Strep throat should be diagnosed as quickly as possible because of the serious complications that can develop if left untreated. These include rheumatic
fever, which can
damage the heart, and acute nephritis, which can
damage the kidneys; both can be fatal.
The onset of strep throat is characterised by sudden high fever and a severe sore throat.
The bacterium responsible for scarlet fever, a strep-related illness, can also cause pharyngitis.