Cellulitis is a common bacterial infection of the deeper layers of the skin that usually occurs when bacteria enter through a cut, wound, or even dry, cracked skin. It typically causes redness, swelling, warmth, and pain in the affected area and may be associated with fever or chills. The condition can spread if not treated, so early care is important. Treatment usually involves antibiotics prescribed by a doctor, along with rest, keeping the affected area elevated (if possible), and pain relief measures. Most people improve within a few days of starting treatment, but you should seek medical attention urgently if the redness is rapidly spreading, pain is severe, or you develop a high fever or weakness.