Scarlet fever is an infection that can happen with strep throat. It is caused by the same bacteria that cause strep throat. Scarlet fever is most common in children between the ages of 5 and 15, but it can affect people of any age. Scarlet fever is rare in children younger than 3 years and adults.

Scarlet fever causes a rough, red rash along with symptoms of strep throat, which include a fever, a sore throat, and swollen lymph nodes. The rash usually appears one or two days after the fever starts. The rash starts on the neck, underarm, and groin area and then spreads to the rest of the body. The rash usually fades in about a week. Then the skin may start to peel.

Scarlet fever and strep infections are treated with antibiotics. Treatment can prevent serious problems from a strep infection.