Sore throat

Sore throat (Pharyngitis/Tonsillitis): Causes and mechanisms

Sore throat is an extremely common symptom that arises from inflammation of the mucous membrane of the throat (pharyngitis) or the palatine tonsils (tonsillitis, or angina). The pain can be sharp, stabbing, "burning," and significantly worsens when swallowing. In the overwhelming majority of cases (85-95%) the cause is viral infections, which do not require antibiotic treatment. However, it is important to be able to suspect bacterial tonsillitis, which requires specific therapy.

Viral vs. Bacterial causes: What’s the difference?

• Viral infections (most common cause):
  • Pathogens: Rhinoviruses, adenoviruses, influenza virus, Epstein-Barr virus (in infectious mononucleosis).
  • Clinical picture: Sore throat is usually one of the symptoms of an upper respiratory infection and is accompanied by runny nose, cough, general malaise. The throat is red, but usually without exudates.
• Bacterial infections:
  • Pathogen: Most commonly beta-hemolytic group A streptococcus (GAS).
  • Clinical picture (streptococcal tonsillitis): Sudden onset, severe pain when swallowing, high fever, absence of cough and runny nose. Tonsils are bright red, swollen, often with white‑yellow purulent exudates.

Non-infectious causes of sore throat

Sometimes sore throat is not related to an infection. Possible causes include:

• Post-nasal drip: Dripping mucus from the nose down the back of the throat irritates it.
• Gastroesophageal reflux (GERD): Backflow of acidic stomach contents into the throat, especially at night.
• Dry air, mouth breathing, vocal strain.

Diagnosis of streptococcal tonsillitis is performed using a rapid test or throat culture, as described in more detail in the article "Fever with sore throat in children".