Infection: Scarlet Fever

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Infection: Scarlet Fever

Causes and Symptoms
The Future
For more information


Scarlet fever is an infectious disease caused by certain strains of the bacteria (Group A streptococcus) that cause strep throat. It is characterized by a high fever, a red rash with a sandpapery texture that covers most of the body, and a so-called strawberry tongue.


Scarlet fever is an infectious disease of childhood that can occur together with strep throat. It is spread by fluids from the throat or nose of an infected person or by contact with a drinking glass, soiled tissue, or other object touched by an infected person. The incubation period is short; children can feel sick within twelve hours of being infected, although the usual incubation period is one to two days. Children are contagious from the moment the acute symptoms appear until the rash completely fades.

The first phase of scarlet fever is a prodrome, or warning period marked by a general feeling of tiredness, headache, sore throat, and fever. In the acute phase of scarlet fever, which begins about two days after the child first feels sick, the characteristic rash appears, first on the neck and then spreading downward to the rest of the body. The child often has flushed or reddened cheeks with the area around the mouth unusually

pale. The rash begins to fade in about three or four days, followed by the peeling of the skin on the face, palms of the hands, and fingers.

Scarlet fever tends to be a milder disease than it was before the use of antibiotics to treat it in the 1950s. It can, however, lead to rheumatic fever, inflammation of the kidneys, or certain types of psychiatric disorders (grouped together as PANDAS disorders) if it is not promptly treated.


Scarlet fever is most likely to affect children between the ages of five and fifteen years; it is unusual in people over eighteen. It affects boys and girls equally, and appears to be equally common in all races and ethnic groups. In the United States it is most likely to occur in winter and spring.

Scarlet fever is thought to occur in 1 percent of the school-age population, or about 10 percent of children diagnosed with strep throat.

Causes and Symptoms

Scarlet fever is caused by a Group A streptococcus that normally lives in the upper respiratory tract. In many cases the disease follows an episode of strep throat. As the bacteria grow in the tissues of the nose and throat, they secrete a toxin that is responsible for the rash associated with scarlet fever.

During the prodrome, the child may have a fever between 101 and 104°F (38.3°C and 40°C), along with:

  • Sore throat
  • Headache
  • Vomiting
  • Abdominal cramps
  • Enlarged glands in the neck that are sore to the touch
  • Aching muscles

The World's Fastest Woman

Scarlet fever is rarely considered a serious threat children's health, but in the 1940s it was still a common cause of disabilities, including complications affecting the joints and muscles. Wilma Rudolph (1940–1994), the first American woman to win three gold medals in track and field in a single Olympic Games, could not even walk without braces until she was twelve years old. Rudolph suffered from polio and pneumonia as well as scarlet fever in her early years. She was treated at home by her mother; the future champion later remembered that during her youth, “mother used to have all these home remedies she would make herself, and I lived on them.”

After starting high school, Rudolph became a basketball star and earned a position on the U.S. women's track and field team for the 1956 Olympics. She was only sixteen years old at the time. In 1960 she won three gold medals at the Rome Olympics, running the 100-meter dash in only eleven seconds and being hailed as “the fastest woman in history.” In 1963 Rudolph completed her college education at Tennessee State University and became an elementary school teacher.

Rudolph did not forget her early struggles with illness and the importance of her mother's

encouragement. In 1981 she started a foundation to help other young athletes by teaching them that success is possible even in the face of sickness and other difficulties. Her foundation provides free coaching in the young people's chosen sports. She died of brain and throat cancer in 1994, but her work lives on in the accomplishments of the athletes she has inspired and helped.

When the rash appears, it is sometimes described as looking like a bad sunburn. The sandpapery texture of the rash is its most important feature. It may itch and will typically turn white when pressed with a finger. Other symptoms of this phase of the illness include:

  • Chills.
  • Fast heartbeat.
  • Small pinpoint spots on the inside of the mouth caused by tiny broken blood vessels. These are sometimes called Forchheimer spots.
  • Appearance of the tongue changes from a whitish-looking coating over red and swollen taste buds to a completely red and swollen tongue.
  • Appearance of Pastia's lines. These are lines of bright red color that appear in the folds of the body—the armpits, elbows, neck, knees, and groin area.
  • Peeling of the rash about four or five days after its appearance.
  • White or yellowish patches on the tonsils.


