Symptoms of strep throat go away within three to seven days both with and without antibiotic treatment, according to WebMD. However, without treatment, a person is contagious for up three weeks following the infection, risking serious complications.
When antibiotics are administered, a person is no longer contagious after 24 hours of treatment, even when symptoms remain, according to WebMD. Complications of strep throat include the formation of an abscess and rheumatic fever. Treating strep throat using antibiotics minimizes the risk of developing these more serious complications. Strep throat symptoms typically begin two to five days after exposure to someone ill with a strep infection.