Also sometimes called scarlatina, scarlet fever is an infectious disease caused by a type of streptococcus bacteria. The bacteria are spread in airborne droplets. Symptoms of the disease typically develop within about a week of infection. They may include a scarlet rash that starts on the neck and upper body and spreads rapidly, sore throat, fever, headache, swollen glands in the neck, and vomiting.
Sometimes, a white coating develops on the tongue; this coating peels off after a few days, leaving the tongue red and swollen (strawberry tongue).
Scarlet fever is treated with antibiotics to clear up the infection, and pain relievers to relieve symptoms. Most people recover within about a week.