Laryngitis

Laryngitis means inflammation of the larynx. Laryngitis which persists beyond three weeks is defined as chronic.^1,2

• Acute laryngitis is commonly due to infection, but there are many rarer causes. The basic pathophysiology is inflammation of the mucosa lining the vocal folds and larynx. If infection is involved, white cells aggregate to remove infectious material from the area. Oedema of the laryngeal lining increases the amount of pressure required to produce sound, resulting in dysphonia or aphonia. Changes to the structure of the larynx may also result in a lower register of speech.
• Chronic laryngitis is usually due to environmental, toxic or mechanical factors.³ The term implies irreversible changes to the laryngeal mucosa. The ciliary tree is usually damaged, mainly on the posterior wall, with resultant pooling of mucus and the production of a reactive cough. Mucous across the vocal cords may result in laryngeal spasm. Depending on the cause there may be hyperaemia, oedema, inflammation and various changes to the morphology of the laryngeal mucosal cells.

Accurate figures regarding acute laryngitis are not available as the condition often goes unreported. However, the Birmingham Research Unit of the Royal College of General Practitioners reported a peak average incidence of 23 per 100,000 patients (all ages) per week over the period 1999-2005.⁴Chronic laryngitis is a complex condition which is similarly under-reported and often goes unrecognised. One series reported an average age at presentation of 45 years and an equal incidence of men and women. There is a 2:1 incidence of men versus women, although the differential is thought to be decreasing due to the increase in women smoking. The typical presenting patient is an adult, in the sixth decade of life.

Symptoms

Acute laryngitis

• Hoarseness
• Symptoms of upper respiratory tract infection (cough, rhinitis, fever)
• Odynophonia (pain on speaking), dysphagia, odynophagia (pain on swallowing)
• Dyspnoea
• Fatigue and malaise

Chronic laryngitis

By definition, any patient with symptoms of acute laryngitis persisting for longer than three weeks should be deemed to have chronic laryngitis. In such patients, the following additional information should be sought:

• Personal history:
  • Duration of symptoms, any relieving or aggravating factors
  • Symptoms suggestive of ill health - lung cancer, thyroid disease
  • Occupational history, especially exposure to irritant substances or temperature change
  • Voice abuse
  • Symptoms suggestive of gastro-oesophageal reflux disease (GORD) - e.g. heartburn, chest pain, otalgia, cough, wheezing, globus, throat clearing⁶
  • History of asthma - this can sometimes be confused with vocal cord dysfunction, history is of throat rather than chest discomfort often with additional atypical symptoms (voice difficulty, laryngeal stridor, wheeze worse in inspiration)
  • History of allergy
  • Immunocompromised patients - consider candidal involvement
• Medication history:
  • Medications causing local drying, mucosal injury - antihistamines, decongestants, diuretics, antihypertensives, psychotropic drugs, inhaled steroids (don't forget to ask about over the counter medicines)
  • Drugs increasing the tendency to develop GORD by decreasing the tone of the lower oesophageal sphincter - calcium channel blockers, nitrates, beta-blockers, progesterone
  • Immunosuppressant therapy - consider candida
  • Inhalation treatments - thermal baths
• Surgical history:
  • HIstory of intubation - recurrent laryngeal damage particularly likely in thoracic and abdominal surgery
  • Surgery leading to anatomic alterations predisposing to GORD (again, thoracic and abdominal)
• Neck trauma
• Ingestion of caustic substances
• Travel history (for the possibility of parasitic infections)
• Family history
  • Autoimmune diseases (e.g. amyloidosis, systemic lupus erythematosus, Wegener granulomatosis, rheumatoid arthritis)
  • Similar condition in other family members - consider exposure to environmental pollutants
  • Contagious disease - e.g. tuberculosis
• Social history
  • Smoking, recreational abuse, alcohol intake
  • LIfestyle increasing the risk of infectious disease (e.g. sexually unsafe practices, history of syphilis)
  • Diet - consumption of foods likely to lower oesophageal tone and increase likelihood of GORD (e.g. chocolate, caffeine)

Examination

Unless the clinician is experienced in the technique of indirect laryngoscopy (indirect examination of the larynx , using a laryngeal mirror) examination in the limited context of primary care is generally unhelpful, other than to exclude other conditions such as pharyngitis. Patients whose symptoms persist for more than three weeks should have indirect laryngoscopy.

