Cellulitis Skin Infection Causes, Symptoms, Diagnosis and Treatment Information by MedicineNet.com

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Cellulitis

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Medical Author: Melissa Conrad Stöppler, MD
Medical Editor: William C. Shiel Jr., MD, FACP, FACR

Cellulitis Symptoms

Medical Author: Melissa Conrad Stöppler, MD
Medical Editor: Dennis Lee, MD

Cellulitis is a painful bacterial skin infection. What is cellulitis?

Cellulitis is a common infection of the lower layers of skin (dermis) and the subcutaneous tissues (areas underneath the skin) caused by a bacterial infection. While cellulitis sometimes develops around wounds in the skin or surgical incisions, in other cases it arises without an obvious source for the bacterial infection. Staphylococci are the bacteria that most commonly cause cellulitis, followed by Streptococci. Less commonly, other types of bacteria may cause cellulitis.

What are the symptoms of cellulitis?

Cellulitis usually begins as a small area of pain and redness on the skin. This area spreads to surrounding tissues, resulting in the typical signs of inflammation � redness, swelling, warmth, and pain. A person with cellulitis can also develop fever and/or swollen lymph nodes in the area of the infection.

Who is at risk for cellulitis?

Anyone may develop cellulitis. Males and females and people of all races are equally likely to become infected. However, people whose immune systems are weakened for any reason (including from chemotherapy for cancer or other immune-suppressing drugs) and those with diabetes are at highest risk for developing cellulitis.

Find out how cellulitis is treated »

What is cellulitis? What are symptoms of cellulitis?

Cellulitis is a spreading bacterial infection of the skin and tissues beneath the skin. Cellulitis usually begins as a small area of tenderness, swelling, and redness. As this red area begins to enlarge, the person may develop a fever -- sometimes with chills and sweats -- and swollen lymph nodes ("swollen glands") near the area of infected skin.

Unlike impetigo, which is a very superficial skin infection, cellulitis refers to an infection also involving the skin's deeper layers: the dermis and subcutaneous tissue. The main bacteria involved in cellulitis are Streptococcus and Staphylococcus ("staph"), the same bacteria that cause many cases of impetigo. MRSA (methicillin-resistant Staph aureus) can also cause cellulitis. Sometimes, other bacteria (for example, Hemophilus influenzae, Pneumococcus, and Clostridium species) may cause cellulitis as well.

Where does cellulitis occur?

Cellulitis may occur anywhere on the body, but the leg is the most common site of the infection (particularly in the area of the tibia or shinbone and in the foot), followed by the arm, and then the head and neck areas. In special circumstances, such as following surgery or trauma wounds, cellulitis can develop in the abdomen or chest areas. People with morbid obesity can also develop cellulitis in the abdominal skin. Special types of cellulitis are sometimes designated by the location of the infection. Examples include periorbital (around the eye socket) cellulitis, buccal (cheek) cellulitis, and perianal cellulitis.

What does cellulitis look like?

The signs of cellulitis include redness, warmth, swelling, and pain in the involved tissues. Any skin wound or ulcer that exhibits these signs may be developing cellulitis.

Other forms of noninfected inflammation may mimic cellulitis. People with poor leg circulation, for instance, often develop scaly redness on the shins and ankles; this is called "stasis dermatitis" and is often mistaken for the bacterial infection of cellulitis.