There is not much you can do to prevent tinea except minimize the environment in which it likes to grow. If your child has ringworm in an area that is warm, dark, and moist, try to make the area cool, light, and dry.
For rash in the diaper area, let the area air out. Keep your child naked between diaper changes or let her run around the house naked for as long as possible. If your child is already wearing underpants, make sure they are loose fitting, allowing air to get in and out. And if the underpants get wet, put on a dry pair as soon as possible.
For the feet, classic athlete’s foot occurs when the feet are sweaty and do not air out regularly. Try to take off your child’s socks after a long period of play, especially on hot days. After a bath, be careful to dry between the toes to prevent moisture from collecting there.
There are many over-the-counter creams available to treat ringworm. They generally contain either medicinal antifungals or other ingredients that help reduce the number of fungi and make the environment less conducive to the growth of fungi. In general, apply only a thin layer of cream. Remember that the wetter the area, the more likely it is that fungi will continue to grow, even if the moisture comes from an antifungal cream.
When does my doctor need to be involved?
Your doctor does not need to see your child if she has a garden-variety ringworm rash. However, if the rash spreads, persists for a long time (weeks), causes significant discomfort such as itching or burning, or begins to look as though it is secondarily infected with bacteria (it becomes red, warm, and inflamed), your doctor should take a look.
What tests need to be done, and what do the results mean?
Tinea is fairly easy for a doctor to diagnose by sight, making tests unnecessary most of the time. However, if there is uncertainty, the rash can be scraped so that a few cells can be inspected under a microscope. If a microscope is not readily available, the sample can be sent to a laboratory, where the fungi can grow in a culture.