Hoarseness in children: Evaluation

INTRODUCTION — "Hoarseness," or "dysphonia," is the term used to describe a change in the quality of the voice. The voice quality can be breathy, strained, fatigued, rough, tremulous, or weak. It may have a change in pitch or abnormal resonance. Hoarseness can be caused by any process that affects the structure or function of the larynx (table 1).

The evaluation of the child with hoarseness will be presented here. The etiology and management are discussed separately. (See "Common causes of hoarseness in children".)

ANATOMY

Larynx — The larynx is part of the anterior hypopharynx. In newborns, the larynx is situated at the level of C3-C4, where it facilitates simultaneous respiration and swallowing during infant feeding. It gradually descends to the level of C6-C7 by the age of 15 years. The mobile, crescent-shaped hyoid bone forms the anterior upper limit of the larynx, which is divided into three regions relative to the level of the vocal cords:

●The supraglottic region encompasses the area above the vocal folds and includes the epiglottis, arytenoids, aryepiglottic folds, and false vocal folds.

●The glottic region includes the vocal folds and the region immediately below the vocal folds. This region has the narrowest diameter in adults.

●The subglottic region refers to the region starting 1 cm below the vocal folds and ending in the upper cervical trachea. This region corresponds to the cricoid cartilage and has the narrowest diameter in infants and children.

The larynx is formed by the articulation of the thyroid and cricoid cartilages (figure 1). The ring-shaped cricoid cartilage is the only cartilage that completely encircles the airway. The epiglottis and the anterior commissure of the vocal folds are attached to the inner aspect of the thyroid cartilage at the thyroid prominence (also called the Adam's apple).

The arytenoids, which help to position and move the vocal folds, articulate on the posterior edges of the cricoid cartilage (figure 2). The aryepiglottic folds are formed by mucosa that runs from each edge of the epiglottis to the arytenoid. The lower portion of the aryepiglottic fold creates the false vocal folds (also called the false vocal cords or vestibular folds), which are protective in normal phonation function (figure 1).

The true vocal folds (the vocal cords) are comprised of the thyroarytenoid muscle and the vocal ligament and extend from the vocal process of the arytenoid to the inner surface of the thyroid cartilage anteriorly. The vocal folds undergo age-related changes, lengthening as the child grows.

The muscles of the larynx (figure 2) act to open and close the glottis and to regulate voice quality (table 2).

Nerve supply — The superior and recurrent laryngeal branches of the vagus nerve innervate the laryngopharynx. The recurrent laryngeal nerves (RLNs) branch from the vagus in the upper chest and reenter the neck ("recur") in the thoracic inlet, extending to the larynx superiorly, traveling in or near the tracheoesophageal groove. The right and left RLNs travel underneath the right subclavian artery and around the arch of the aorta, respectively. The superior laryngeal nerve descends along the pharynx and divides into internal and external branches.

The superior laryngeal nerve supplies sensory innervation to the epiglottis and false vocal folds and the motor innervation to the cricothyroid muscle. The remainder of the larynx receives motor and sensory innervation from the RLN. The interarytenoid muscle is the only muscle that is dually innervated by both RLN.

PHYSIOLOGY — The larynx has three main functions: phonation, airway protection, and cough production.

Phonation — Phonation occurs as a result of the interaction between the true vocal cords and the exhaled column of air from the lungs, which creates oscillation of the vocal fold mucosa relative to the deeper vocal fold structures (thyroarytenoid muscle and vocal ligament).

The intrinsic laryngeal musculature adjusts the tension and location of the vocal folds to produce fine changes in voice production (table 2). Changes in pitch and frequency are mediated by the tension and position of the vocal folds, which are controlled by the cricothyroid and thyroarytenoid muscles. Contraction of the thyroarytenoid shortens and contraction of the cricothyroid muscle lengthens the vocal fold, resulting in lower and higher pitch, respectively.

Voice is articulated through fine motor control of the tongue and lips and resonated by the airway above the vocal folds. The size of the pharynx, oral cavity, nasal cavity, and larynx increase with age, resulting in changes of resonance, particularly in boys. The loudness of voice is directly related to subglottic pressure.

