Pharyngitis: Causes and Symptoms

• Pharyngitis, commonly known as a sore throat, is the inflammation of the pharynx
• The pharynx is located in the back of the throat, between the tonsils and the voice box (larynx)

Causes

• Viral infections are the most common cause of pharyngitis, accounting for approximately 40-60% of cases
• Common viral causes include:
  • Rhinovirus (common cold)
  • Influenza virus (flu)
  • Adenovirus
  • Epstein-Barr virus (EBV, causing mononucleosis)
  • Coronavirus
  • Herpes simplex virus (HSV)
• Bacterial infections account for a smaller percentage of pharyngitis cases, around 5-15% in adults and 15-30% in children
• The most common bacterial cause is Streptococcus pyogenes (group A Streptococcus, GAS), which causes strep throat
• Less common bacterial causes include:
  • Streptococcus dysgalactiae
  • Arcanobacterium haemolyticum
  • Neisseria gonorrhoeae
  • Chlamydia pneumoniae
  • Mycoplasma pneumoniae
• Fungal infections can cause pharyngitis, but are relatively rare, and mostly occur in immunocompromised individuals or those using inhaled corticosteroids
• Candida species are the most common fungal cause
• Other causes of pharyngitis include:
  • Allergies
  • Irritants (such as smoke, pollution, or chemicals)
  • Trauma
  • Tumors

Symptoms

• Common symptoms of pharyngitis include:
  • Sore throat
  • Pain when swallowing (odynophagia)
  • Redness in the throat
• Other symptoms may include:
  • Fever
  • Cough
  • Runny nose
  • Headache
  • Hoarseness
  • Swollen lymph nodes in the neck
  • White patches on the tonsils (in some cases, especially with bacterial infections)
  • Body aches
  • Fatigue
• Symptoms can vary depending on the cause of the pharyngitis
• Viral pharyngitis often presents with milder symptoms, such as a runny nose and cough, in addition to a sore throat
• Strep throat typically presents with a more sudden onset of sore throat, fever, and pain when swallowing
• Symptoms of strep throat typically do not include a cough or runny nose
• Mononucleosis pharyngitis may be associated with significant fatigue, swollen lymph nodes in the neck, and enlargement of the spleen

Diagnosis

• Diagnosis is typically based on a physical examination and medical history
• During the physical exam, the doctor will look at the throat for redness, swelling, and white patches
• The doctor may also palpate the lymph nodes in the neck to check for swelling
• A throat swab may be performed to test for bacterial infections, particularly Streptococcus pyogenes
• Rapid antigen detection tests (RADT) can provide quick results for strep throat, typically within minutes
• A throat culture is more accurate than RADT, but takes longer to process (24-48 hours)
• If mononucleosis is suspected, a blood test (Monospot test) may be performed to detect the presence of antibodies to the Epstein-Barr virus (EBV)

Treatment

• Treatment depends on the cause of the pharyngitis
• Viral pharyngitis typically resolves on its own within a week
• Treatment for viral pharyngitis is mainly supportive and aims to relieve symptoms
• Supportive treatments include:
  • Rest
  • Drinking plenty of fluids
  • Using a humidifier
  • Gargling with warm salt water
• Over-the-counter pain relievers, such as acetaminophen or ibuprofen, can help reduce fever and pain
• Lozenges and throat sprays can also provide temporary relief from sore throat
• Bacterial pharyngitis, such as strep throat, is treated with antibiotics
• Penicillin or amoxicillin are commonly prescribed antibiotics for strep throat
• For patients who are allergic to penicillin, alternative antibiotics such as azithromycin or cephalexin may be used
• It is important to complete the full course of antibiotics to prevent complications, such as rheumatic fever
• Treatment for fungal pharyngitis involves antifungal medications
• Nystatin is a common antifungal mouthwash used to treat oral thrush
• In more severe cases, oral antifungal medications such as fluconazole may be prescribed

Complications

• Complications from pharyngitis are rare, but can occur, especially with untreated bacterial infections
• Possible complications of strep throat include:
  • Rheumatic fever
  • Glomerulonephritis
  • Peritonsillar abscess
  • Otitis media
  • Sinusitis
• Rheumatic fever is a serious inflammatory condition that can affect the heart, joints, brain, and skin
• Glomerulonephritis is a kidney disease
• Peritonsillar abscess is a collection of pus behind the tonsils
• Early diagnosis and treatment of bacterial pharyngitis with antibiotics can help prevent these complications

Prevention

• Good hygiene practices can help prevent the spread of pharyngitis
• Ways to prevent spread:
  • Washing hands frequently with soap and water
  • Avoiding close contact with people who are sick
  • Not sharing utensils, cups, or other personal items
  • Covering the mouth and nose when coughing or sneezing
• Annual influenza vaccination can help prevent pharyngitis caused by the influenza virus