Laryngitis

Laryngitis is an inflammation of the larynx that may manifest in acute or chronic forms. Acute laryngitis is commonly caused by viral infection of the nasopharynx that descends into the larynx or by severe damage to the vocal cords due to smoking or vocal strain. The primary symptoms are hoarseness (loss of voice) and a dry cough. Acute laryngitis may progress to chronic laryngitis if symptoms persists for more than three weeks. Direct or indirect visualization of the vocal cords and glottis (inflamed, hyperemic mucosa with edema and possibly exudates) is usually sufficient to diagnose the condition. Laboratory tests including complete blood count (CBC) and culture swabs should be carried out, particularly in chronic cases. Voice rest and cessation of smoking are the most important measures for treating the condition.

• Acute laryngitis: inflammation of the vocal fold mucosa and larynx for < 3 weeks
• Chronic laryngitis: inflammation of the vocal fold mucosa and larynx for > 3 weeks

References:^[1]

• Acute
  • Infection
    • Viral infections from the nasopharynx (most common cause)
    • Bacterial infections: usually secondary to preexisting viral laryngitis
  • Environmental
    • Vocal strain
    • Inhalation of airborne irritants
  • Rarely, systemic diseases like Granulomatosis with polyangiitis, rheumatoid arthritis, and sarcoidosis
• Chronic
  • Gastroesophageal reflux disease (GERD): most common cause
  • Smoking
  • Recurring upper respiratory infection (URTI)

• Hoarseness/loss of voice
• Dry cough (barking cough may occur in severe cases)
• Fever, dysphagia, and lymph node enlargement in cases of severe infection
• Accessory respiratory muscle use in case of narrowed airway
• Inspiratory stridor is common in children
• Symptoms of the underlying disease (e.g., retrosternal pain in GERD, frontal headaches in sinusitis, etc.)

• Acute types specific to children
  • Acute laryngitis of the subglottic structures
    • Laryngotracheitis (croup)
    • Laryngeal diphtheria
  • Acute laryngitis of the supraglottic structures: epiglottitis ^[2]
  • See also “Differential diagnoses of pediatric inspiratory stridor.”
• Acute membranous laryngitis

Diagnosis of both forms of laryngitis is primarily based on clinical history, examination findings, and laryngoscopy.

Laryngoscopy ^[3]

Laryngoscopy helps visualize the vocal cords and the supraglottic structures (glottis, arytenoids, aryepiglottic folds). Either of the following types of laryngoscopy can be implemented to establish a diagnosis.

• Types
  • Indirect: can be performed during a routine physical examination
    • Does not allow for as much visualization as direct laryngoscopy
    • Caution is needed in suspected cases of acute epiglottitis, as it can trigger a laryngeal spasm, especially in children. ^[4]
  • Direct: allows for detailed examination of the larynx, including vocal fold movement
    • Flexible endoscope (in patients who are awake)
    • Rigid laryngoscope (in patients under general anesthesia)
    • Can be used to obtain tissue for biopsy, cultures, and smears (to identify the presence of organisms)
• Findings
  • Acute laryngitis
    • Erythema and small dilated vasculature on the inflamed vocal folds
    • Vocal fold movement is maintained, but aperiodic and closure is incomplete.
  • Chronic laryngitis
    • Mucus (especially in the posterior wall of the larynx), erythema, and edema are the most common findings → lead to minimal movement
    • Pus associated with bacterial infection
    • Vocal cord atrophy
    • Cobblestoning of mucosa in laryngopharyngeal reflux/GERD associated laryngitis

The following modalities are used to treat both acute and chronic laryngitis:

• Vocal rest (voice rest)
• Cessation of smoking
• Speech therapy
• Steam inhalation
• Antibiotics are given only in cases of bacterial superinfection.