The diagnosis of scarlet fever is usually based on a combination of the patient's history—particularly recent exposure to other children with strep throat or scarlet fever—and the doctor's examination of the patient's throat, neck glands, and skin. The doctor may also take a sample of fluid from the child's throat on a cotton swab. The fluid can be sent to a laboratory for a throat culture, which is an accurate test that takes two days. The doctor may also perform what is called a rapid strep test. It can detect the streptococci in a few minutes in the doctor's office. The rapid strep test, however, is not as accurate as a throat culture.

A newer test for scarlet fever is called a rapid DNA test, which is as accurate as a throat culture but takes less than a day to give results.


Patients with scarlet fever are treated with a course of antibiotics, most commonly penicillin or a similar drug known to be effective in treating strep throat. The child will usually not be contagious within a day or two of starting treatment and can return to school once the fever goes down. It is important, however, for the child to take the full course of antibiotics (usually ten days), even though he or she may start to feel better in a few days. Peeling of the skin may continue for another two or three weeks, but it does not mean that the child is still contagious.

The doctor may recommend a soft or liquid diet if the child's throat is very sore and he or she finds it hard to eat. Warm soups and teas, milk-shakes, ice cream, and soft drinks are all good choices. It is important for the child to drink plenty of fluids to prevent dehydration.

In a few cases, the doctor may recommend a tonsillectomy to prevent recurrence of streptococcal infections.


The prognosis for full recovery from scarlet fever is excellent provided the child is treated with antibiotics. Untreated scarlet fever may have as much as a 3 percent chance of developing into rheumatic fever, the most troublesome complication of scarlet fever. Other possible complications of the disease include ear infections, kidney or liver damage, pneumonia, inflammation of the bones or joints, sinusitis, or meningitis (inflammation of the membranes covering the brain and spinal cord). These complications can develop within eighteen to twenty-one days after the onset of untreated scarlet fever.

Another possible complication of scarlet fever or strep throat is the PANDAS syndrome, a term that stands for Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections. Some children develop symptoms of obsessive-compulsive disorder or Tourette syndrome after a Group A streptococcal infection, or they become moody, irritable, and anxious when separated from their parents. The connection between these symptoms and the infections is not clear, however, and many doctors think that further research is needed.


Forchheimer spots: Tiny reddish spots that appear inside the mouth of a patient with scarlet fever. They are named for Frederick Forchheimer (1853–1913), an American doctor.

Group A streptococcus: A sphere-shaped bacterium that grows in long chains and causes strep throat as well as scarlet fever.

PANDAS disorders: A group of disorders with psychiatric symptoms that develop in some children after strep throat or scarlet fever. The acronym stands for Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections.

Pastia's lines: Bright red lines that appear in the body folds of a patient with scarlet fever after the rash develops. They are named for Constantin Pastia (1883–1926), a Romanian doctor.

Prodrome: A period before the acute phase of a disease when the patient has some characteristic warning symptoms.

Strawberry tongue: A swollen and intensely red tongue that is one of the classic signs of scarlet fever.


Scarlet fever is difficult to prevent completely because of the close contact among children in schools and day care centers. In addition, some

children (and adults) can carry Group A streptococci in their throats without getting sick themselves. When a child is diagnosed with scarlet fever, doctors recommend protecting other family members by washing the sick child's eating utensils, drinking glasses, and (if possible) toys and blankets in hot soapy water, separately from the rest of the family's dishes and laundry. The child should also be reminded to cover the nose and mouth when sneezing or coughing and to wash the hands thoroughly in warm soapy water afterward.

The Future

Since the introduction of antibiotics, scarlet fever is a much less serious disease than it was in the nineteenth century, when it often led to rheumatic fever and other potentially life-threatening complications.

SEE ALSO Ear infection; Obsessive-compulsive disorder; Rheumatic fever; Strep throat; Tourette syndrome

For more information


Jacoby, David B., and Robert M. Youngson. Encyclopedia of Family Health. 3rd ed. Tarrytown, NY: Marshall Cavendish, 2004.

Smith, Tara C. Streptococcus (Group A). Philadelphia: Chelsea House blishers, 2004.


Centers for Disease Control and Prevention (CDC). Group A Streptococcal (GAS) Disease. Available online at (accessed May 19, 2008).

Mayo Clinic. Scarlet Fever. Available online at (accessed May 18, 2008).

Nemours Foundation. Scarlet Fever. Available online at (accessed May 19, 2008).

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Infection: Scarlet Fever

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