Scarlet fever is a disease caused by an infection with bacteria in the group A Streptococcus (the same bacteria that cause strep throat).
Scarlet fever was once a very serious childhood disease, but now it is easy to treat. The streptococcal bacteria that cause it produce a toxin that leads to the hallmark red rash of the illness.
The main risk factor for getting scarlet fever is infection with the bacteria that cause strep throat. A history of strep throat or scarlet fever in the community, neighborhood, or school may increase the risk of infection.
The time between infection and symptoms is short, generally 1 - 2 days. The illness typically begins with a fever and sore throat.
The rash usually first appears on the neck and chest, then spreads over the body. People say it feels like sandpaper. The texture of the rash is more important than the appearance to confirm the diagnosis. The rash can last for more than a week. As the rash fades, the skin around the fingertips, toes, and groin area may peel.
Other symptoms include:
- Abdominal pain
- Bright red color in the creases of the underarm and groin
- General discomfort (malaise)
- Muscle aches
- Sore throat
- Swollen, red tongue (strawberry tongue)
Exams and Tests
- Physical examination
- Throat culture that shows bacteria from group A Streptococcus
- Rapid antigen detection (throat swab)
Antibiotics are used to kill the bacteria that cause the throat infection. This is crucial to prevent rheumatic fever, a serious complication of strep throat and scarlet fever.
With proper antibiotic treatment, the symptoms of scarlet fever should get better quickly. However, the rash can last for up to 2 to 3 weeks before it fully goes away.
Complications are rare with the right treatment, but can include:
When to Contact a Medical Professional
Call your health care provider if:
Bacteria are spread by direct contact with infected people, or by droplets exhaled by an infected person. Avoid contact with infected people.
Alvro R, Borkan JM, Ferri FF. Scarlet fever. In: Alvero R, Borkan JM, Ferri FF, et al., eds. Ferri's Clinical Advisor. 1st ed. Philadelphia, PA: Elsevier Mosby; 2014.
Bisno AL, Stevens DL. Streptococcus pyogenes. In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2009:chap 198.
Gerber MA. Group A Streptococcus. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 176.