Strep throat is an infection in the throat caused by bacteria.
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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. This occurs with coughing or sneezing from infected people, or by 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
- Swollen, sore glands in the neck
- Red spots on the roof of the mouth
- Painful, difficult swallowing
- Nausea and possibly vomiting
- Decreased appetite
- 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:
- Middle ear infection or sinus infection
- Peritonsillar abscess
- Bacterial meningitis
- Infective endocarditis
- Rarely, rheumatic fever and pediatric autoimmune neuropsychiatric disorders (PANDAS) associated with streptococcal infection
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 (this is called a false negative).
- 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. The results are usually available in one day.
Only a rapid DNA test or throat culture can confidently distinguish strep throat from throat infections with other causes. 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.
Note: Aspirin is not recommended for children with a current or recent viral infection. Check with your doctor before giving your child aspirin.
To help reduce your chance 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.
American Academy of Otolaryngology—Head and Neck Surgery
Family Doctor—American Academy of Family Physicians
About Kids Health—The Hospital for Sick Children
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Last reviewed September 2016 by David Horn, MD, FACP Last Updated: 8/10/2015