Pediatrics

The scarlet fever test

Definition - What is a Scarlet Fever Rapid Test?

The scarlet fever test detects the bacteria that cause scarlet fever.
The rapid test is done by taking a throat swab with a small stick. This throat swab shows within a few minutes whether bacteria have been found or not. Most of the time, this rapid scarlet fever test is performed by the pediatrician, but there are also tests for at home. If the suspicion of scarlet fever is confirmed, a visit to the doctor must still be made to initiate antibiotic therapy. In addition, the test can be negative despite the presence of scarlet fever, which is why a visit to the doctor is important.

Can I do the quick test myself?

In principle, anyone can do the test themselves. Small rapid scarlet fever tests are available from the pharmacy.
It is important to carry out the test correctly. You actually have to reach the back of the throat with the test stick. This is usually not a problem when parents perform the test on their children, but it is difficult as an adult to take your own throat swab. Basically, scarlet fever is a highly contagious infection that requires rapid antibiotic treatment. Therefore, if you suspect scarlet fever, regardless of whether the rapid test at home turned out positive or negative, you should visit a doctor.

You might also be interested in: How contagious is scarlet fever?

Is the doctor's test safer?

The doctor's quick scarlet fever test is the same one that can be purchased for home use. It therefore does not differ in test security.
However, if the test is negative despite the high suspicion of scarlet fever, the doctor can also send the throat swab to the laboratory. There one tries to breed the triggering bacteria, i.e. the streptococci, so that they can be detected. This procedure is a much more reliable detection of the pathogen, but it is also more complex, which is why the doctor first resorts to the rapid test.

Also read: Treatment of scarlet fever

Where can I get the test from?

The scarlet fever test is usually available at the pharmacy. You don't need a prescription to buy the test.

The scarlet fever test is also available on the Internet. Depending on the provider, however, caution should be exercised here. After all, you cannot rely on everything that is offered and sold on the Internet. Instead, it is better to go to the nearest pharmacy. This is usually faster than ordering online, and pharmacies are only allowed to sell tested and approved tests.

What does it cost?

The scarlet fever test is available online for fifteen to twenty euros. A pack with ten test strips is usually offered. You can also purchase “used” packs that have already been opened and only some of the tests have been used. These tests are correspondingly cheaper, but also less reliable.

A test pack with ten samples also costs around fifteen to twenty euros in the pharmacy.

Both online and in pharmacies, larger (usually twenty pieces) and smaller (usually five pieces) packs are also available.

Does the health insurance company cover the costs?

If you buy the test yourself, whether online or in a pharmacy, the health insurance company usually does not cover the costs. Due to the low price, the takeover would hardly be worthwhile, since such tests would not require a minimum equity participation of five euros.

If the test is carried out by the pediatrician (or, in the case of adults, by the family doctor), the latter will bill the test as normal via his practice system. Since the test in this case was classified as medically sensible and necessary by a doctor, it is covered by the health insurance.

execution

There are different models for the scarlet fever test, but they all work on the same basic principle.

First of all, everything should be carefully prepared. The test often consists of a stick which is initially still wrapped in sterile packaging. In addition, a liquid is required in which the swab should be immersed after the smear. In some tests, this liquid has to be mixed together from several components. In this case, there are specific quantities in the package insert. The test liquid should be mixed according to these instructions. Then you set it up so that it can be easily reached with the test stick and at the same time cannot be knocked over during the test. While in some tests the liquid changes color in the case of a positive smear, in other tests the swab or liquid must be placed on another test medium. This should also be ready.

The throat swab is now taken with the freshly unpacked stick. It is important that deep parts of the throat are also reached. If the tonsils are abnormal, a smear should also be taken from there. The stick must then be placed in the liquid for a few minutes (please refer to the package insert for the exact time). If necessary, some liquid or the stick itself is then placed on the test strip. The test result can be read after a few minutes (see the package insert for times).

You might also be interested in this topic: Complications of scarlet fever

How reliable is the test?

As with any test, the scarlet fever test can show errors.
On the one hand, sick people can receive a negative test result and thus be rated as false negative. On the other hand, the test can give false positive results, so people without scarlet fever infection will still get a positive test result. Both mistakes should be kept in mind when taking a throat swab. If in doubt, the doctor responsible can also send the throat swab to a laboratory, where more detailed and more reliable tests are carried out.

Also read: The symptoms of scarlet fever

At what stage of the disease is the test positive?

Scarlet fever has an incubation period of around two to four days. The incubation period is the time between infection with the bacterial pathogens and the appearance of the first symptoms. Affected persons are already contagious during the incubation period without knowing that they have scarlet fever.

As a rule, a test is only carried out when the symptoms are already present, so the test is then always positive. It also takes a few days beforehand, as the bacteria first have to colonize the pharynx before they can be detected in the rapid test.

You may also be interested in this topic: That's how long scarlet fever lasts

Are there different tests for adults / babies / children or pregnant women?

The normal rapid scarlet fever test examines affected people for a specific strain of the causative bacteria. He can only detect streptococci A. This rapid test is used by adults as well as children and babies and is carried out via a throat swab.

You can also test for streptococci B during pregnancy. These bacteria are found in the intestines of many healthy people and do not cause disease there. However, they can be passed on to the child at birth. Because babies do not yet have a well-developed immune system, the newborns can develop the infection. Therefore, a streptococcal B test is useful as part of prenatal care. If the test result is positive, the mother is given antibiotics during childbirth so that the pathogens are not transmitted to the child.

You can find additional information at:

Scarlet Fever in Pregnancy
Scarlet fever in the baby

Can the test also be false positive?

The scarlet fever test, like any other test, can show false positive results. This could be due to contamination that was already in the test utensils.

But the smear itself can also trigger a false positive result. There are different types of streptococci, the scarlet fever-causing pathogens. The rapid test usually only detects streptococci A. However, in some cases the test results have been positive even though the affected person had a different streptococcal strain in their throat. The antibiotic treatment following the positive test result is, however, also very useful when colonizing with other streptococci.

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