Ringworm (erythema infectiosum) is a viral disease that occurs primarily in children. It is highly contagious and is transmitted by droplet infection. A typical symptom is a red skin rash, which primarily appears on the face, but can also appear on the arms, legs and trunk. Ringworm usually takes a harmless course and heals on its own after a few weeks. However, complications are possible in adults, especially pregnant women.
Ringworm – What is it?
Ringworm is caused by parvovirus B19 and is common throughout the world. Just like measles, mumps, chickenpox, and rubella, they are among the typical childhood diseases. Ringworm is often confused with normal rubella, but it is actually an infectious disease in its own right. Ringworm is contagious. The viruses are transmitted by droplet infection – for example, when coughing or sneezing. How long it takes after infection for the first symptoms to appear (incubation period) varies: usually the period is between four days and two weeks. The infected person is already contagious during the incubation period; as soon as the first symptoms appear, the risk of infection is only slight. Once you have contracted ringworm, you are immune to the disease for the rest of your life. However, since the symptoms caused are usually only very mild, many affected persons do not even know that they are ill. It is estimated that in Germany about half of the population is immune to ringworm.
Red skin rash as a typical symptom
With ringworm, symptoms similar to those of a cold are often noticeable at first: thus, fatigue, fever as well as aching limbs may occur. The most characteristic symptom, a red skin rash, occurs in only about one in five people. Typically, the rash develops mainly on the face: Large red spots appear on the right and left cheek. The chin, lips and nose, on the other hand, are usually spared the rash. In addition to the face, the rash can also appear on the arms, legs and torso. Often, the spots here have a typical ring-shaped pattern: they have a red border and a lighter inner surface. The severity of the rash and whether or not it is accompanied by itching varies. The same applies to the duration of the skin redness: Usually the symptoms subside after a few days, but in some cases they can last for several weeks. Often the skin is scaly due to the rash and requires particularly intensive care.
Ringworm in adults
Ringworm is considered a harmless childhood disease that usually resolves without consequences. Even for adults, ringworm is usually not dangerous. With increasing age, however, more severe symptoms may occur. For example, adults may experience swelling and inflammation of the joints of the hands and fingers, as well as the knees and ankles. Complications can occur in people suffering from anemia or immune deficiency, such as leukemia patients and people with a transplanted organ. This is because the lack of red blood cells, which can be triggered by the ringworm virus, causes them more problems than healthy people. Ringworm can be particularly dangerous during pregnancy: In about 20 percent of cases, the viruses pass to the unborn child, who may subsequently develop anemia. In the worst case, the virus can cause a miscarriage.
Diagnosing ringworm
Ringworm is usually only noticed in children and adults when the typical red rash appears. If this is absent, the disease usually goes undetected. If you discover an unusual skin rash on yourself or your child, a doctor can usually determine whether it is ringworm or not by a brief examination. Ringworm can be reliably diagnosed by a blood test: During an infection, special antibodies are formed in the blood, which can be detected about ten days after the onset of the disease. Such a blood test is not usually necessary for children – it is usually only carried out on pregnant women, as the viruses pose a particular risk to them.
Treat ringworm
As with most viral diseases, there is no treatment for ringworm per se. Symptomatic treatment is possible, but in many cases it is not necessary because of the mild course of the disease. In cases of high fever, antipyretics may be helpful. However, children should not be given medications containing acetylsalicylic acid, otherwise life-threatening Reye’s syndrome may occur. If the rash causes severe itching, you can relieve the discomfort by applying an appropriate ointment from the pharmacy, such as zinc lotion. In contrast to many other typical childhood diseases, there is no vaccination against ringworm yet. You can only prevent the disease by avoiding contact with infected persons. Pregnant women who do not have antibodies to the ringworm virus in their blood should avoid contact with children in general as much as possible as a precaution.