Streptococcal Infections – Infections – Merck Manual Consumer Version

Strep throat can resolve within 1 to 2 weeks, even without treatment. However, early diagnosis and treatment are still recommended to prevent rheumatic fever and associated heart disease.

Antibiotics shorten the duration of symptoms in young children but have only a modest effect on symptoms in adolescents and adults. Nevertheless, antibiotics are given to help prevent the spread of the infection to the middle ear, sinuses, and mastoid bone, as well as to prevent spread to other people. Antibiotic therapy also helps prevent rheumatic fever, although it may not prevent kidney inflammation (glomerulonephritis). Usually, antibiotics do not need to be started immediately. Waiting 1 to 2 days for culture results before starting antibiotics does not increase the risk of rheumatic fever. An exception is when a family member has or has had rheumatic fever. Then, every streptococcal infection in any family member should be treated as soon as possible.

Usually, penicillin or amoxicillin is given by mouth for 10 days. One injection of a long-lasting penicillin (benzathine) can be given instead. People who cannot take penicillin can be given erythromycin, clarithromycin, or clindamycin by mouth for 10 days or azithromycin for 5 days.