Definition of Scarlet fever:

Scarlet fever is a disease caused by infection with the group A Streptococcus bacteria (the same bacteria that causes strep throat).

Causes, incidence, and risk factors:

Scarlet fever was once a very serious childhood disease, but now is easily treatable. It is caused by the streptococcal bacteria, which produce a toxin that leads to the hallmark red rash of the illness.

The main risk factor is infection with the bacteria that causes strep throat. A history of strep throat or scarlet fever in the community, neighborhood, or school may increase the risk of infection.