Scarlet fever

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at June 16, 2016
StartDiseasesScarlet fever

Scarlet fever, sometimes referred to as scarlatina, is a bacterial infection most often seen in individuals with strep throat. The condition is most common in children and adolescents between the ages of 5 and 15. Advances in treatment have made scarlet fever less of a threat; however, it can still cause serious complications if left untreated.


Definition & Facts

The bacteria that cause scarlet fever are highly contagious and can easily spread among individuals in close contact with infected individuals, such as family members and classmates. If left untreated, scarlet fever can affect various organs in the body, including the kidneys, tonsils, lungs, skin, and middle ear.

In rare cases, scarlet fever can also lead to rheumatic fever, which is an autoinflammatory disease that can cause permanent damage to the heart, central nervous system, skin, and joints. Today, most cases of rheumatic fever are seen in developing countries. In most cases, serious complications can be avoided with prompt antibiotic treatment.

Symptoms & Complaints

The symptoms of scarlet fever typically appear within three days following exposure; however, the incubation period can be as long as a week. The most prominent symptom is a sunburn-like red rash that may have the texture of sandpaper. The skin will typically blanch and turn pale when pressure is applied to the area. The rash usually begins on the face and neck and spreads to the trunk and extremities. Other symptoms include:

The characteristic rash and red tongue typically go away in about a week. The skin may start to peel once the rash resolves. Scarlet fever should never be allowed just to run its course. Anyone experiencing a red rash along with a sore throat and high fever should talk to their doctor as soon as possible. This is especially important for individuals who currently or have recently had strep throat.


Scarlet fever is the result of an infection with the group A streptococcal bacterium, which is the same germ that causes common strep throat. It is unclear why, but the number of cases of scarlet fever has declined while strep throat remains a common illness.

Streptococcal bacteria thrive in the warm, moist environment of the mouth and nasal passages. This means that the infection can be spread when the germs become airborne through sneezing or coughing. A person can also become infected by touching objects that have been contaminated by the airborne droplets and then touching their eyes, nose, or mouth. The infection can also be spread by drinking or eating with the same utensils as an infected individual.

Diagnosis & Tests

The diagnosis of scarlet fever begins with a physical examination. The doctor will check the tongue, throat, and tonsils for signs of redness, swelling, and infection. The doctor will also examine the skin for signs of the tell-tale rash and check for the presence of enlarged lymph nodes.

If the preliminary physical exam leads the doctor to suspect scarlet fever, he or she will likely order a throat culture to check for the presence of strep bacteria. This involves swabbing the back of the throat to obtain a small sample of cells for further analysis. The sample may be sent to a lab where it will be cultured and examined under a microscope. The lab may also perform an antibiotic sensitivity test during which the bacteria are exposed to various antibiotics to determine which one is the most effective.

Many primary care clinics use a rapid strep test that can detect the presence of strep bacteria in a matter of minutes. A blood test may also be used as part of the diagnostic process. Patients with scarlet fever will typically show an increase in white blood cells known as lymphocytes and eosinophils.

Treatment & Therapy

Most cases of scarlet fever can be successfully treated with a 10-day course of antibiotics. Amoxicillin and erythromycin are the antibiotics most often used to treat the infection. The symptoms of scarlet fever may start to improve within a couple of days after starting antibiotics; however, it is extremely important to complete the full course as prescribed to prevent the infection from recurring.

Individuals with scarlet fever should stay home from work or school until their fever has resolved, and they have been on antibiotics for at least 24 hours. Over-the-counter aspirin or ibuprofen may be used to keep the fever under control. It is important never to give aspirin to anyone under 20 who may have an infection since this can cause a rare but dangerous liver disease called Reye’s syndrome.

Calamine lotion and colloidal oatmeal baths may help alleviate the itchiness caused by the rash. Warm or cold foods, such as soups and milkshakes, may relieve a sore throat. Patients should also drink plenty of cool liquids to prevent dehydration, and get as much rest as possible. Most people with scarlet fever recover within four to five days after starting antibiotic treatment.

Prevention & Prophylaxis

Individuals with the condition should limit their contact with others as much as possible. Good hand hygiene is also essential in preventing infection. This includes using tissues or handkerchiefs when sneezing or coughing and washing the hands frequently.

All tissues should be disposed of properly, and handkerchiefs should be washed thoroughly in hot water. Anyone handling these items or touching the face, nose, or mouth of the ill person should wash their hands immediately afterward.

The infected person should not share towels, eating utensils, or clothing with others. Any potentially contaminated toys or surfaces should be disinfected daily. Pregnant women typically do not risk passing the infection to their unborn child; however, pregnant women and the elderly should avoid contact with infected individuals.