What Is Ringworm?
Ringworm is a skin and scalp disease caused by fungi. It gets its name from the characteristic ring-like rash on the skin. The disease is spread by touching an infected person or animal. It can also be spread by touching objects or surfaces that had contact with the infection. If infected, people often begin itching four to fourteen days after contact. The rash may be scaly, reddened, and circular. Ringworm on the scalp usually makes a bald patch of scaly skin.
Source: Centers for Disease Control and Prevention (CDC)