Cellulitis

What is cellulitis?

Cellulitis is an infection of the dermal layer of your skin. The infection may also spread to the tissue under your skin. Cellulitis more commonly occurs on your legs or arms, but can occur on any area of your body. A cellulitis infection can cause your skin to swell and separate from the tissue and bone beneath it. Treatment may decrease symptoms such as swelling and pain. Treatment may also stop the infection from spreading, and cure the infection completely.

What causes cellulitis?

Cellulitis is caused by germs called bacteria. The germs can enter your skin through an opening, such as from a bite, rash, scratch, or a cut. You can also get cellulitis if you have an object under your skin that is not normally there. These objects include patches and mesh used for surgery, or items that poke through your skin and get stuck. The following may increase your risk of getting cellulitis:

• Drug use: Using illegal drugs that are injected through the skin increase your risk for a cellulitis infection.
  
  
• Having a weak immune system: Your immune system is your body's defense against infection and disease. When your immune system is weak, it may not be able to fight against the germs that can cause cellulitis. Medical conditions that lead to a weak immune system include HIV, diabetes, and blood vessel diseases.
  
  
• Poor hygiene: Not washing your hands and body often may cause germs to stay on your body. The germs may then enter an open skin area and lead to cellulitis.
  
  
• Previous cellulitis infection: Having had a cellulitis infection in the past increases your risk for more infections.
  
  
• Sharing personal items: Using other people's belongings, such as towels or exercise equipment may increase your risk for cellulitis.

What are the signs and symptoms of cellulitis?

The most common signs and symptoms of cellulitis are redness, warmth, and swelling in the infected skin area. You may have pain and tenderness (pain when touched) in the infected area. You also may have the following:

• Bumps on the infected skin area that may drain pus. You also may have bruises or blisters on the infected skin.
  
  
• Bumpy, raised skin that feels like an orange peel.
  
  
• Fever (high body temperature) with or without shaking chills.
  
  
• Feeling like you are sick, such as with the flu.
  
  
• Red streaking (line) on your skin from the area of your infection.
  
  
• Swollen lymph nodes (small lumps of tissue in your body that help you fight infection).
  
  
• Weakness and dizziness.

How is cellulitis diagnosed?

Your caregiver may know you have cellulitis by looking at, and feeling your skin. Your caregiver will check the skin area that may be infected. Tell your caregiver how long you have had symptoms, and if anything helps decrease your symptoms. Also tell your caregiver if you have had a cellulitis infection in the past. You also may need any of the following tests:

• Blood tests: You may need blood taken to give caregivers information about how your body is working. The blood may be taken from your hand, arm, or IV.
  
  
• Blood and wound cultures: Cultures are done to learn what kind of germ is causing your infection. A culture can be done with a sample of your blood. A culture may also be done by swabbing over a draining area on your skin.
  
  
• Biopsy: During a biopsy, a small piece of tissue from your infected skin is removed. The tissue sample is then sent to a lab for tests. A biopsy may show what germ is causing your infection. A biopsy may also be done to see if your infection is caused by another kind of skin disorder.
  
  
• Imaging tests: Imaging tests may be needed to show how severe (bad) your cellulitis is. Imaging tests may also show if you have another kind of deep infection. You may need the following:
  
  
  • Computed tomography scan: This test is also called a CT scan. A CT scan is an x-ray that uses a computer to take pictures of your infected skin area. The pictures may show if the infection has spread to other nearby areas. You may be given a dye before the pictures are taken to help caregivers see the pictures better. People who are allergic to iodine or shellfish (lobster, crab, or shrimp) may be allergic to some dyes. Tell your caregiver if you are allergic to shellfish or have other allergies.
    
    
  • Magnetic resonance imaging: This test is also called an MRI. During an MRI, magnetic waves are used to take pictures of your infected skin area. An MRI may show caregivers how bad your cellulitis is. It may show if, and where you have pus collecting under your skin. You will need to lie still during an MRI. Never enter an MRI room with any metal objects. This can cause serious injury.
    
    
  • Ultrasound: An ultrasound is a test that looks inside of your body. Sound waves are used to show pictures of your tissues on a TV-like screen. An ultrasound may be done to show if there are areas under your skin where pus has collected.
    
    
  • X-rays: X-rays are pictures taken of the tissues under your skin. An x-ray may show if your skin infection has spread to other tissues.

How is cellulitis treated?

• Medicines:
  
  
  • Antibiotics: Antibiotic medicine is given to kill the germs causing your cellulitis infection.
    
    
  • Pain medicine: You may be given medicine to take at home to take away or decrease pain. Your caregiver will tell you how much to take and how often to take it. Take the medicine exactly as directed by your caregiver.
    
    
  • Steroids: This medicine may be given to decrease inflammation.
  
  
• Abscess drainage: An abscess is a pocket of pus that collects below the skin. An abscess may form when your body is trying to fight an infection. If you have an abscess with your cellulitis, you may need to have it drained. The pus is drained by putting a needle through your skin into the abscess. Draining the abscess may help heal your cellulitis infection.
  
  
• Debridement: Debridement is when your caregiver removes damaged and infected tissue, and cleans your wound. Debridement is done to help prevent a worsening infection and improve healing.
  
  
• Elevation: You may need to elevate your infected limb (arm or leg) at, or above the level of your heart. Elevation helps decrease swelling and pain, and improves blood flow. Pillows, blankets, or rolled towels can be used to keep your infected limb elevated.
  
  
• Pressure stockings or boots: Compression stockings or pressure boots may be needed to help decrease swelling in an infected leg. Ask your caregiver for more information about compression stockings or boots.

How can I prevent cellulitis?

• Do not share personal items: Do not share items such as towels, clothing, and razors with other people.
  
  
• Clean exercise equipment before using it: Make sure that the exercise equipment you use is cleaned with germ-killing cleaner before using it.
  
  
• Take care of your skin: Use lotion to prevent dry, cracked skin. Always follow your caregiver's instructions for taking care of open sores.
  
  
• Wash your clothing and towels: Wash clothing and towels after each use. Using hot water, and soap or bleach may help kill any germs on your clothing and towels.
  
  
• Wash your hands: Wash your hands often to decrease your risk for infection. Always wash your hands after using the bathroom or changing a diaper. Wash your hands before preparing food or eating.

For more information:

Contact the following:

• National Institute of Allergy and Infectious Diseases
  NIAID Office of Communications & Government Relations
  6610 Rockledge Drive, MSC 6612
  Bethesda , MD 20892-6612
  Phone: 1- 301 - 496-5717
  Phone: 1- 866 - 284-4107
  Web Address: www3.niaid.nih.gov
  

When should I call my caregiver?

Call your caregiver if:

• You have a fever.
  
  
• You symptoms do not get better within three days of starting antibiotic medicine.
  
  
• You feel weak and dizzy.
  
  
• You have questions about your cellulitis infection or treatment.

When should I seek immediate help?

Seek care immediately or call 911 if:

• You have a high fever with shaking chills.
  
  
• You have a thin, grayish-brown discharge coming from your infected skin area.
  
  
• You feel a crackling under your skin when you touch it.
  
  
• You have bluish-purple dots or bumps on your skin, or you see bleeding under your skin.
  
  
• You have new swelling and pain in your legs.
  
  
• You have sudden trouble breathing or chest pain.
  
  
• You have worsening pain in the area of your infection.
  
  
• Your heart is beating faster than it normally does.
  
  
• Your skin is flaking or peeling off.
  
  
• The red area on your skin is getting bigger, or you see red streaks coming from the infected area.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your caregivers to decide what care you want to receive. You always have the right to refuse treatment.

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The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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