Cellulitis is an infection of the deep layers of skin. A break in the skin, such as a cut or scratch, can let bacteria under the skin. This makes the affected skin red, swollen, warm, and sore. The reddened areas have a border you can see. An open sore may leak fluid (pus). You may have a fever, chills, and pain.
Cellulitis is treated with antibiotics taken for 7 to 10 days. An open sore may be cleaned and covered with cool wet gauze. Symptoms should get better 1 to 2 days after treatment is started.
If not treated, cellulitis can get into the bloodstream and lymph nodes. The infection can then spread throughout the body. This can cause serious illnesses, such as osteomyelitis (infection of the bone), endocarditis (inflammation of the inner lining of the heart and heart valves), and sepsis, a life-threatening complication of an infection.