Definition

Cellulitis refers to an infection of the skin. It may spread to tissue just beneath the skin's surface. The infection may occur anywhere on the body. It is most common on the face or lower legs.

Causes

Cellulitis is often caused by a bacterial infection. It may come from bacteria that normally lives on the skin or bacteria from other sources. The bacterial infection may be caused by:

  • A minor injury to the skin, such as a cut, scratch, blister, puncture, or bite, that becomes infected and spreads into the surrounding skin
  • Chickenpox blisters that open up and become infected with bacteria
  • Injuries that occur in natural bodies of water that become infected with germs found in the water
  • A cut or abrasion that becomes infected by food bacteria while handling fish, poultry, eggs, or meat
  • Bacteria that enter the body through surgical wounds or a catheter in a vein
  • Infection in a person with diabetes or a weakened immune system
  • Bacteria spreading from an upper respiratory or ear infection
  • Impaired circulation (tends to cause recurrence of cellulitis)
  • MRSA infection —drug resistant infection that can be spread through shared towel or sport equipment

Puncture Wound

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Risk Factors

Factors that increase your risk for cellulitis include:

Symptoms

Symptoms may begin within hours or days and can include:

  • Skin inflammation that begins in a small area and spreads with:
    • Redness
    • Pain or tenderness
    • Swelling
    • Warmth
    • A red streak (possibly)
  • Swollen lymph nodes
  • Fever or chills
  • Fatigue
  • Headache
  • Cellulitis near the eyes may cause pain with eye movements and should be treated urgently

Diagnosis

The doctor will ask about your symptoms and medical history. A physical exam will be done. Expect to answer questions about how the wound occurred. Your doctor will also ask about exposure to animals or natural bodies of water. Your skin will be closely examined. The doctor may use a colored pen to mark the border of the cellulitis. This will help to monitor its progress.

Tests may include:

  • Wound culture—a sterile applicator swabbed across the area and sent to a lab to test for bacteria; will help to determine type of antibiotic to use (not very useful if there is no pus drainage, open wound or an abscess.)
  • Blood tests—to help determine the severity of the infection

To check for gangrene under the skin or evidence that the infection has spread to the bone the doctor may order:

Treatment

The goal is to eliminate the infection and reduce discomfort. Most cases resolve after a week or two of treatment. An infected wound can be cleaned. Dead tissue may be removed.

A collection of pus may develop. This is called an abscess. It can be drained.

Severe cellulitis, cellulitis in a person with diabetes or a person with a poor immune system, or an infection on the face may require hospital care.

Treatment includes:

Medication

Antibiotics may be taken by mouth or injected into a muscle or vein. The method will depend on the severity of the infection.

Take the entire prescription as directed. Make sure to use all the medicine given. If not taken fully, the infection may return.

Supportive Care

This may include:

  • Resting in bed or elevating the infected area higher than your heart.
  • Applying warm or cool compresses to the area.
  • Change your dressings as directed by your doctor.
  • Protect your skin from additional injury.
  • Do not scratch or rub the area.

If you are diagnosed with cellulitis, follow your doctor's instructions .

Prevention

To reduce your risk of getting cellulitis:

  • Keep your skin clean.
  • Moisturize dry skin with lotion.
  • Avoid injury to the skin:
    • Wear protective gear in sports.
    • Wear long pants and long-sleeved shirts when hiking.
    • Wear sandals when at the beach, rather than going barefoot.
    • Be careful around animals. Treat pets with respect to avoid bites.
  • If you or your child has not had chickenpox, talk to your doctor about getting vaccinated.
  • Do not swim in natural waters if you have cuts or sores.
  • Try not to cut yourself during fishing or other water sports.
  • If a small cut, bite, or other injury occurs, carefully tend to the wound.
    • Clean cuts or scrapes with soap and water.
    • Apply antibiotic ointment.
    • Cover with a bandage or dressing.
    • Do not scratch wounds.
    • Call the doctor immediately if the area becomes red or inflamed.
  • Seek prompt medical care for larger wounds or bites.
  • If your legs tend to swell, elevate them several times a day and wear support stockings.
  • Get recommended vaccines for children and adults.