Airway protection — The airway is protected from ingested material during swallowing by laryngeal elevation, epiglottic deflection, and closure of the false and true vocal folds. Contraction of the paired lateral cricoarytenoid and the interarytenoid muscles results in adduction of the vocal folds and closure of the airway. Contraction of the posterior cricoarytenoid muscle causes rotation of the arytenoid and opening of the airway.

Cough — Transient glottic closure causes increased intrathoracic pressure that results in cough. Rapid glottic opening during cough facilitates the expectoration of tracheal air and mucous.

CAUSES — Hoarseness can be caused by any process that affects the structure or function of the larynx. Etiologic categories include infection, inflammation, trauma, obstruction or infiltration, and congenital anomalies (table 1). In children, hoarseness is most often due to a benign or self-limited cause (eg, viral upper respiratory infection or vocal abuse and misuse). Hoarseness is a common complaint in children, with reported prevalence rates ranging from 4 to 23 percent [1-3]. Common causes of hoarseness in children are discussed in greater detail separately. (See "Common causes of hoarseness in children".)

EVALUATION

Overview — The initial evaluation of the child with hoarseness includes a complete history and physical examination. Additional information can be obtained from laryngoscopy and formal voice evaluation [4]. Radiologic studies are not usually necessary. Children who have rapidly progressive symptoms, stridor, aspiration, pain, or respiratory distress may require urgent otolaryngology evaluation. (See 'Specialist evaluation' below.)

In most cases, the cause can easily be identified through the history and physical examination, including laryngoscopy.

History — The history focuses on characterizing the type of voice complaint, its onset, and associated symptoms:

●Type of voice complaint – The first step is to determine in what way the child's voice has changed. Descriptions from the child, parent, or teacher are helpful. The type of voice complaint can help to pinpoint the location of the voice problem [5]:

•Breathiness – Breathiness of the voice, due to leakage of air through the vocal cords, may indicate vocal fold paralysis or a lesion preventing complete closure of the glottis

•Change in resonance – A change in resonance (eg, a hypernasal or hyponasal quality (movie 1 and movie 2)) may indicate a mass lesion, nasal obstruction, or incomplete palatal closure

•Change in pitch – A change in pitch or quality of the voice may indicate a mucosal irregularity of the vocal fold

•Soft voice – Difficulty with loudness may indicate a pulmonary or effort-related problem

●Timing of onset – It is important to determine whether the onset of dysphonia was acute, gradual, or longstanding; whether it was related to a particular event (eg, surgery, illness); whether the symptoms are intermittent or constant; and whether they are static or progressive. Acute problems are more commonly related to vocal abuse and result from injury to the mucosa overlying the vocal folds. Acute problems may also be caused by an infectious or inflammatory process [6]. Chronic, progressive problems typically indicate a structural abnormality.

●Associated symptoms – It is important to ask if there are any associated symptoms such as stridor, wheezing, coughing, respiratory distress, nasal obstruction, rhinorrhea, postnasal drip, change in olfaction, ear pain, sore throat, dysphagia, odynophagia, feeding difficulties, aspiration, or weight loss. Children with associated stridor, aspiration, pain, or respiratory distress may warrant urgent referral to an otolaryngologist (see 'Criteria for referral' below). In addition, the clinician should ask if there are factors that alleviate or aggravate the dysphonia (eg, allergies, environmental exposures, vocal overuse, upper respiratory tract infection) or if the hoarseness is worse at a particular time of day (morning versus evening). Hoarseness that worsens over the course of the day may suggest vocal abuse.

●Past medical history – If the voice problem had onset in infancy, details of the birth history should be reviewed, including whether forceps were used in the delivery and whether the quality of the newborn cry was normal. Other aspects of the past medical history that may be pertinent include any surgeries or hospitalizations (particularly if they required intubation); any trauma or surgery involving the heart, chest, base of the skull, or neck; and any history previous voice problems, speech or language delay, developmental delay, behavioral problems, psychiatric disorders, hearing loss, or chronic ear disease. In addition, the child's medications should be reviewed (both prescribed and over the counter). Medications that may contribute to hoarseness include inhaled glucocorticoids, antihistamines, and anticholinergics.

Physical examination — A complete head and neck examination should be performed during the initial visit. Otoscopic examination, including pneumatic otoscopy, should be performed to rule out middle ear pathology (see "The pediatric physical examination: HEENT", section on 'Otoscopic examination').

