Hoarseness

Synonym: dysphonia

Hoarseness is a subjective term and usually refers to a weak or altered voice. Dysphonia is similar but may also mean difficulty making sounds. Some terms which may be used to describe a voice change are: breathy, harsh, tremulous, weak, reduced to a whisper, or vocal fatigue (voice deteriorates with use)¹.

NB: any patient aged 45 and over with persistent unexplained hoarseness requires investigation to exclude malignancy (see 'Investigation and referral' section, below).

The first part of this article discusses hoarseness as a presenting symptom. The second part covers some common laryngeal conditions causing hoarseness.

Airway emergencies and hoarseness

Epidemiology

A retrospective analysis of data from a large American claims database found that of almost 55 million individuals, 536,943 patients (ages 0 to >65 years) were given a dysphonia diagnosis (point prevalence rate of 0.98%)³.

One study screening hoarseness in children aged 6-10 years reported a prevalence of 12.0% (7.8% of girls, 15.8% of boys)⁴.

Risk factors for voice problems⁵

• Smoking (also the main risk factor for laryngeal carcinoma).

• Excess alcohol consumption.

• Gastro-oesophageal reflux.

• Professional voice use - eg, teachers, actors and singers.

• Environment: poor acoustics, atmospheric irritants and low humidity.

• Type 2 diabetes (neuropathy, poor glycaemic control)⁶.

Anatomy and physiology⁷

Sound is produced in the larynx by vibration of the vocal cords. Resonance occurs in the pharynx, nose and mouth; articulation uses the mouth and tongue. Coughing requires adduction of the vocal cords to be effective.

Innervation of the laryngeal muscles is from the vagus nerve via its branches, the superior laryngeal and recurrent laryngeal nerves. The recurrent laryngeal nerve controls abduction and adduction of the vocal cords. This nerve has a long course, from the base of the skull to the mediastinum: on the left side it loops under the aortic arch and on the right under the subclavian artery.

The vocal cords are subject to high forces and so are vulnerable to voice overuse or misuse.

Aetiology⁵⁸

Voice problems are often multifactorial and due to voice overuse. Serious pathology must be excluded (see 'Investigation and referral' section, below).

Causes of hoarseness

Functional dysphonia

• Where no organic cause is found - a diagnosis of exclusion.

• A common cause of hoarseness⁹. There are various forms (below).

Infections

• Acute laryngitis (common), often with upper respiratory infection. Usually viral (may have secondary infection with staphylococci or streptococci).

• Other infections - fungal or tuberculous.

Benign laryngeal conditions
For details see last section 'Some specific voice disorders and their management'.

• Voice overuse - common.

• Benign lesions of the vocal cords - eg, nodules (singer's nodes), polyps and papillomas.

Malignancy

• Laryngeal cancer - smoking is major risk factor.

• Other neck or chest tumours - eg, lung cancer, lymphoma, thyroid cancer.

Neurological

• Laryngeal nerve palsy (see 'Some specific voice disorders and their management', below): this has various causes, including lung cancer, other tumours and thoracic aortic aneurysm.

• Stroke and other focal brain lesions.

• Parkinson's disease - voice change can be a presenting feature¹⁰.

• Motor neurone disease.

• Essential tremor.

• Myasthenia gravis.

Systemic

• Endocrine: hypothyroidism, acromegaly.

• Rheumatoid arthritis affecting the cricoarytenoid joints¹¹.

• Granulomatous disease - eg, sarcoidosis, tuberculosis, syphilis, granulomatosis with polyangiitis.

• Autoimmune disorders can affect the larynx¹⁰.

Causes in children⁵

• Congenital - eg, laryngeal web, laryngomalacia, congenital cyst.

• Older children: vocal cord nodules, voice overuse, gastro-oesophageal reflux, papillomas (as for adults).

• Very rarely, malignancy.

Other causes

• Various rare causes of hoarseness, from case reports, are described by Ulis¹⁰.

