Scarlet fever is a relatively rare infection. It affects people who have a throat or skin infection caused by certain strains of the group A streptococcus bacteria.

What is going on in the body?

Scarlet fever usually occurs after a throat infection with Streptococcus bacteria, such as strep throat. However, it may also occur after a strep infection of the skin, soft tissues, uterus, or a surgical wound. The bacteria that cause scarlet fever make a toxin that results in a skin rash. The rash usually spreads over most of the body, only to peel off a week later. Scarlet fever is now uncommon because of the regular use of antibiotics for strep infections.

What are the causes and risks of the infection?

Scarlet fever is caused by an infection with a strain of strep bacteria that makes the scarlet fever toxin. Strep throat is usually spread person to person through coughing or sneezing. Strep skin infections are usually caused by contact with infected skin.

Those at highest risk for scarlet fever are as follows: