What is cellulitis?

Cellulitis is a common and potentially serious infection caused by bacteria. The bacteria infect the deep layers of skin and tissue beneath the skin.

The first sign of cellulitis is usually red and swollen skin. When you touch the infected area, it often feels warm and tender.

This infection can show up anywhere on the skin. Adults often get it in a lower leg. In children, cellulitis tends to appear on the face or neck.

CELLULITIS ON THE LOWER LEG

Cellulitis causes redness, which may cover the entire area of be blotchy, as shown here.

While cellulitis often develops in a leg, redness and swelling in both legs usually means you have another condition. You could have stasis dermatitis or contact dermatitis.

If you think you have cellulitis, you should get immediate medical care. Caught early and treated, cellulitis usually clears completely without causing any long-term problems.

Without treatment, the infection can spread quickly. The bacteria may travel to lymph nodes and into the bloodstream. This can lead to a blood infection or permanently damage lymph vessels, which are part of your immune system. Other complications can also develop.

When treated before complications occur, most people recover fully. Caught early, your doctor can treat it with oral (take by mouth) antibiotics and good wound care.

After starting treatment for cellulitis, you should notice improvement in 24 to 48 hours. If you don’t, call your doctor’s office. Severe cellulitis may require you to be treated in a hospital.

If you have cellulitis, you’ll notice that the affected area of your body is red and swollen. It may be difficult to tell where the redness ends and normal-looking skin begins. When you touch the area, it feels warm. Pressing on the warm, hard, and swollen skin is often painful.

CELLULITIS ON A PATIENT’S LOWER LEG

In adults, cellulitis often infects a lower leg.

Before you notice signs on your skin, you may feel ill. Some people have a fever, chills, or fatigue. These are all signs of an infection. If you have a severe infection, you may also have intense pain, cold sweats, nausea, drowsiness, or trouble concentrating.

When the infection is severe, some people develop blisters on the red, swollen skin. The lymph nodes nearest the infection may feel swollen. You may see a streak of red in the area, an open sore, or a pus-filled bump.

People who have severe cellulitis may have a rapid heart rate, low blood pressure, or trouble concentrating.

Where cellulitis develops

Cellulitis can appear anywhere in the body. However, adults usually get it on a leg or foot. Children often have cellulitis on their face or neck. Intravenous drug users tend to develop it on an arm or part of their body that they frequently inject.

Who gets cellulitis?

Cellulitis is common, and anyone can get this infection. It’s estimated that 14.5 million cases of cellulitis are diagnosed in the United States each year.

The number of people who get cellulitis is expected to grow. That’s because more people than ever have an increased risk because they are:

  • Middle-aged or older

  • Overweight or obese

  • Diabetic, especially if the diabetes is poorly controlled

All of these decrease the body’s ability to fight an infection.

BANDAGES HELP KEEP BACTERIA OUT

Keeping wounds clean and covered can reduce the risk of getting cellulitis.

What causes cellulitis?

Bacteria cause cellulitis. Streptococcus (strep) and Staphylococcus (staph) are responsible for most cases of cellulitis. MRSA (methicillin-resistant Staph aureus) and other bacteria can also cause cellulitis.

Many of these bacteria live on our skin without causing a problem. However, once they get inside the body, they become harmful.

The bacteria may get inside the body when we injure our skin. An injury can be obvious, such as an open sore or severe burn. Cuts, scratches, and abrasions also provide a way for the bacteria to get inside.

Cracks in the skin offer another way for the bacteria to get in. People who have eczema, athlete’s foot, or very dry skin often have deep cracks in their skin. Bacteria can get into the body through these cracks.

Of course, not everyone who has a skin injury or deep cracks will get cellulitis. The body’s immune system works hard to destroy the harmful bacteria.

What increases the risk of getting cellulitis?

If any of the following apply to you, you have a higher risk.

Diseases and treatments: The following can increase your risk because they either make it easier for bacteria to get inside your body or harder for your body to fight the bacteria:

  • Athlete’s foot

  • Atopic dermatitis (eczema)

  • Cellulitis (already had)

  • Chemotherapy (undergoing)

  • Corticosteroids (taking)

  • Diabetes (poorly controlled)

  • HIV or AIDS

  • Kidney disease (long-term)

  • Liver disease (long-term)

  • Lymphedema

  • Medicine taken to prevent rejecting a transplanted organ

  • Poor circulation and a related condition like stasis dermatitis or a leg ulcer

  • Surgery (recent)

Athlete’s foot can cause tiny cracks in the skin. When bacteria get into the body through these cracks, cellulitis tends to appear in the calf. Treating athlete’s foot early can prevent this.

People who frequently injure their skin: Research shows that the following people, who tend to have more skin injuries, often have a higher risk of getting cellulitis:

  • Athletes

  • Children

  • Drug abusers who use needles to inject drugs

  • Military personnel on active duty

  • Prisoners

  • Residents in a long-term care facility

How is cellulitis diagnosed?

We don’t have a medical test that can diagnose cellulitis. Doctors diagnose it by examining the infected skin and asking questions.

Be sure to tell your doctor about:

  • A recent injury to your skin

  • All medical conditions you have

  • All medications you take

This information can help make sure you get the treatment you need and prevent problems.

To get an accurate diagnosis, some patients need:

Medical tests: While a test cannot tell whether you have cellulitis, testing can tell what germs are causing an infection.