Acute laryngitis

• Infection:
  • Rhinoviruses
  • Parainfluenza viruses
  • Respiratory syncytial virus
  • Adenoviruses
  • Influenza viruses
  • Measles virus
  • Mumps virus
  • Bordetella pertussis
  • Varicella-zoster virus
• Any cause of chronic pharyngitis

Chronic laryngitis

In addition to the factors outlined above (see History), the following should be considered:

• Infection:
  • Bacterial - Staphylococcus aureus (commonest), followed by Haemophilus influenzae and pneumococcal species.
  • Tuberculosis
  • Leprosy
  • Syphilis- usually occurs in the second and third stages
  • Rhinoscleroma - caused by the gram-negative rod Klebsiella rhinoscleromatis
  • Actinomycosis
  • Viruses- play a minor role
  • Fungal infections - common. especially in immunocompromised patients, patients taking inhaled steroids
  • Blastomycosis and histoplasmosis
  • Leishmaniasis and sporotrichosis
• Lymphoma of the larynx

Acute laryngitis

• Early chronic laryngitis
• Reflux laryngitis
• Spasmodic dysphonia

Chronic laryngitis

• Chondronecrosis of the larynx
• Contact granulomas
• Glottic stenosis
• Iatrogenic vocal fold scar
• Subglottic stenosis in adults
• Sulcus vocalis
• Vascular lesions of the vocal fold
• Vocal fold cysts

Acute laryngitis¹

• Investigations are rarely helpful in primary care. A swab for microbiological analysis may be contributory if excessive exudate is present.
• Clinicians with the skill to perform indirect laryngoscopy will typically find redness and small dilated vasculature on the inflamed vocal folds.

Chronic laryngitis^2,7

• Laboratory Tests:
  • Full blood count with differential to exclude infection
  • Sputum culture for bacteria, fungi and viruses
  • Laryngeal mucosal swab for microbiological analysis
  • Serology for autoimmune markers
  • Tests for syphilis and tuberculosis if clinically indicated
• Radiology:
  • Lateral Xray of neck - may show supraglottic or retropharyngeal swelling, or soft tissue density in subglottic airway
  • Chest radiograph
  • CT scanning and MRI may be appropriate if detailed morphology of the larynx required
  • Barium swallow study, double-contrast upper GI series, and manometry - may be required to exclude GORD
  • Videostrobe - unit consists of stroboscopic unit (light source and microphone), a video camera, an endoscope, and a video recorder, useful in diagnosing vocal cysts, polyps and nodules⁸

Acute laryngitis

• Measles
• Mumps
• Chickenpox
• Herpes simplex virus⁹

Chronic laryngitis

• GORD
• Infections - viral, bacterial, fungal, mycoplasma
• Autoimmune disease

Acute laryngitis¹

• Most cases are mild and self-limiting.
• Non-drug measures found to be helpful include inhaling humidified air and minimal use of the voice.
• Inhaling humidified air promotes moisture of the upper airway, helping to clear secretions and exudate.
• Use of antihistamines and corticosteroids is not supported by evidence. Indeed these treatments may cause temporary respite leading to overuse of the voice, as well as drying of the larynx.
• Antibiotics have a limited place in the initial management of acute laryngitis. A Cochrane review found no difference in clinical outcome in adult patients given Penicillin V compared to placebo. Erythromycin promoted some benefit in terms of voice improvement, but this was not thought to be clinically signficant.¹⁰
• Antibiotics may be helpful in patients who have persistent symptoms or who have other problems such as immune system deficiency.
• Acute laryngitis is unusual in children under the age of 18. Failure to respond to symptomatic relief should raise the possibility of other conditions, such as tracheobronchitis, especially if there are other features such as dyspnoea.

Chronic laryngitis²

• Supportive measures - these include hydration (approximately 2 litres per day), steam inhalation, avoidance of pollutants and cigarette smoke, and avoidance or limitation of exposure to environmental or occupational sensitisers.
• Treat the underlying condition - e.g. GORD may need appropriate lifestyle advice, prokinetic drugs and proton pump inhibitors.
• Hospital admission - be prepared to arrange hospital admission if the patient develops stridor, becomes systemically unwell, or is at risk of food aspiration.
• Surgery - this may be contributory in the relief of laryngeal stenosis, and the treatment of GORD.

• Acute laryngitis - complications are rare, as the disease is usually self-limiting. Damage to the vocal cords is possible in patients who try to over-compensate for the dysphonia.
• Chronic laryngitis - The main complications are voice loss, airways obstruction and chronic cough. Spread of infection to surrounding tissues and laryngeal stenosis can occur with prolonged disease. An association with laryngeal carcinoma remains unproven.

In acute laryngitis, the prognosis is usually excellent.¹With chronic laryngitis the prognosis depends on the underlying condition.²

There are no particular preventive measures for acute laryngitis, although avoidance of irritant factors such as cigarette smoke may be helpful.¹
In chronic laryngitis:²

• Irritant factors should be avoided - especially active or passive smoking.
• Patients on inhaled steroids should be advised regarding appropriate use - e.g. dose reduction, twice-daily dosing, mouth rinsing and use of spacers.
• Speech therapy may be necessary in cases of voice abuse.
• Lifestyle advice should be given to patients at risk of GORD.