Alternate Names: Skin infection - bacterial

Causes and Risks: The skin normally has many types of bacteria on it, but intact skin is an effective barrier that keeps bacteria from entering and growing within the body. When there is a break in the skin, bacteria can enter the body and grow there, causing infection and tissue reaction to injury (inflammation). The skin tissues in the infected area become red, hot, and painful.

Cellulitis is most common on the face and lower legs although skin on other areas of the body may be involved.

Risk factors for cellulitis include insect bites and stings, animal bite, or human bite; injury or trauma with a break in the skin (skin wounds); history of peripheral vascular disease, diabetes mellitus, or ischemic ulcers; recent cardiovascular, pulmonary (lung), dental, or other procedures; and use of immunosuppressive or corticosteroid medications.

Prevention: Avoid skin damage by wearing appropriate protective equipment when participating in work or sports. Also clean any breaks in the skin carefully and watch for redness, pain, drainage, or other signs of infection. Finally, maintain good general health and control chronic medical conditions. A body that is healthy can more easily fight bacteria before they multiply and cause infection, while a body that is run down has less protection against infection.

Symptoms:

• localized skin redness or inflammation that increases in size as the infection spreads
• tight, glossy, "stretched" appearance of the skin
• pain or tenderness of the area
• skin lesion/rash (macule):
  • sudden onset
  • usually with sharp borders
  • rapid growth within the first 24 hours
• no boils, blisters, pustules, or similar lesions
• thin red line (along a vein) from the cellulitis toward the heart (lymphangitis)
• fever
• other signs of infection:
  • chills, shaking
  • warm skin, sweating
  • fatigue
  • muscle aches, pains (myalgias)
  • general ill feeling (malaise)

• nausea and vomiting
• joint stiffness caused by swelling of the tissue over the joint
• hair loss at the site of infection

Signs and Tests: A physical examination reveals localized swelling (edema). Occasionally, swollen glands (lymph nodes) can be detected near the cellulitis.

• A CBC will show an elevated WBC, and indicates a bacterial infection.
• A blood culture may be performed if generalized infection is suspected.

Treatment: Cellulitis treatment may require hospitalization because the infection may be difficult to treat. Treatment is focused on control of the infection and prevention of complications.

Antibiotics (penicillin type or erythromycin) are given to control infection, and analgesics may be needed to control pain.

Elevate the infected area, usually higher than the heart, to minimize swelling. Apply warm, moist compresses to the site to aid the body in fighting infection by increasing blood supply to the tissues. Rest until symptoms improve.

Prognosis: Cure is possible with 7 to 10 days of treatment. Cellulitis may be more severe if chronic disease is present or if the person is susceptible to infection (immunosuppressed).

Complications:

• tissue death (gangrene)
• sepsis, generalized infection
• meningitis (if cellulitis is on the face)
• lymphangitis (inflammation of the lymph vessels)

Call your health care provider if symptoms indicate cellulitis may be present.

Call your health care provider if you are being treated for cellulitis and new symptoms develop such as persistent fever, drowsiness, lethargy, blistering over the cellulitis, or extension of the red streaks.