Cellulitis is a painful inflammatory process that spreads through the connective tissue and is characterized by swelling and edema. It is usually associated with a bacterial infection.

Although cellulitis is not contagious, the same bacteria (e.g. staph and strep) causing the infection can spread from the direct contact of an open sore. Acquiring these bacteria puts you at a greater risk for developing cellulitis, but does not necessarily mean that cellulitis will result. However, you can develop other minor skin infections by the transmission of these bacteria.

Cellulitis is caused by bacteria (usually Streptococcus or Staphylococcus). Some people are at risk for infection by other types of bacteria that result in cellulitis. At-risk groups include people with impaired immune systems and people who handle fish, meat, poultry, or soil without using gloves.

Cellulitis can cause tenderness, pain, swelling, and redness at the site of the infection. Fever and chills are also common. Cellulitis can occur anywhere on the body. In adults, it often occurs on the legs, face, or arms. In children, it commonly develops on the face or around the anus. Facial infection requires immediate medical attention; antibiotics can help prevent a potentially dangerous eye infection.

Complications such as bacteremia (presence of bacteria in the blood) or sepsis (body's response to widespread infection) can develop if the bacteria that cause cellulitis spread quickly through the body. Facial cellulitis infection can spread to the brain (meningitis). Other complications, such as thrombophlebitis or, rarely, gangrene, can also develop.

Antibiotics are the main treatment for cellulitis and are usually successful in curing the infection. Antibiotics can be taken either by mouth or intravenously (IV). If you have certain medical conditions that increase your risk of getting cellulitis, you can take antibiotics after a skin injury to help prevent the infection.

Nonclostridial cellulitis: Infection resulting from the microbial synergism between different anaerobic (w/o oxygen) and aerobic (in the presence of oxygen) bacteria

A cut or injury to the skin, a surgical wound, a skin infection, a burn, or an animal or insect bite. Skin lesions, such as ulcers, eczema, psoriasis, or a fungal infection such as athlete's foot. One study found that inflammation caused by toes rubbing together (toe-web intertrigo) is often a cause of cellulitis in the leg, and that treating this skin inflammation could prevent cellulitis.

Symptoms of cellulitis include tenderness, pain, swelling, and redness at the site of infection. If the infection spreads, you may have fever and chills, along with swollen lymph nodes. Occasionally, if cellulitis causes a high fever, you may have changes in mental function, such as confusion or sleepiness. Cellulitis can occur anywhere on the body, most often on the legs, face, or arms.