Scarlet Fever

Also called: Scarlatina, Scarlet Fever Disease

Reviewed By:
Robert Daigneault, M.D
Rafiu Ariganjoye, M.D., MBA, FAAP

Summary

Scarlet fever is a bacterial infection that results in a characteristic red skin rash. It is caused by the same bacteria that cause strep throat and the two conditions frequently occur together.

Streptococci bacteria can invade the body and cause throat inflammation and strep throat. Some of these cases also develop into scarlet fever, which may also include a rash, fever and enlarged tongue. The symptoms develop quickly, only a day or two after exposure to the bacteria.

Scarlet fever is passed through fluids of the nose and mouth, often by coughing, sneezing or having direct contact with an infected person. Scarlet fever can occur at any age, but is most common among children, who spread it readily in schools and daycare centers.

Physicians can diagnose scarlet fever by identifying the characteristic rash. They also may take a swab from the back of the throat to perform a culture or rapid strep test to confirm the presence of streptococcal bacteria. Scarlet fever is easily treated with antibiotics and other measures to alleviate symptoms of the rash or fever. Prevention methods revolve around good hygiene and keeping patients from transmitting the disease for several days after they begin antibiotic therapy.

The effect of scarlet fever on public health has changed dramatically in the past 100 years. Before antibiotics were available, scarlet fever was a common cause of serious childhood illness and death, mostly occurring when its complications affected other body systems. Quarantining patients in their homes was the only way to prevent transmission and minimize epidemics. With the antibiotics available today, scarlet fever can be readily cured within a few weeks and rarely causes serious complications. Most patients who have scarlet fever develop immunity to it and do not contract it again.

About scarlet fever

Scarlet fever is an upper respiratory disease characterized by a red skin rash and high fever. The rash is caused by an allergic reaction to toxins produced by streptococcal A bacteria, the same bacteria that cause strep throat.

Streptococcal bacteria normally can live on healthy skin and may cause no problems. When the bacteria get inside the body, they can cause strep throat, impetigo or cellulitis. Untreated, strep throat can develop into scarlet fever. In rare cases, other streptococcal infections may cause scarlet fever, but most cases originate with strep throat.

The rash associated with scarlet fever can affect most parts of the body, except the area around the mouth. It may itch or feel like a sunburn and after several days begins to peel.

Although it can occur at any age, scarlet fever usually affects children, though some children may be more susceptible than others. The bacteria can be transmitted through mouth and nasal fluids or droplets, either directly by coughing or sneezing or sometimes from objects an infected person has touched. The disease is commonly spread in areas of close contact such as schools and daycare centers. Scarlet fever occurs more often in colder months when children spend more time indoors and in close contact.

The disease is easily treatable with antibiotics. However, left untreated, scarlet fever can infect other body systems and create other serious inflammations. Rheumatic fever can inflame connective tissue such as heart valves and damage them permanently. Glomerulonephritis is a kidney inflammation that may eventually lead to kidney failure.

The advent of antibiotics has changed the course of scarlet fever. Before the middle of the 20th century, scarlet fever was a serious and often deadly childhood illness. Patients were quarantined in their homes for weeks and often their belongings were burned. People who later developed rheumatic fever spent months convalescing. Current antibiotic treatment and attention to hygiene has eliminated the need for quarantine. Most people who contract scarlet fever develop immunity to further infection with the same strain of the bacteria.

Risk factors and causes of scarlet fever

Scarlet fever is caused by infection with group A streptococci bacteria. Exposure to the bacteria may lead to infection in various parts of the body, including the throat and skin, as is seen in scarlet fever. Thus, a strep throat infection is a major risk factor for developing scarlet fever. However, only a small percentage of people with strep throat infections go on to develop scarlet fever. In rare cases, other streptococcal infections such as the skin infection impetigo may also lead to scarlet fever and may be considered a risk factor.

The bacteria can spread through direct contact and through droplets in the air. Close contact with infected people (e.g., children in school or daycare centers) can spread the disease. Scarlet fever usually occurs where strep throat infections are common, such as among school-age children in winter or spring months in colder climates.

Signs and symptoms of scarlet fever

Scarlet fever usually begins with a sore throat and a fever of 101° Fahrenheit (38.3° Celsius) or higher. The sore throat may include enlarged tonsils with a white, yellow or gray mucus coating. The patient’s tongue may have a white coating and the bumps on the tongue (papillae) may be enlarged, making the tongue look like a strawberry. Vomiting, chills, abdominal pain and swollen neck glands may also occur. In the rare cases that do not develop from strep throat, the patient may not have a sore throat.

The skin rash associated with scarlet fever begins a day or two after infection. The rash may first appear on the neck and then spread to the chest, abdomen and other extremities. It may occur on the face, although not around the mouth, which remains paler than the rest of the face. The red rash has small bumps that may feel like sandpaper and may itch, but is usually not painful. Areas of skin creases, such as the underarms and groin, may have deep red streaks (Pastia sign). The rash fades about four days later and the skin begins to peel. Skin peeling may last for up to a month.

Diagnosis and treatment for scarlet fever

The rash that accompanies scarlet fever is unique and may be readily identified by a physician. The physician will also compile a medical history, including any potential exposure to infection, and perform a physical examination. Although scarlet fever is not usually difficult to diagnose, milder cases (in which throat examination does not conclusively show strep infection) may resemble other conditions, such as rubella.

Identification of the Streptococci bacteria is also important. A physician or nurse may use a swab to take a sample of material from the back of the throat. A rapid strep test of this sample may identify strep throat in about five to 10 minutes. A throat culture takes two to three days to identify strep throat as the source of the scarlet fever.

Physicians treat scarlet fever with antibiotics. Patients should remain away from school, work or other public areas until they have taken antibiotics for at least 24 hours. The antibiotic prescription should be used until it is finished (usually 10 days), even if the symptoms have subsided.

Other symptoms of scarlet fever may also be treated to make the patient more comfortable. Foods and beverages to soothe a sore throat include soup and ice cream. Patients should drink plenty of liquids. A pain reliever such as acetaminophen may be given to children with fever. Children with fever should never take aspirin because of the potential for developing Reye syndrome.

Prevention methods for scarlet fever

The bacteria that cause scarlet fever can be passed through direct contact and through droplets in mucus and nasal fluids. Close contact with an infected person or items they have used can spread the disease.

Good hygiene is one of the best ways to prevent transmission. Regular handwashing and carefully separating and washing utensils and dishes used by an infected person can help prevent transmission. Avoid touching hands to the eyes, nose or mouth.

Infected patients should be kept out of work, school or daycare until they have been treated with antibiotics for at least 24 hours. Schools or daycare centers should be notified if a child contracts scarlet fever so other children and parents can attempt to prevent further transmission.

If a child frequently gets strep throat, a physician may recommend tonsillectomy (removal of the tonsils) to prevent future strep infections.

Tonsillectomy

Questions for your doctor about scarlet fever

Preparing questions in advance can help patients and parents have more meaningful discussions with their physicians regarding their or their child’s treatment options. The following questions related to scarlet fever may be helpful:

How does scarlet fever differ from strep throat?
I have read books where scarlet fever was an extremely serious illness. Why does it seem less serious now?
Will my child continue to get strep throat after having scarlet fever?
Can any sore throat develop into scarlet fever?
Will treating my child’s rash cure the scarlet fever?
Is it possible to have scarlet fever without a fever?
My child took all the antibiotics and her skin is still peeling. Is this normal?
Can scratching the scarlet fever rash transmit the disease?
How much should I limit my child’s contact with the rest of the family?
Can my child contract scarlet fever a second time?
Should I be concerned about rheumatic fever?