Other pertinent components of the physical examination include:

●Examination of the skin for hemangiomas, lymphatic malformations, or other lesions

●Examination of the nose for patency, obstructing lesions, foreign body, or evidence of allergy (see "Chronic rhinosinusitis: Clinical manifestations, pathophysiology, and diagnosis")

●Examination of the oral cavity for mass lesions, mucosal abnormalities, tonsil size, and motor function of the palate and tongue

●Palpation of the neck for mass lesions

Radiologic evaluation — Radiologic evaluation of children with hoarseness is not usually necessary. This is because most causes of childhood hoarseness involve the mucosal surface of the vocal folds or a functional problem of the larynx. (See "Common causes of hoarseness in children".)

Radiologic evaluation can be helpful in the following situations:

●Suspected mass lesion – In a child with vocal fold paralysis suspected to be caused by a mass lesion either within the larynx or along the course of the recurrent laryngeal nerve (RLN), imaging with a chest radiograph, computed tomography (CT), or magnetic resonance imaging (MRI) may be useful. However, if the child's primary complaint is hoarseness, CT or MRI should generally not be performed without first directly visualizing the larynx [4]. (See 'Flexible laryngoscopy' below.)

●Suspected foreign body – If there is clinical concern for aspiration of a foreign body, chest radiography or fluoroscopy may be helpful. The diagnosis of foreign body aspiration is easily established with plain radiographs when the object is radiopaque (image 1); however, most objects aspirated by children are radiolucent (eg, nuts, food particles) and are not detected with standard radiographs unless aspiration is accompanied by airway obstruction and air trapping. Evaluation of suspected foreign body aspiration is discussed in greater detail separately.(See "Airway foreign bodies in children".)

●Suspected aspiration – If there is clinical concern for aspiration (eg, from a vocal fold paralysis or laryngeal cleft), a modified barium swallow may be helpful. Evaluation of suspected aspiration is discussed in greater detail separately. (See "Aspiration due to swallowing dysfunction in children", section on 'Evaluation'.)

●Suspected paradoxical vocal fold motion – Airway imaging with fluoroscopy or high-resolution CT can sometimes be helpful in the evaluation of patients with suspected paradoxical vocal fold motion (mostly to exclude other causes of airway obstruction) [7,8]. However, in most cases, flexible laryngoscopy is sufficient to make the diagnosis and additional imaging studies are not necessary (see 'Flexible laryngoscopy' below). The diagnosis of paradoxical vocal fold motion is discussed in greater detail separately. (See "Inducible laryngeal obstruction (paradoxical vocal fold motion)".)

●Atypical croup – The diagnosis of acute laryngotracheitis (croup) is generally made clinically, and radiographic confirmation of subglottic narrowing is not required in the vast majority of cases. However, radiographic evaluation with chest and/or airway radiographs (image 2) may be warranted if the course is atypical (eg, recurrent or prolonged symptoms or failure to respond as expected to therapeutic interventions). The evaluation and diagnosis of croup are discussed in greater detail separately. (See "Croup: Clinical features, evaluation, and diagnosis", section on 'Evaluation'.)

SPECIALIST EVALUATION

Otolaryngology

Criteria for referral — Evaluation by an otolaryngologist is warranted for children with any of the following (the timing depends on the severity of symptoms):

●Urgent referral to an otolaryngologist:

•Rapidly progressive symptoms

•Stridor

•Aspiration

•Pain

•Respiratory distress

●Routine referral to an otolaryngologist and/or speech language pathologist:

•Hoarseness lasting longer than two weeks

•Unexplained hoarseness (eg, not associated with an upper respiratory tract infection)

•Progressive hoarseness

•Socially unacceptable hoarseness

Flexible laryngoscopy — The complete evaluation of a child who has hoarseness and any of the above indications includes visualization of the larynx by flexible (indirect) laryngoscopy [9]. Flexible fiberoptic nasopharyngolaryngoscopy is a valuable tool in the examination of the larynx in children [10]. After adequate anesthesia of the nasal cavity, the flexible scope is used to examine the nasopharynx and larynx, including:

●Closure of the palate and adenoid pad in the nasopharynx

●Architecture of the base of the tongue

●Abnormalities in the pyriform sinuses (eg, pooling of secretions, mass lesion)

●Architecture and function of the larynx, assessing for any abnormalities (eg, mass lesion, cleft)

