoscopy in the doctor's office.
- Subglottic stenosis - the larynx narrowed below the vocal cords. Children with subglottic stenosis are usually not diagnosed at birth, but, more often, a few months after, particularly if the child's airway becomes swollen by a cold. Cough and recurrent croup are common symptoms. The child usually outgrows the problem. The diagnosis is made by bronchoscopy.
- Subglottic hemangioma - a mass of tiny blood vessels. Subglottic hemangiomas grow in the child's first few months of life. Symptoms first occur around the age of 3 to 6 months. The natural course of these masses is to shrink over time. Even so, medical or surgical treatment is often necessary to relieve symptoms of airway obstruction.
- Tracheomalacia - part of the trachea may be too soft. The child will usually outgrow this condition. It causes stridor or wheezing (during expiration - like asthma). Broncoscopy is required to confirm the diagnosis.
- Vascular rings - the trachea may be compressed or encircled by a blood vessel causing tracheomalacia and wheezing.
Infectious causes
- Croup - an infection caused by a virus that leads to swelling in the airways and causes breathing problems. Cough and stridor are typical symptoms.
- Bronchitis - an inflammation of the breathing tubes (airways), called bronchi, which causes increased production of mucus and other changes. Acute bronchitis is usually caused by infectious agents such as bacteria or viruses. It may also be caused by physical or chemical agents - dusts, allergens, strong fumes - and those from chemical cleaning compounds, or tobacco smoke.
- Severe tonsillitis - Tonsils are small, round pieces of tissue that are located at the sides of the back of the throat. The tonsils can usually be seen in the throat of your child by using a light. Tonsillitis is defined as inflammation of the tonsils from infection, causing a sore throat.
- Abscess in the throat - an infection surrounded by inflamed tissue. The throat is very sore and swollen. If the abscess is large enough, it may narrow the airway to a critically small opening.
The diagnosis
Stridor is usually diagnosed on the medical history and physical examination of your child. It is important to remember that stridor is a symptom of some underlying problem or condition. If your child has stridor, your child's physician may order some of the following tests to help determine the cause of the stridor:
- Chest x-ray
- Flexible laryngoscopy - done in the office in about 15 seconds; usually gives the correct diagnosis
- Bronchoscopy - a procedure done under anesthesia to examine the entire airway from the nose and throat, the larynx, trachea and bronchi in the lungs.
Treatment
Specific treatment of stridor will be determined by your child's physician based on:
- Your child's age, overall health, and medical history
- Cause of the condition
- Extent of the condition
- Your child's tolerance for specific medications, procedures, or therapies
- Expectations for the course of the condition
- Your opinion or preference
Treatment may include:
- Surgery
- Medications by mouth or injection (to help decrease the swelling in the airways)
Hospitalization and emergency surgery may be necessary depending on the severity of the stridor.