Ringworm, also known as Tinea, is a contagious fungal infection of the skin. It is very common, especially among children, and may be spread by skin-to-skin contact, as well as via contact with contaminated items such as hairbrushes. Ringworm spreads readily, as those infected are contagious even before they show symptoms of the disease. Humans can contract ringworm from animals; cats and dogs are often carriers.