Cellulitis is a common infection of the skin and the soft tissues underneath the skin. It occurs when bacteria invade broken or normal skin and start to spread just under the skin or in the skin itself. This results in infection and inflammation. Inflammation is a process in which the body reacts to the bacteria. Inflammation may cause swelling, redness, pain, or warmth.
- People at risk for getting cellulitis include those with trauma to the skin or other medical problems such as the following:
- Circulatory problems such as inadequate blood flow to the limbs, poor venous or lymphatic drainage, or varicose veins
- Liver disease such as chronic hepatitis or cirrhosis
- Skin disorders such as eczema, psoriasis, or infectious diseases that cause skin lesions such as chickenpox
Causes of Cellulitis
Causes of cellulitis include:
- Injuries that break the skin
- Infections related to a surgical procedure
- Any breaks in the skin that allow bacteria to invade the skin (examples are chronic skin conditions such as eczema or psoriasis)
- Foreign objects in the skin
- Infection of bone underneath the skin (An example is a long-standing open wound that is deep enough to expose the bone to bacteria. Sometimes this occurs in people with diabetes who cannot feel their feet.)
Cellulitis can occur in almost any part of the body. Most commonly it occurs in areas that have been damaged or are inflamed for other reasons, such as inflamed lesions, contaminated cuts, and areas with poor skin condition or bad circulation. The common symptoms of cellulitis are as follows:
- Redness of the skin
- Red streaking of the skin or broad areas of redness
- Pain or tenderness
- Drainage or leaking of yellow clear fluid or pus from the skin
- If the condition spreads to the body via the blood, then fevers and chills can result.
When to Seek Medical Care for Cellulitis
Call your doctor if you have any of the following signs or symptoms of cellulitis:
- Fevers or chills
- Redness on the skin
- Red streaks from skin
- Increased warmth
- Drainage from the skin
Go to the hospital's emergency department if you have any signs or symptoms of cellulitis, especially the following:
- High fevers or chills
- Nausea and vomiting
- Obvious enlargement or hardening of the reddened area
- Increasing pain
- Numbness of the reddened or tender area when touched
- Other medical problems that may be affected by even a minor infection
Exams and Tests for Cellulitis
Most likely the doctor will make the diagnosis of cellulitis from a medical history, physical exam, and these exams and tests:
- The doctor may also draw blood for testing if he or she feels the infection is severe enough to be in the bloodstream.
- The doctor also may order an X-ray of the area if there is concern that a foreign object is in the skin or that bone underneath is infected.
- The doctor may try to draw fluid from the affected area with a needle and send the fluid to the laboratory for a culture.