Pharyngitis – streptococcal; Streptococcal pharyngitis
Definition of Strep throat
Strep throat is caused by Group A bacteria. It is the most common bacterial infection of the throat.
Causes, incidence, and risk factors
Strep throat is most common in children between the ages of 5 and 15, although it can happen in younger children and adults. Children younger than 3 can get strep infections, but these usually don’t affect the throat.
Strep throat may be very mild, with only a few symptoms, or it may be severe. Often, persons with strep throat get sick 2 to 5 days after they are exposed to the bacteria that causes the illness.
Signs and tests
A rapid test can be done in most health care provider offices, but misses a few of the cases. A throat swab can be tested (cultured) to see if strep grows from it. However, it will take one to two days for results to come back.
Be aware that most sore throats are caused by viruses, not strep. Sore throats should only be treated with antibiotics if the strep test is positive. Strep cannot be accurately diagnosed by symptoms or a physical exam alone.
The probable outcome is good. Nearly all symptoms resolve in one week. Treatment prevents serious complications associated with streptococcal infections.
Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. – 1/10/2010