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Cellulitis is a skin infection that occurs when bacteria enter broken skin through a cut, scrape, or bite. It can cause swelling, redness, and pain. The skin can also feel warm or hot to the touch.

Though cellulitis is common and can spread quickly throughout your body, it's not contagious.

Call the UPMC Center for Care of Infectious Diseases to learn more or make an appointment at 412-647-7228 or 1-877-788-7228.

What Is Cellulitis?

Cellulitis is a common bacterial skin infection. Each year in the U.S., doctors diagnose about 14 million cases causing nearly 650,000 hospitalizations.

Cellulitis can occur on any part of the body's skin but happens most often on the feet or legs.

Without treatment, the infection can spread and cause potentially serious complications including sepsis.

Sepsis is a life-threatening condition that can occur when bacteria enter the bloodstream and cause the immune system to overreact.

Cellulitis causes

Not all bacteria cause cellulitis, but the most common type that causes these skin infections is group A Streptococcus (group A strep).

Staphylococcus bacteria can also commonly cause cellulitis.

Cellulitis risk factors and complications

Some people are more likely to get cellulitis than others, such as those with:

  • Broken skin injuries, such as cuts, fractures, burns, animal bites, ulcers, scrapes, or scratched-open bug bites.
  • A weakened immune system.
  • Skin problems, such as a fungal infection, eczema, psoriasis, chickenpox, or shingles.
  • Constant swelling of the arms or legs, especially after surgery.
  • Having had cellulitis in the past.
  • A recent tattoo or piercing.
  • Poor blood circulation.

Other people at higher risk of cellulitis are those who shoot illegal drugs and those who are overweight or obese.

If a person with cellulitis doesn't receive treatment, it can cause a worse infection such as sepsis. Sepsis is a dangerous condition that can occur when bacteria enter the bloodstream.

Though rare, cellulitis can also cause other serious conditions, including:

  • Septic arthritis in the joints.
  • Swelling and infection in the bones (osteomyelitis).
  • Infection of the heart's chambers or valves (endocarditis).
  • Swelling of your veins (phlebitis).
  • Flesh-eating disease (necrotizing fasciitis), a severe skin infection that can cause death.

How to prevent cellulitis

There's no vaccine to prevent cellulitis. The best way to prevent it is to protect broken skin from bacteria and practice good hygiene.

Here are tips for avoiding cellulitis:

  • Protect your skin when doing things that pose a higher risk of injury, such as skateboarding, rock climbing, bike riding, or hiking.
  • Don't go near wild animals or other animals that may bite you.
  • Wash your hands often and bathe routinely to keep your skin clean.
  • Use soap and water to clean all cuts and injuries that break the skin, including scrapes and blisters.
  • Don't scratch open bug bites or pop blisters on purpose.
  • Cover open wounds with a clean, dry bandage until it scabs over or heals.
  • Treat fungal infections promptly.
  • See a doctor if you have a deep puncture wound or cut.
  • If you have an open cut or infection, avoid hot tubs, swimming pools, lakes, rivers, ponds, and the ocean.
  • Don't inject illegal drugs.
  • If overweight, try to lose weight safely.

If you have diabetes, check your feet and lower legs daily for any injuries or cuts. If you notice any, see your doctor.

Cellulitis Symptoms and Diagnosis

The symptoms of cellulitis are easy to notice.

Look for:

  • Red, swollen, painful, tender areas of the skin.
  • Itchy skin.
  • Skin that's warm or hot to the touch.
  • Smooth, shiny, or blistered skin.
  • Skin with tiny pits, like on an orange peel.
  • Pus coming from a wound.

If you have any of these symptoms, see your doctor.

Serious symptoms of cellulitis that need prompt treatment

Some symptoms are more serious and require urgent care.

If you have any of the following additional symptoms, go to the ER or an urgent care right away:

  • Fever or chills.
  • Feeling lightheaded or dizzy.
  • Shaking or trembling.
  • Feeling extremely tired or numb.
  • Muscle aches.
  • Black-colored skin near the infection.
  • Red streaks spreading out from the infected area.

Diagnosing cellulitis

Your doctor will diagnose cellulitis by looking at the affected area. Most people with mild cases don't need blood tests.

If your infection spreads quickly — or spreads to other parts of the body — you may need blood and imaging tests.

This will help your doctor learn what type of bacterial infection you have and how much is present.

Cellulitis Treatment

The goal of treating cellulitis is to cure the infection.

Doctors treat most cases with antibiotics. This is often a cream you put on your skin or a pill you swallow.

Some people may need an IV. This sends the medicine directly into your bloodstream and the site of infection.

Most people get better very quickly after they start taking antibiotics for their cellulitis.

Some people have allergies to certain types of antibiotics. Make sure your doctor knows about any drug allergies you may have.

What are the side effects of cellulitis treatment?

Common side effects of antibiotic treatment of cellulitis include:

  • Nausea or throwing up.
  • Diarrhea.
  • Not feeling hungry.
  • Discomfort in your belly.
  • Rash.
  • Dizziness.
  • Yeast infections.

Most people don't need to stay overnight in the hospital for cellulitis.

People who have a larger area of infection or a greater risk for other problems may need to stay in the hospital.

Contact the UPMC Center for Care of Infectious Diseases

To learn more about the UPMC Center for Care of Infectious Diseases or to make an appointment, call 412-647-7228 or 1-877-788-7228.