Scarlet fever is a contagious childhood infection caused by streptococcus bacteria. It occurs most often in children between the ages of 2 and 10.
Basically, scarlet fever is strep throat with a rash produced by the bacteria.
Scarlet fever can have serious complications if it goes untreated. It can lead to abscesses on the tonsils or, rarely, rheumatic fever, which may develop two to three weeks after the rash appears.
The good news is that prompt treatment for scarlet fever usually results in full recovery.