Stridor is the name given to a high pitched squeaking or whistling sound that is heard when the airway gets obstructed. It is commonly a symptom of an underlying illness. It is seen most commonly in children and rarely so in adults. The reason behind this is that children have narrow airways when compared to adults and thus are more vulnerable to blocked airways. In some instances, children develop Stridor due to congenital abnormalities. In such cases, Stridor can be noted with a few days of birth of the child.[2]
It is necessary to treat severe cases of Stridor promptly to prevent the airways from getting completely blocked. If this happens, then the child will have severe problems breathing which may result in respiratory failure. It is well known that gasses such as oxygen exert equal pressure in all directions. However, if a gas moves in a forward direction then there will be more pressure exerted in the direction where the gas is flowing and there will be less pressure exerted on the lateral sides.[1]
What happens when air passes through a narrow tube such as the airway of a child, due to the principle explained above the pressure, which keeps the airways open, drops significantly due to forward motion of oxygen gas. This results in the airways getting too close to each other or even close or block. This obstruction is what produces the whistling sound of a Stridor.[1] The article below highlights some of the common causes of Stridor in Children and ways to manage the condition.
What Causes Stridor In Children?
Some of the common causes of Stridor in Children include:
- Croup: it is quite a common medical condition seen in children that causes inflammation of the larynx and the vocal cords. This usually occurs as a result of a viral infection. It is seen mostly in children between the ages of 6 months to 6 years and it is the boys who tend to get it more than girls. The primary presenting features of Croup along with an audible Stridor include a barking cough and a hoarse voice. The child will also have problems with breathing [2]. Generally, this condition does not require any specific treatment. However, if the child has breathing problems then a consultation with a physician is required for medication management.[2]
- Foreign Objects: It is quite common for small children to inhale foreign objects, some of which then clog the airways causing a stridor. The presenting symptoms for this include problems with breathing, wheezing, dysphagia, pain in the throat and chest, excessive drooling, and poor eating. To identify the foreign object an x-ray will have to be conducted for its location. If the foreign object is sharp or dangerous then a surgical procedure may be required to remove the object.[2]
- Laryngomalacia: This is a pathological condition in which the tissue of the larynx becomes soft. This makes them get into the airways and blocking them causing a Stridor. This is a congenital condition and the symptoms can be observed by the time the child is one month in age. This is a benign condition and most of the children outgrow this problem. Apart from audible stridor when breathing in, the child will have problems with feeding, acid reflux, bluish tinge to the skin, and lack of adequate weight gain.[2]
- Vocal Cord Paralysis: This is a condition that develops when there is either unilateral or bilateral movement loss of the vocal cords. Injury or infection is the primary cause of this condition. In some cases, vocal cord paralysis can be visualized at the time of the birth of the child [2]. The primary presenting features of vocal cord paralysis include a weak tone of voice and choking or coughing when being fed. A surgery may be required to treat the condition if it persists for a period of two years and only one vocal cord is involved. For children with bilateral vocal cord paralysis a breathing tube might be put in till the time the paralysis improves.[2]
- Subglottic Stenosis: This is a pathological condition in which there is narrowing of the airways. This happens mainly as a result of scarring of the area. In some cases, this narrowing os present right from the time of birth of the child. This is termed as congenital subglottic stenosis. In other cases, this can develop as a result of prolonged breathing tube use. This is termed as acquired subglottic stenosis.[2] The primary symptoms of this condition are severe barking cough and breathing problems along with audible stridor. Mild cases of this condition do not require any treatment but severe cases may at times require surgery.[2]
- Vocal Cord Lesions: There are basically two types of lesions seen in the vocal cords, namely vocal cord nodules and vocal cord papillomas. While the former prevents the vocal cords from closing properly the latter are caused due to the HPV virus. In some cases, nodules may develop after prolonged screaming or shouting, or even severe bout of coughing.[2] Other than audible stridor, children with vocal cord lesions will have problems with breathing, exercising, have a distinct change in voice, and problems with eating. While vocal cord lesions caused by nodules do not require treatment, those caused by the HPV virus will require surgical treatment. In most cases, close observation is recommended for cases of vocal cord lesions and medications are given to control the other symptoms.[2]
How is Stridor In Children Treated?
The treatment for stridor involves identifying the causative factor and then formulating a treatment plan accordingly. After getting to the bottom of the cause, the physician might recommend medications either oral or in the form of injections to reduce the airway swelling and open them up. In cases of blockages, surgery may have to be done to open up the blocked airways. If the airway is stenosed or small then again surgery will have to be done to expand the airways for normal flow of air.[2]
With regard to the prognosis, stridor normally is a symptom of an underlying medical illness. Thus identifying the cause is the primary marker for the prognosis of the patient. In some cases, if the treatment is delayed then it may affect the prognosis. However, in majority of the cases the causes of a stridor are fairly benign and can be cured with proper treatment.[2]