●Symmetry of the vocal folds

●Any lesions or other abnormalities on vocal folds

●Patency of the airway and completeness of airway closure

●Laryngeal mobility during speech and swallowing

●Evidence of reflux

The older child is asked to perform a variety of tasks under direct visualization:

●Voicing the letter "i" permits visualization of vocal fold adduction

●Deep inspiration or a "sniff" permits visualization of abduction

●Pronouncing "i" with a low pitch upscale to a high pitch permits testing of the cricothyroid muscle

●Fluency of speech is determined by repeating phrases and connected speech; this demonstrates normal neurologic control of vocal fold movement

Stroboscopy — The stroboscopic examination is another useful diagnostic tool in the evaluation of hoarseness. During phonation, the vocal folds vibrate more than 100 times per second. The stroboscope sends out bright flashes of light that are timed to the frequency of vocal fold vibration, a process that visually "freezes" the image for the observer and permits evaluation of the mucosal edges of the vocal folds for irregularity or subtle changes. The endoscopes used for stroboscopy are usually a rigid telescope with a 90° prism (which allows visualization of the larynx through the oral cavity) and the flexible endoscope. Stroboscopic examination is usually well tolerated in children older than six to seven years [11].

Direct laryngoscopy — Direct laryngoscopy may be necessary if the larynx is not adequately visualized by nasopharyngolaryngoscopy or stroboscopic examination, if the child's hoarseness is not responding to therapy, or if a suspicious lesion is detected by the above examinations. Direct laryngoscopy is performed in the operating room. The laryngoscope is placed within the oral cavity to directly visualize the larynx. A microscope or telescope can be used to enhance visualization. Complications of direct laryngoscopy are rare and may include dislocation of the jaw, inadvertent removal of teeth, discomfort, small mucosal tears, injury to the larynx, and risk of anesthesia.

Evaluation by other specialists

Speech and language — Involvement of a speech-language pathologist is crucial in the diagnosis and treatment of a child with hoarseness. The speech-language pathologist performs an acoustic assessment including pitch, loudness, voice quality, and phonation time. Glottic airflow, subglottic air pressure, and glottic resistance are evaluated during aerodynamic assessment. (See "Evaluation and treatment of speech and language disorders in children".)

Hearing evaluation — Hearing evaluation should be performed if there are any concerns for hearing loss or language delay. (See "Hearing loss in children: Screening and evaluation".)

SUMMARY AND RECOMMENDATIONS

●Dysphonia – "Dysphonia" or "hoarseness” is the term used to describe a change in the quality of the voice. The voice quality can be breathy, strained, fatigued, rough, tremulous, or weak. It may have a change in pitch or abnormal resonance. (See 'Introduction' above.)

●Causes – Hoarseness can be caused by any process that affects the structure or function of the larynx (figure 1). Etiologic categories include infection, inflammation, trauma, obstruction or infiltration, and congenital anomalies (table 1). In children, hoarseness is most often due to a benign or self-limited cause (eg, viral upper respiratory infection or vocal abuse and misuse). Common causes of hoarseness in children are discussed in greater detail separately. (See "Common causes of hoarseness in children".)

●Initial evaluation – An initial evaluation of a child with hoarseness includes (see 'Evaluation' above):

•History – The history focuses on characterizing the type of voice complaint, its onset, and associated symptoms. (See 'History' above.)

•Physical examination – A complete head and neck examination should be performed, including the oral cavity and nose and otoscopic examinations and palpation of the neck for mass lesions. In addition, the skin should be examined for hemangiomas, lymphatic malformations, or other lesions. (See 'Physical examination' above.)

•Imaging – Radiologic evaluation is usually not necessary but may be helpful in specific circumstances (eg, suspected mass lesion, foreign body, aspiration). (See 'Radiologic evaluation' above.)

●Indications for referral – Referral is warranted for children with any of the following (the timing depends on the severity of symptoms) (see 'Criteria for referral' above):

•Urgent referral to an otolaryngologist – Rapidly progressive symptoms, stridor, aspiration, pain, or respiratory distress

•Routine referral to an otolaryngologist and/or a speech language pathologist – Hoarseness lasting longer than two weeks, unexplained hoarseness (eg, not associated with an upper respiratory tract infection), progressive hoarseness, or socially unacceptable hoarseness