Ringworm of the scalp is an infection that grows in the outer layer of the scalp and in the hair. It is caused by a fungus, not by a worm. It often looks like round bald patches, but sometimes it looks like dandruff or patches of black dots. It can be treated with prescription medicine and a special shampoo.
You can get ringworm by touching a person or animal that has it or by sharing personal items such as hats, combs, brushes, towels, and pillowcases.