Scarlet fever

Scarlet fever is a bacterial infection that typically affects children and adolescents between the ages of 5 and 15. The bacteria that cause scarlet fever belong to the group A Streptococcus genus of bacteria and are capable of producing a specific toxin. This toxin causes the scarlet-colored skin rash that gives the disease its name. Other typical symptoms include fever (high temperature) with a sudden onset, an inflamed throat that appears bright red in color, and difficulty swallowing.

The symptoms are primarily treated with medication to bring down the temperature and prevent inflammation. An antibiotic may also be used. Treatment with antibiotics usually shortens the period for which people remain contagious. As a result, they are able to return to school, daycare, or other community facilities. 

Late complications can occur due to an infection with scarlet fever. However, these are currently a rare occurrence in Central Europe. These late complications can cause permanent damage to the joints, heart, or kidneys.

The symptoms of scarlet fever normally begin very suddenly about one to three days following infection. Typical symptoms of a full-blown infection are a rapidly spiking temperature, chills, and general discomfort. In most cases, a sore throat causes considerable difficulty with swallowing. The throat is inflamed with a bright red appearance and the tonsils usually have a white coating. The lymph nodes may be very swollen, especially in the neck. Younger children in particular may also experience abdominal pain and vomiting. 
 
The bacteria that cause scarlet fever can produce a specific toxin. This toxin is responsible for causing the characteristic rash of red spots on the skin. It develops on the chest, neck, and face on the first or second day of the illness, and can then spread to the rest of the body. The palms of the hands and soles of the feet are not affected. The cheeks appear flushed, while the area around the mouth is typically pale. The rash often has a texture like sandpaper, especially in the groin. A rash may also appear on the mucous membranes inside the mouth. Initially, white coatings are visible on the tongue, before the tongue turns dark red. This symptom is also known as “strawberry tongue”. 
After six to nine days, the rash disappears. A few days later, the skin peels, especially on the palms of the hands and soles of the feet.

There are also A streptococci that do not produce any toxins. If a person becomes infected with one of these bacteria, they can also develop inflammation of the throat and tonsillitis with a high temperature. However, the rash typically associated with scarlet fever will be absent.

Scarlet fever is caused by certain bacteria belonging to the group A Streptococcus (“Streptococcus pyogenes”). 

The main way in which scarlet fever is spread is through person-to-person transmission. When a person is infected, they have a large number of scarlet fever pathogens (i.e., disease-causing microbes) in their throat. When speaking, sneezing, or coughing, these pathogens are released into the air, packaged in tiny droplets. Most infections are caught through direct contact with a person who has scarlet fever. This happens when the droplets they release are inhaled. It can also happen if another person touches a bodily secretion containing the pathogen and then puts their contaminated hand in their mouth or nose. In rare cases, however, contaminated objects, food, or water can also transmit the pathogens.

Scarlet fever is one of the most common bacterial infections in children. It mostly affects 5 to 15-year-olds. Additionally, throat infections caused by A streptococci occur in all age groups. Each year, approximately 5 out of every 1,000 children become ill with scarlet fever. Children in community facilities are particularly affected during the colder months of the year.

The severity of scarlet fever infections can vary widely. Some people get a high temperature and purulent (puss-producing) tonsillitis, while others only have mild symptoms. 
At the present time in Germany, mild cases of scarlet fever are more common than full-blown infections. 

What complications can occur with scarlet fever?

The bacteria that cause scarlet fever mainly colonize the throat. If they are able to multiply unhindered during an infection, they spread via the mucous membranes. One possible complication is the formation of an abscess – a puss-filled cavity – next to the tonsils. Inflammation of the sinuses may also develop. Rare complications of an infection with scarlet fever are pneumonia, a middle ear infection and even sepsis (blood poisoning). 

What late complications can occur with scarlet fever?

Late complications can occur following an infection with scarlet fever. However, these are rare in Germany. There is as yet no evidence to suggest that these late complications can be prevented by treating scarlet fever with antibiotics.

Acute kidney inflammation

In rare cases, inflammation of the kidneys can occur following a streptococcal infection. This typically occurs one to three weeks after the infection and is mild in most cases. The prognosis is good, especially for children. Permanent kidney damage only occurs in rare cases.
In children between the ages of 2 and 12, this type of acute kidney inflammation following a streptococcal infection is the most common cause of inflammation in the filtering units of the kidneys.
When these become inflamed, they become permeable to components of the blood that are otherwise filtered out of the urine. These blood components then enter the urine, potentially making it brown and frothy. The inflammation can cause fluid retention, especially in the eyelids, as well as high blood pressure. Patients may feel exhausted and have abdominal pain and headaches. Other possible symptoms include high temperature and visual impairments. 

Acute rheumatic fever

Acute rheumatic fever occurs primarily in children and adolescents ages 3 to 15, about two to three weeks after the sore throat has subsided. Inflammation typically affects the large joints and the heart. The skin and nervous system are sometimes also affected. Patients may also develop a high temperature and generally feel very week. Severe, permanent damage can develop, including heart valve defects.

There is no vaccine against scarlet fever. To protect yourself from infection, avoid direct contact with people who are ill and still contagious. If contact cannot be avoided, frequent and careful hand washing with soap also prevents infection. Scarlet fever-causing bacteria can easily be removed from objects such as toys using disinfectant. 

Persons suffering from a severe underlying disease or immune deficiency can be protected against infection with preventive antibiotic therapy if the risk of infection is high. In patients suffering from a secondary streptococcal disease, a new streptococcal infection is prevented by taking antibiotics periodically over a number of years.

Scarlet fever can often be recognized by the typical symptoms. There is also a rapid test to detect infection with streptococcal bacteria. In this test, a swab sample is taken from the back of the throat.
If streptococcal bacteria are not detected or if the result is unclear, another swab can be sent to a lab for analysis. 

If doctors suspect that a patient is experiencing late complications of scarlet fever, they will take a blood sample to check whether certain antibodies against the pathogen that causes scarlet fever are detectable.

Bed rest, fever-reducing painkillers, and gargling alleviate the symptoms. Scarlet fever can also be treated with an antibiotic, such as penicillin. It is important to take the medication for as long as it is prescribed, even if the symptoms have already disappeared. If a person with scarlet fever takes an antibiotic, the duration of symptoms is shortened by about 16 hours compared with a person who is treated without antibiotics. 

Not every case of scarlet fever requires treatment with an antibiotic – in milder cases in particular, doctors may advise patients against treatment with antibiotics. 
In the past, antibiotics were used excessively to treat many diseases and, as a result, the disease-causing microbes gradually developed increasing levels of resistance to these drugs. Today, antibiotics should only be prescribed when they are really needed.  

There are other measures to prevent the spread of this contagious disease:

Measures for those with an acute infection:
Persons who are ill with scarlet fever or another infection with Streptococcus pyogenes must not visit or attend work in community facilities. Parents of sick children must inform community facilities about the illness. 

Measures for contacts:
In most cases, no special measures are necessary for people who have had contact with an infected person. However, if symptoms develop in the days following contact, a possible infection with scarlet fever must be considered and they should inform their doctor.