Cellulitis is a common bacterial skin infection. Cellulitis may first appear as a red, swollen area that feels hot and tender to the touch. In most cases, the skin on your lower legs is affected, although the infection can occur anywhere on your body or face.Symptoms · Risk factors · Diagnosis. Jun 3, - Cellulitis is the result of a bacterial infection that occurs in the tissue underneath your skin. This kind of infection generally is the result of.