What causes chronic sore throat?

Chronic Sore Throat: Causes and Diagnostic Approach

The most common causes of chronic sore throat are chronic tonsillopharyngitis, gastroesophageal reflux disease (GERD), and laryngopharyngeal reflux disease, followed by submandibular sialadenitis, with less common causes including allergy, systemic comorbidities, and psychiatric illness. 1

Primary Etiologies

Most Common Causes

• Chronic tonsillopharyngitis is the leading cause of chronic sore throat, often presenting without the acute features of bacterial infection 1
• Gastroesophageal reflux disease (GERD) is the second most common cause, and can present as "silent GERD" without typical heartburn or regurgitation symptoms in up to 75% of cases 2
• Laryngopharyngeal reflux disease represents a distinct entity where refluxate irritates the upper respiratory tract, particularly the larynx, without aspiration 2, 1
• Submandibular sialadenitis is another major cause that should be considered in the differential 1

Infectious Causes

• Viral pharyngitis accounts for 65-85% of acute sore throat cases, with common pathogens including rhinovirus, coronavirus, adenovirus, influenza, parainfluenza, and Epstein-Barr virus 3
• Group A β-hemolytic streptococcus (Streptococcus pyogenes) is the primary bacterial cause, accounting for 15-30% in children and 5-15% in adults 4, 3
• Candidal infection should raise suspicion for HIV infection in the appropriate clinical context 5
• Mycoplasma pneumoniae and Chlamydia pneumoniae may present with associated atypical pneumonia 5

Systemic and Other Causes

• Systemic comorbidities including diabetes mellitus, hypothyroidism, uremia, and arthritides can manifest as chronic sore throat 1
• Allergy is a significant contributor to chronic throat symptoms 1
• Psychiatric illnesses can present with chronic sore throat as a somatic complaint 1
• Thyroid disease, particularly thyroiditis, can cause chronic sore throat through local irritative effects of the inflamed thyroid 2
• Oral submucous fibrosis, stylalgia, tuberculosis, recurrent aphthous ulcers, and dietary deficiencies represent other important causes 1

Diagnostic Approach

Initial Evaluation

• Duration assessment is critical—chronic sore throat is defined as symptoms persisting >12 weeks despite conventional medication 1
• Associated symptoms help narrow the differential: conjunctivitis, cough, hoarseness, coryza, or diarrhea suggest viral etiology 3
• Smoking and alcohol history should be obtained, as approximately 39% of chronic sore throat patients are chronic smokers and 31% use alcohol 1
• HIV testing should be considered, particularly in patients with candidal infection or other risk factors 1

Physical Examination Findings

• Tonsillar exudates, fever, tender anterior cervical adenopathy, and absence of cough suggest bacterial pharyngitis 4, 3
• Laryngoscopy may reveal signs of reflux laryngitis including posterior laryngitis with red arytenoids and piled-up interarytenoid mucosa 2
• Generalized lymphadenopathy and splenomegaly suggest infectious mononucleosis 3
• Scarlatiniform rash indicates Streptococcus pyogenes or Corynebacterium haemolyticum infection 5

Life-Threatening Complications to Exclude

• Peritonsillar abscess, parapharyngeal abscess, epiglottitis, and Lemierre syndrome must be excluded in patients with severe presentations, difficulty swallowing, drooling, neck tenderness or swelling, or airway obstruction 4, 3

Common Pitfalls

• Do not assume typical GI symptoms are required for GERD-related chronic sore throat—up to 75% of cases present without heartburn or regurgitation 2
• Do not rely on cough character or timing to distinguish between etiologies, as these features are not diagnostically useful 2
• Do not overlook systemic diseases such as thyroid disorders, diabetes, or autoimmune conditions that can manifest primarily as chronic sore throat 2, 1
• Female patients have slightly higher prevalence (female:male ratio 1.25), which should inform clinical suspicion 1