A referral to a dermatologist: If you are seeing a doctor other than a dermatologist, you may be sent to a dermatologist. Cellulitis can look like other skin conditions and infections.

Dermatologists have extensive training in diagnosing the many conditions that can look like cellulitis. An accurate diagnosis is essential to clear your skin condition.

How is cellulitis treated?

If you are diagnosed with cellulitis, treatment is important. It can prevent cellulitis from worsening. It can help you avoid serious medical problems like blood poisoning and severe pain.

To treat cellulitis, doctors prescribe:

Antibiotics: An oral (you take by swallowing) antibiotic can effectively clear cellulitis.

The type of antibiotic you need and how long you’ll need to take it will vary. Most people take an antibiotic for 7 to 14 days. If you have a weakened immune system, you may need to take the antibiotic for longer.

If you stop taking the antibiotic early, there is a risk the antibiotic won’t kill all the bacteria that made you sick. Taking all of the antibiotic exactly as prescribed helps clear cellulitis.

Some people need to take more than one type of antibiotic.

Sometimes, the antibiotic is given through an IV. When this is necessary, a hospital stay is often prescribed. This can help clear severe cellulitis or cellulitis on the face. Most people are hospitalized for just over one week.

Wound care: This is an important part of treating cellulitis. Covering your skin will help it heal. If you need special wound coverings or dressings, you’ll be shown how to apply and change them.

Rest: This can help prevent cellulitis from becoming serious and help your body heal.

Elevation: If you have cellulitis in your leg, keeping your leg elevated can help reduce the swelling and help you heal.

Treatment for another medical condition: If the bacteria got into your body because you have another skin condition like athlete’s foot, it’s important to treat that condition, too.

What is the outcome for someone who gets cellulitis?

With treatment, you should quickly start to see less redness, swelling, pain, and warmth.

If you fail to notice improvement after 24 – 48 hours, let your doctor know.

While cellulitis will clear with treatment, anyone who has had it has a higher risk of getting cellulitis again.

If you’ve had cellulitis, you have a higher risk of getting it again. Even after successful treatment, some people get cellulitis again and again. For most people, the cellulitis develops in the same place every time.

CLEAN AND BANDAGE WOUNDS IMMEDIATELY

This can help reduce your risk of getting cellulitis again.

The following can help decrease your risk of getting cellulitis again:

  1. Avoid injuring your skin. Skin injuries include cuts, scrapes, burns, sunburns, frostbite, stings from bees and other insects, and abrasions. Being careful when you’re doing any activity, including working out, gardening, or cooking can help avoid an injury.

  2. Treat wounds right away. If you injure your skin, immediately:

    • Wash the wound with soap and water.

    • Apply an antibiotic ointment.

    • Cover the wound with a bandage.

    • Clean and change the bandage every day (or as often as your doctor recommends) until the wound heals.

  3. Keep your skin clean and moisturized. Keeping your skin clean washes away bacteria that cause cellulitis. Moisturizing helps prevent cracks in your skin, which can let bacteria into your body.

    An effective way to prevent or reduce dry skin is to apply moisturizer within three minutes of taking showers or baths. If your hands are dry, applying moisturizer after you wash your hands and frequently throughout the day can relieve the dryness.

  4. Keep your nails well-manicured. You could accidentally scratch yourself with a broken nail. When cutting your fingernails and toenails, you want to take care not to injure the surrounding skin.

  5. If you had cellulitis in an arm, have blood drawn from the arm that has not had cellulitis. Be sure to ask the person drawing the blood to take it from a part of your body that has not had cellulitis.

  6. Treat infections promptly. An infection like athlete’s foot or impetigo can lead to cellulitis, so you want to treat it as soon as you notice signs. Dry, itchy skin between your toes can mean athlete’s foot. Sores, red and swollen skin, or blisters can be a sign of an infection.

  7. Treat other medical conditions. Having another medical condition can increase your risk of getting cellulitis again. Working with your doctor to manage conditions like diabetes, eczema, leg ulcers, or periphery artery disease (PAD) can greatly reduce your cellulitis risk.

  8. Treat lymphedema (excessive fluid buildup that causes swelling, usually in an arm or leg). Of all the medical conditions that increase your risk of getting cellulitis again, lymphedema ranks highest. While there is no cure for lymphedema, it can be treated with exercise, compression bandages, elevation, and drainage.

  9. Lose weight. Research shows that if you are overweight or obese and lose weight, you reduce your risk of getting cellulitis again.

  10. Stop smoking. While more research is needed to know whether smoking increases your risk of getting cellulitis again, research suggests it might.

  11. If you drink alcohol, drink in moderation. More research is also needed to know whether alcohol increases your risk of getting cellulitis again. Current research suggests that heavy drinking increases the risk.

    Drinking in moderation means that women have no more than one drink a day and men two.

  12. Check your feet every day to see if you have an injury or infection. Some people fail to notice when they injure a foot.

Repeat flares of cellulitis can be reduced with daily antibiotics

If you continue to get cellulitis after doing what you can to reduce your risk, research shows that taking a low-dose antibiotic can help. This treatment may be recommended for someone who has had cellulitis three or four times in one year.

If you continue to get cellulitis while on an antibiotic, it’s possible that what’s looks like cellulitis may actually be another skin condition. Seeing a dermatologist can help you find out whether you have cellulitis or another condition.