Cellulitis is a bacterial infection that affects the skin as well as the soft tissues under the surface of the skin. This kind of an infection usually occurs when bacteria enter normal or broken skin and start spreading under the skin into the soft tissues. This causes inflammation and infection in the affected parts of the skin. Cellulitis can either be caused by exogenous bacteria or even by the normal flora of the skin. Cracks in the skin, bruises, cuts, open wounds, surgical wounds, insect bites, burns, and blisters are common sites where such infections develop. Although cellulitis may affect any part of the body, usually the skin on the legs and face are primarily affected by this disease.