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Strep Throat

En Español (Spanish Version)

Definition | Causes | Risk Factors | Symptoms | Diagnosis | Treatment | Prevention


Strep throat is a type throat infection that causes a sore throat. Although the term is commonly used, very few sore throats are strep throat.

Sore Throat Due to Inflammation

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Strep throat is caused by specific bacteria. The bacteria enter through inhaled air droplets and grow in the throat causing the infection and symptoms.

The strep bacteria is spread by airborne droplets, most often from coughs or sneezes of infected people or touching a contaminated surface then touching your eyes, nose, or mouth.

Risk Factors

Strep throat is more common in children and adolescents. Other factors that increase your chance of strep throat include:

  • Exposure to family member or friend who has strep throat
  • Crowded living situations
  • Having strep living in the throat—occurs in 15% to 30% of people


Strep throat may cause:

  • Red, sore throat with white patches
  • Headache
  • Swollen, sore glands in the neck
  • Fever
  • Red spots on the roof of the mouth
  • Painful, difficult swallowing
  • Chills
  • Fatigue
  • Nausea and possibly vomiting
  • Decreased appetite
  • Rash
  • Muscle aches, especially in the neck, and abdominal pains, especially in younger children
  • Swelling in back of mouth

Complications of untreated strep throat can be serious and include:

Post-streptococcal glomerulonephritis is also rare, but it can occur, even with treatment


Your doctor will ask about your symptoms and medical history. A physical exam will be done. Tests to confirm strep throat may be used and include:

  • Rapid antigen strep screen—Antigens are a part of the body's immune response to specific infection. This test can identify antigens within a few minutes of the test. However, a negative test does not mean you do not have strep throat, the body may not have had enough time to make antigens yet.
  • Throat culture—A sample of throat fluid is taken to a lab to see if strep bacteria grows. It takes a few days to gets results.
  • Rapid DNA test—DNA technology is used to detect strep throat. This test is as accurate as throat culture. The results are usually available in one day.

Only a rapid DNA test or throat culture can confidently distinguish strep throat from throat infections caused by other things. Doctors will often make a diagnosis and decide about treatment based on symptoms, physical findings, and test results.


Most sore throats, including strep throat, will get better on its own in 7-10 days. Although the sore throat disappears, the infection may remain. It is important to follow through with proper treatment to prevent serious complications.


Your doctor will prescribe antibiotics to treat the infection. Antibiotics may be given as a pill or a shot. Symptoms will often fade in the first few days of medication, but it is important to take all of the antibiotics as prescribed.

Your doctor may advise over-the-counter pain relievers and fever reducers to ease symptoms.


: Aspirin is not recommended for children with a current or recent viral infection. Check with your doctor before giving your child aspirin.


To reduce your chances of getting strep throat:

  • Wash your hands carefully.
  • Don't share beverages or food.
  • Avoid exposure to other people who may have a strep infection.
  • Replace your toothbrush after starting antibiotic treatment to prevent re-infecting yourself.

If you have recurrent strep infections in your family, check to see if someone is a carrier. Strep carriers have the infection in their throat, but do not get sick. It is possible to treat the carrier to prevent the infection from making others sick.





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  • Sore throats. American Academy of Otolaryngology–Head and Neck Surgery website. Available at: Accessed September 29, 2014.
  • Strep throat. Mayo Clinic website. Available at: Accessed November 10, 2007.
  • Streptococcal pharyngitis. DynaMed website. Available at: Updated March 18, 2014. Accessed September 29, 2014.

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