Contributing factors

• Drying of the laryngeal mucosa - from low humidity, nasal obstruction, smoking, and air pollution, or from medication (eg, antihistamines, inhaled steroids and anticholinergics).

• Upper respiratory tract infection.

• Voice overuse (see 'Some specific voice disorders and their management', below).

• Gastro-oesophageal reflux (reflux laryngitis or laryngopharyngeal reflux).

• Scarring - eg, after prolonged intubation.

• Age-related loss of pliability (normal ageing of the voice).
  

Assessment¹²¹³

History

• Symptoms - duration, onset and pattern of symptoms; check the patient's meaning of 'hoarseness'.

• Precipitating factors - recent upper respiratory tract infection, change in voice use - eg, shouting or singing..

• Occupation, normal pattern of voice use, impact of voice problem on the patient's life.

• Other ENT symptoms - dysphagia, aspiration, throat or ear pain, nasal blockage.

• Smoking, alcohol.

• Reflux symptoms - eg, acid taste in the mouth in the morning, throat clearing, cough or 'choking' sensation, sensation of a lump in the throat¹⁴.

• Past medical history, particularly chest disease, thyroid surgery, neck trauma, and neurological symptoms.

Examination in primary care¹⁵

• Signs of airway obstruction - see 'Emergency' under 'Management', above.

• Laryngeal function - listen to the patient's voice and assess cough and swallowing.

• Examine the neck - scars, lymph nodes, thyroid gland. Localised tenderness suggests infection or abscess.

• Any signs of underlying cause - eg, fever, hypothyroidism, tremor, weight loss.

• Chest or neurological examination may be appropriate.

ENT assessment¹²

• Inspection of the larynx - by indirect laryngoscopy and/or fibreoptic nasendoscopy.

• Voice quality can be evaluated using the GRBAS (= Grade (severity), Roughness, Breathy voice, Asthenia (weakness) and Strain) assessment.

• The Reflux Symptom Index can be used to identify likely gastro-oesophageal reflux.

Investigation and referral⁵

Initial investigations

Further investigations

These depend on the clinical picture:

• Consider investigations for systemic causes where appropriate - eg, thyroid function.

• Fibreoptic laryngoscopy - does not require general anaesthetic, so enables examination of the larynx while using the voice⁸.

• Stroboscopy (videolaryngostroboscopy) uses fibreoptic images in slow motion to provide pictures of the working larynx¹⁷.

• Voice pathologists use various other techniques to measure aspects of voice production, such as amplitude, pitch, range and aerodynamic efficiency.

Management¹²

Management depends on the specific cause but voice therapy and other non-surgical management are the first-line treatment for most benign lesions of the larynx.

Non-surgical management

• Voice hygiene advice:

  • Adequate hydration.

  • Avoidance of vocal strain (shouting, throat clearing, excessive voice use).

  • Smoking cessation, alcohol reduction (both are irritants and alcohol is dehydrating).

  • Reduction in caffeine intake.

• Treat gastro-oesophageal reflux (if suspected):
  

  • Dietary advice.

  • Liquid alginate suspension has been found to be effective in small studies but further research is needed. The addition of proton pump inhibitors was found in one study to have no additional beneficial effect¹⁸.

• Voice therapy:
  

  • Teaches techniques to maximise vocal effectiveness.

  • Is effective for both organic pathology (eg, nodules and polyps) and non-organic causes (eg, muscle tension dysphonia).

• Referral to a specialist voice clinic:
  

  • Is appropriate if the larynx appears normal and there is no improvement with initial voice therapy. Provides detailed voice assessment and specialist investigations such as videostroboscopy.

• Other therapies:
  

  • Relaxation techniques and counselling may be helpful where psychological factors are contributing.

  • 'Mental imagery' and 'laryngeal shaking' treatments were used in one uncontrolled trial on patients where no organic cause had been found, with good reported outcomes¹⁰¹⁹.

