Even a small cut, bite, or scratch can become infected by germs (bacteria). If this infection spreads to deeper layers of skin, it can become very serious. Cellulitis can affect any part of the skin, but it's often found on the face, arms, and legs. It can't spread from person to person. Certain bacteria can cause cellulitis in children even if there is no cut or scratch. So if a lesion develops that is red and painful, make an appointment for your child to see a health care provider right away.