Ringworm is a fungal infection of the skin, which is usually harmless but highly contagious. It starts as a round spot that slowly becomes larger. The spot may itch. The edge of the spot is red and scaly. The spot looks like a ring, hence the name ringworm. However, it has nothing to do with worms.


Ringworm occurs when there are fungi found on the skin. The fungi that cause ringworm are called dermatophytes. These dermatophytes live on the top layer of the skin, the stratum corneum. They cannot grow into the depth, but they can penetrate into the hair follicles. There are several types of fungi that can cause ringworm. The most common type is called Trichophyton rubrum, other species are Trichophyton tonsurans, Mycosporum canis, and Epidermophyton floccosum. Fungi are everywhere and are contagious. After infection, it takes ten to twenty-one days before the first symptoms occur.
The fungi spread by fungal spores, tiny spheres that appear in many places. Fungi are easy to acquire, for example by walking around barefoot in gyms, swimming pools and other public areas. A fungal infection is usually acquired by contact with people or animals with a fungal infection. Children can have it from other children at school or in the nursery.


During a ringworm infection, red scaly spots emerge. These spots have a size of about one centimeter in diameter. If the patient has a light skin, the spots are pink with a dark red ring on the outside. If a person has a darker skin tone, then the spots are light brown with a dark brown ring around it. If the fungus is located on the head, there is a chance that the hairs break and the person gets a bald spot. Apart from rash, a patient can also suffer from itch, swelling of the skin and secretion of moisture.


The diagnosis of ringworm is often based on how it looks. Some material is sometimes taken in order to be examined under the microscope or to be grown on fungi in the laboratory. Occasionally, a skin biopsy is done. It can sometimes take several weeks before the result of a fungal culture is known.


Fungi are combated with an antifungal medication. These are available in the form of local products (creams, lotions, ointments) and as tablets. In case of ringworm, it usually succeeds to get rid of the spot with a locally applied antifungal cream.
Antifungal creams can be obtained on prescription from the general practitioner or dermatologist. There are also creams for fungi that can be bought without prescription at the drugstore or pharmacy.
If a cream helps insufficiently or when there is an extended fungal infection, then it’s wiser to take antifungal tablets. The tablets are also used in patients who have an impaired immune system.


After treatment, the fungal infection completely disappears without leaving a trace. However, it is possible to get re-infected later in life. It seems to be that one person is more susceptible to fungal infections than others.