Surgical management

• Laryngeal papillomas require surgery first-line.

• Persistent nodules and polyps may require surgery.

• There are various surgical techniques used to treat vocal cord paralysis.

• Voice therapy is often used as a adjunct to surgery.

Some specific voice disorders and their management

Laryngeal nerve palsy or vocal cord paralysis

This may cause a 'breathy' voice, an inefficient cough or airway narrowing. The clinical features depend on whether one or both cords are affected and the position of the cords - whether abducted or adducted. 'Semon's law' suggests that an incomplete paralysis of the recurrent laryngeal nerve affects the abductor muscles first, so that the vocal cord is in the midline. Complete paralysis affects the adductor muscles also, so the cord is fixed midway, in the paramedian position. Electromyography, however, has shown that the situation is far more complex. There is usually some activity, even if there is no detectable movement on laryngoscopy²⁰.

Surgical techniques such as Teflon® injection or implants, combined with voice therapy, can restore function²¹.

Benign lesions of the vocal cords

• Vocal cord nodules (nodes or singer's nodes). These are epithelial thickenings of the vocal cord, similar to calluses; they are often due to voice overuse. Voice therapy is the main treatment; surgery is occasionally needed²².

• Polyps of the vocal folds. These are unilateral (unlike nodules which are normally bilateral). They may need excision to exclude malignancy²².

• Papillomas of the larynx¹². These are lesions caused by the human papillomavirus (HPV). If untreated and large, they may cause airway obstruction. Invasive carcinoma can occur (rarely). They are usually treated surgically. Intralesional antiviral therapy (cidofovir) may be used for recurrent papillomas.

• Reinke's oedema. This is oedema of the vocal folds, which tends to give a deep, hoarse voice. It is usually linked to smoking plus voice overuse²³. Smoking cessation and voice therapy may help; surgery has also been used¹².

Voice overuse or misuse²⁴

This is a common problem in some occupations such as acting and teaching; it may also follow unaccustomed voice use, such as shouting at a football match. Vocal strain may be exacerbated when attempting to compensate for an acute respiratory infection.

Benign lesions such as nodules ('singer's nodules'), cysts, haemorrhages and varices can occur with voice overuse.

Management involves:

• Excluding other pathology.

• An accurate diagnosis (see investigation details above) - fibreoptic laryngoscopy and stroboscopic techniques are useful.

• A specific programme tailored to the observed pathology can then be devised. Prescribing rest alone may not be effective.

• Persistent nodules can be excised.

Functional dysphonia²⁵

This is a diagnosis of exclusion, where there is neither a structural abnormality of the larynx nor cord paralysis. There are various types of functional dysphonia. Symptoms include vocal fatigue (voice becoming worse with use) and laryngeal discomfort. There may be various interacting causes, such as heavy demands on the voice, poor vocal technique and stress.

Voice therapy is the main treatment. Other treatments used include relaxation techniques, biofeedback and other methods such as mental imagery and laryngeal shaking or laryngeal massage¹⁹.

Spasmodic dysphonia

This is classified as focal laryngeal dystonia. It is characterised by involuntary endolaryngeal constriction during phonation. The cause is unknown but is thought to involve the central nervous system. Symptoms are breaks in the voice or voice tremor. There are two types - adductor and abductor spasmodic dysphonia. 85% are of the adductor type. The gold standard treatment for adductor spasmodic dysphonia is botulinum toxin injection but this requires repeated injections. A comparative trial suggests that surgery in the form of laser thyroarytenoid myomectomy may be a more popular option with patients²⁶.

Prevention

Prevention measures include:

• 'Vocal hygiene' measures (see under 'Non-surgical management', above)²⁷.

• Recognising early warning signs of voice problems, such as an unintentional change in pitch, voice fatigue (the voice gets weaker with increasing use) and sore throat not due to infection²⁸.

• Biofeedback is sometimes a useful prophylactic measure for high-risk populations (eg, call centre agents)²⁹.