Scarlet fever: symptoms, contagious, cause and treatment

Scarlet fever is a childhood disease that mainly affects children aged 3 to 6 years, but a younger child, a baby, an older child or adults can also get scarlet fever. The cause of scarlet fever is infection with a bacterium: the β-hemolytic streptococcus of group A (Group A streptococcus; GAS). Scarlet fever usually begins with symptoms of fever, headache and sore throat and may be accompanied by chills, vomiting, abdominal pain and general malaise. Scarlet fever is a contagious spot disease caused by the same bacteria that also cause strep throat: streptococci. The bacteria produce a toxin that causes a rash that appears 1 to 2 days after the onset of the disease.

  • Cause of scarlet fever
  • Who can get scarlet fever?
  • Incubation period of scarlet fever
  • How does contamination occur?
  • Scarlet fever symptoms
  • Is scarlet fever dangerous for a baby?
  • Prevent scarlet fever
  • Precautionary actions
  • No vaccination
  • Examination and diagnosis
  • Physical and diagnostic examination
  • Differential diagnosis
  • Treatment of scarlet fever
  • Complications
  • Can a child with scarlet fever go to daycare, playgroup or school?

Scarlet fever / Source: Estreya, Wikimedia Commons (Public domain)

Cause of scarlet fever

Scarlet fever is a contagious spot disease caused by infection with streptococci, a common bacterium that can also cause other diseases, such as strep throat, impetigo or erysipelas. This concerns the β-hemolytic streptococcus of group A (Group A streptococcus; GAS).

Who can get scarlet fever?

Anyone can become infected and become ill if they have not yet had the disease. Scarlet fever mainly occurs in children between the ages of three and six years, but adults can also get it.

Incubation period of scarlet fever

The incubation period , i.e. the period between infection with the bacteria and the first symptoms, can vary from 1 to 7 days. However, many people carry streptococci in their throat, nose or on the skin without becoming ill.

How does contamination occur?

From the moment someone is infected until three weeks after the onset of the first symptoms, the patient can infect other people . Sneezing, coughing or talking releases small droplets of saliva containing the bacteria into the air and other people can inhale these tiny droplets and become infected. It is true that not everyone becomes ill after infection. Scarlet fever is contagious during the first 10 days. However, a patient who is treated with an antibiotic is no longer contagious after two days.

Skin rash in scarlet fever / Source: Badobadop, Wikimedia Commons (CC BY-SA-3.0)

Scarlet fever symptoms

The disease usually begins with fever, headache and sore throat and may be accompanied by chills, vomiting, abdominal pain and general malaise. The bacteria produce a toxin that causes a rash that appears 1 to 2 days after the onset of the disease (see photo). The rash initially appears on the neck and chest, then spreads to the rest of the body except around the nose and mouth. These are usually small, bright red spots and the skin with the spots looks like (red) goosebumps and feels like sandpaper. Areas of small pinhead-sized red dots may also appear, known as petechiae. A so-called strawberry tongue or raspberry tongue is created; the tongue first turns white and after three days becomes red, thick and bumpy. The results usually last three days. After a few weeks, the skin often starts to peel, especially on the fingers, fingertips, toes and groin area. The symptoms mentioned last about seven to ten days.

Is scarlet fever dangerous for a baby?

A baby can also get scarlet fever. In principle, you don’t have to do anything if your baby has scarlet fever. If a sick baby does not want to drink (risk of dehydration), belongs to the risk groups (see below) or becomes lethargic and has swollen eyelids, contact your doctor for consultation. Also contact your doctor if your baby starts to suffer from painful joints in combination with fever and shortness of breath after a few weeks. Risk groups include babies with reduced resistance, abnormalities in the ear, nose and throat area, heart defects and babies with Down syndrome.

Strawberry tongue in scarlet fever / Source: Afag Azizova, Wikimedia Commons (CC BY-SA-3.0)

Prevent scarlet fever

Precautionary actions

Prevention is better than cure, as a well-known proverb goes. The best prevention strategies for scarlet fever are the same as the standard precautions against infections:

  • Wash your hands regularly with soap, especially after a heavy cough or sneeze.
  • Do not share used utensils, such as drinking glasses, with other people.
  • If you do not have a paper tissue at hand, hold your hand over your nose and mouth or (even better) cough or sneeze into the crook of your elbow to prevent possible spread of bacteria.
  • After use, throw the handkerchief in a garbage bin and certainly do not use it again.
  • Also teach children to cough and sneeze politely.
  • If your child has scarlet fever, wash his or her drinking glasses, utensils and, if possible, toys in hot soapy water or in a dishwasher.

No vaccination

There is no vaccination against scarlet fever.

Throat of a child with a positive throat culture for streptococcal strep throat / Source: James Heilman, MD, Wikimedia Commons (CC BY-SA-3.0)

Examination and diagnosis

Physical and diagnostic examination

The diagnosis of scarlet fever is made based on the typical clinical features. In addition, if desired, a swab from the throat can be taken or blood tests can be performed to detect the bacteria.

Differential diagnosis

Scarlet fever can be very similar to many other conditions, such as:

  • Acute cutaneous lupus erythematosus (ACLE);
  • side effects of medications;
  • Erythema infectiosum or fifth disease;
  • Erythema toxicum neonatorum (ETN);
  • Exfoliative dermatitis;
  • Pharyngitis (inflammation of the throat);
  • Juvenile rheumatoid arthritis (inflammation of joints and organs at a young age);
  • Mononucleosis (another name is glandular fever, due to swollen glands);
  • Pneumonia;
  • Measles (rubeola);
  • German measles (rubella);
  • secondary syphilis;
  • Toxic shock syndrome (TSS, a serious bacterial disease),
  • Viral exanthema (skin reaction due to a virus); and
  • Kawasaki disease or mucocutaneous lymph node syndrome (MCLS).

Treatment of scarlet fever

Scarlet fever is caused by a bacterium and can therefore be treated with antibiotics (if necessary). Improvement usually occurs after 24 to 48 hours, while most patients have fully recovered after a week.

Complications

Very rarely, the bacteria will spread to other parts of the body. In that case, complications can arise such as a middle ear infection, sinusitis (sinus infection) or glomerulonephritis (kidney filter inflammation), a condition in which filter units of the kidneys, the glomeruli, become inflamed.

Can a child with scarlet fever go to daycare? / Source: Estreya / Grook, Wikimedia Commons (GFDL)

Can a child with scarlet fever go to daycare, playgroup or school?

If a child with scarlet fever feels well, you do not have to keep him at home, but he can simply go to daycare, playgroup or school. A child with scarlet fever is contagious before it becomes ill. The most likely scenario is that other children are probably already infected with the bacteria. Keeping your child at home and isolating does not help prevent the spread of scarlet fever. Do tell the management or teacher that your child has (had) scarlet fever, so that other parents can be warned. They can then monitor whether their child develops symptoms of scarlet fever.

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