Overview of Sore Throat

Sore throat, also called pharyngitis, is the inflammation of the pharynx (throat). The throat extends from the nasal passages above and behind the mouth to the esophagus (tube that carries food to the stomach) in the neck. Sore throat occurs most commonly with a viral upper respiratory infection (URI).

It is also symptomatic of a number of diseases, including:

  • diphtheria,
  • mononucleosis caused by Epstein-Barr virus,
  • gonorrhea, and
  • acute HIV infection.

Incidence and Prevalence of Sore Throat

Approximately 40 to 60 percent of cases of sore throat are caused by a virus and about 15 percent are associated with Streptococcus infection (strep throat). In the United States, children typically average five sore throats per year and Streptococcus infection every 4 years. Adults typically experience two sore throats per year and Streptococcus infection approximately every 8 years.

The incidence worldwide is higher, possibly because of resistance to antibiotics caused by overprescription. Sore throat is more prevalent in winter, when respiratory disease incidence is highest. The incidence of pharyngitis and strep throat is highest in children between the ages of 5 and 18. Sore throat is rare in children younger than 3 years old.

Causes and Risk Factors for Sore Throat

Viral upper respiratory tract infection that produces postnasal drip, such as the common cold, and seasonal allergies are the most common causes of sore throat. Organisms such as Streptococcus, Mycoplasma pneumoniae, Chlamydia pneumoniae, and Neisseria gonorrhoeae cause bacterial pharyngitis. Infection is spread by person-to-person contact.

Risk factors include the following:

  • Coughing
  • Inhaling pollutants (e.g., household cleaners, automobile exhaust)
  • Other illnesses (e.g., diphtheria, mononeucleosis)
  • Seasonal allergies
  • Smoking and second-hand smoke

People with seasonal allergies to pollen often experience sore throat as a result of postnasal drip.

Sore Throat Signs and Symptoms

Swallowing may be difficult or painful and the throat may feel scratchy. The throat often appears red, swollen, or puffy, and may have white spots of purulent exudate (pus). Fever and cough are also common. Examination may reveal swollen tonsils (near the base of the tongue), which may also be covered with white or gray exudate. The lymph nodes in the neck often become swollen and tender.

Sore Throat Complications

Complications such as rheumatic fever (inflammation of connective tissue and joint pain), scarlet fever (fever with body rash), tonsil abscess, and glomerulonephritis (kidney disease) can result from untreated streptococcal infection. Severe pharyngitis associated with Corynebacterium diphtheriae and infectious mononucleosis can obstruct the airway and cause lower respiratory problems (e.g., pneumonia).

Longstanding infection of the tonsils (tonsillitis) can result in peritonsillar abscess, which affects the connective tissue of the tonsil.

Sore Throat Diagnosis

Diagnosis is made by examining the throat, observing its appearance, and feeling the neck for swollen lymph nodes. Because viral and bacterial pharyngitis can look the same, a throat culture is often used to determine if bacteria is present. The throat is swabbed with cotton and the sample is sent to a laboratory for culture and analysis. It takes more than 24 hours to obtain results. A rapid strep test may be performed and analyzed in the physician's office; results are available in about 15 minutes. This test is not as reliable and negative results must be confirmed by culture.

Treatment for Sore Throat

Sore throat related to viral URI usually resolves without medication. Gargling with warm salt-water and taking acetaminophen (Tylenol) may relieve pain and reduce swelling. Bacterial pharyngitis is treated with antibiotics.

If the tonsils have been chronically infected, they may need to be removed surgically (tonsillectomy).

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 02 Jun 2000

Last Modified: 11 Aug 2014