Scarlet Fever: Causes, Symptoms

Scarlet fever (Scarlatina) is an infectious disease characterised by fever, tonsillitis and skin changes - typically a rash. In the past, scarlet fever had a severe course and serious complications. It is a highly contagious disease affecting mainly children.

Scarlet fever is characterized by a combination of tonsillitis and a typical rash. It is one of the most common infectious diseases. In the last 10 years, 3000-5000 cases have been reported per year.

The incidence is higher in spring and is mainly transmitted in collectives. It is caused by a streptococcus bacterium (Streptoccocus haemolyticus group A). This bacterium produces substances (so-called toxins) that enter the skin through the blood and are responsible for the skin manifestation: a rash.

How can a child become infected?

The infection can be acquired from a sick person or a bacillus carrier. The most common form of transmission is through the airborne route - droplet infection, airborne, and less commonly through direct contact or contaminated objects.

Streptococcus produces several types of toxin, against which the child's body develops antibodies, and immunity develops.

However, if the child becomes infected with other types of streptococcus, and the organism does not recognize other toxins, the disease comes again with angina or with a rash - scarlet fever. Therefore, scarlet fever can recur even several times a year.

The incubation period is usually 2-4 days.

Once the disease agent enters the body, it produces toxins that are released into the bloodstream and contribute to the development of disease symptoms.

The cause of its occurrence is contact with an infected person. Infection is mostly transmitted in groups among classmates or in the home environment where people are in close contact. Small droplets that spread through the air are the source of infection.

NOTE:

It is important to know that it is not only the acutely ill person who carries the disease, but also the person "after the illness" or the bacillus carrier (the person who carries the disease but is currently asymptomatic).

The blood route is also a possible form of transmission, most often when the skin is injured or the integrity of the skin is compromised. If the streptococcus produces a toxin, it passes into the body through the injured skin, resulting in early scarlet fever. In this form of the disease, tonsillitis is absent or develops later. 

Initial symptoms can appear in as little as a day, up to a week, but most often the incubation period is around 3 days. At its onset, the disease is very similar to classical angina.

Symptoms can be:

• general
• in the oral cavity
• on the skin

Table: symptoms of scarlet fever

On the face, the skin is red and the skin around the mouth is pale, but there are no rashes. Typical of scarlet fever is peeling of the skin, which starts after 2 to 4 weeks after infection. It is more pronounced on the palms of the hands, flat parts of the feet, or fingers and toes.

If the skin changes were less pronounced, the peeling of the skin is only minimal or completely absent.

If the infection enters the body through the injured skin, not through the respiratory tract, tonsillitis is not always present. There is only a skin finding, but the treatment and complications are the same as after scarlet fever with tonsillitis.

When suspecting scarlet fever, the doctor checks the throat and nodes, with the help of anamnesis (interview) asks about temperature, chills, nausea, loss of appetite.

Diagnosis is determined on the basis of clinical symptoms. The most characteristic signs are raspberry tongue and rash. With the typical finding of tonsillitis with fever and a characteristic rash, establishing the correct diagnosis is not a problem.

Nevertheless, we do a throat culture (swab) before giving antibiotics.

A rapid streptococcal ASLO (antistreptolysin O) test is also used - these are antibodies that the body makes against the product of the streptococcus (streptolysin O). ASLO levels increase at the end of the 1st week of illness, reach a peak between the 3rd-5th week and gradually decrease.

In the blood, the inflammatory markers CRP (C-reactive protein) and white blood cell count are elevated.

The onset of the disease and the general symptoms are identical to those of ordinary streptococcal tonsillitis.

• Fever - It usually appears unexpectedly. It is accompanied by chills and nausea. With the retreat of the rash, the temperature, as a rule, decreases.
• Vomiting and nausea - In children, they are frequent and come right after an increase in body temperature.
• Sore throat - All shortly after the temperature rises. Pins and purulent coatings appear on the almonds. The tongue is white-coated at the onset of the disease; in two to three days the coating peels off and a typical raspberry tongue develops. 
• Lymphadenopathy - The lymph nodes in the neck are enlarged and painful to the touch.
• Rash - It appears between 12 and 24 hours after the outbreak - it first appears in the lower abdomen, later on the trunk, and quickly spreads to other parts of the body.
• Peeling (exfoliating) skin - The rash begins to subside after 3 to 4 days, and the skin begins to peel due to increased cornification of the skin.

There is also a light red colour, reminiscent of goosebumps. In some patients it is often barely visible, the skin may be only rough to the touch. Small peetchiae may also be present (Rumpel-Leed sign).

The reason for these changes is the expansion and increase in the permeability of the capillaries. 

Correct diagnosis and complications

Before the doctor makes a diagnosis, he or she will test the blood for streptococcus and take a throat swab, but the disease may also resemble other commonly occurring diseases in our country:

• Rubella and measles – The rash progresses from the head to the trunk, and thanks to vaccination, their occurrence in children is very rare.
• Viral eczanthema – A rash that accompanies a viral illness.
• Toxoallergic eczanthema – Rash caused by external exposure to allergens.

Complications

Early detection and treatment of scarlet fever carries almost no risks. However, the opposite can occur if the disease is caught at a late stage.

Table: Types of complications due to scarlet fever.

A frequent complication, although very rare after the discovery of penicillin, is rheumatic fever. The latter manifests itself in joint, heart and brain involvement and occurs 2 to 3 weeks after the disease is over.

Learn more:
Rheumatic fever in children: Causes and Manifestations