Cellulitis

What is cellulitis?

Cellulitis is a common bacterial skin infection that develops when bacteria enter the skin through a cut, scrape, insect bite or other break in the skin. The infection affects the deeper layers of the skin and surrounding tissue and can spread quickly without treatment.  

Most of the time, these minor injuries heal on their own. But sometimes, that opening in the skin creates an opportunity for germs to enter and infect the skin and the tissue under it.

Cellulitis is often mild and treatable, but sometimes it can lead to severe complications. Knowing the signs of infection and when to seek care can help you recover. Learn more about the symptoms of cellulitis, how it’s treated and steps you can take to lower your risk. 

What does cellulitis look like? 

Cellulitis usually starts as a red or darkened area of skin that feels warm and tender. The area may expand over hours or days. The skin can appear swollen, tight or shiny and may feel painful to the touch. 

On darker skin tones, cellulitis may look purple, gray or darker than the surrounding skin rather than bright red. 

If the area continues to spread or becomes very painful, seek medical care. 

What are the symptoms of cellulitis?

Cellulitis symptoms often develop quickly and may worsen within hours. Cellulitis can appear anywhere on the body but it’s most common on the legs, arms and face. 

Common symptoms of cellulitis include: 

• Redness or darkness. It’s normal to see redness or darkness when you injure your skin. With cellulitis, the red or dark area may spread out from the injury. 
• Swelling and warmth 
• Pain or tenderness
• Skin that looks stretched, shiny or tight
• Blisters

More serious symptoms may include: 

• General symptoms of infection such as fever, chills, dizziness, muscle aches or fatigue
• Pus, blisters, abscesses or drainage
• A rash that’s spreading quickly
• Brown to red streaks that extend out from the injured area
• Symptoms that get worse even though you’re treating them

If you notice these symptoms or the infection is near your eye or ear, seek medical attention right away. Early treatment can reduce your risk of complications.

What causes cellulitis?

Cellulitis develops when bacteria - most often group A Streptococcus (strep) or Staphylococcus aureus (staph) - enter the skin. These germs live on your skin and in your nose and mouth and can enter the skin if it’s injured.

A strain of bacteria called methicillin-resistant Staphylococcus aureus (MRSA) can cause more serious infections that are harder to treat. 

These germs can enter your skin anywhere there’s a break, such as:

• Cuts or scrapes
• Dry or flaky skin
• Wounds from surgery, piercings or tattoos
• Insect or animal bites
• Athlete’s foot, dermatitis, eczema, shingles, psoriasis or other skin conditions that cause cracks

Who is at risk for cellulitis?

Understanding risk factors can help you prevent cellulitis. You may be more likely to develop cellulitis if you have: 

• A weakened immune system from diabetes, cancer, HIV/AIDS, leukemia or certain medications 
• Poor circulation or edema (swelling) in the legs 
• Obesity
• A sedentary lifestyle
• Chronic skin conditions
• Previously had cellulitis

Is cellulitis contagious?

Cellulitis is not contagious. You cannot catch it from another person. It happens when bacteria enter through a break in your own skin.

How is cellulitis diagnosed?

To diagnose a case of cellulitis, your provider will perform a physical exam to check for signs of infection and symptoms of cellulitis. They may draw a line around the area to see if the redness or darkness is spreading.

They may recommend tests to confirm the diagnosis, including: 

• Bacterial culture to identify the type of bacteria causing the infection. Knowing the type of bacteria means you can get the right antibiotic to fight it.
• Blood tests to see if the infection has spread. 
• Imaging tests, such as ultrasound or MRI, to look for deeper infections.

Your provider may also check for other conditions, such as chronic (long-lasting) leg swelling or dermatitis, that could cause symptoms similar to cellulitis.

How is cellulitis treated?

A cellulitis infection won’t go away on its own and usually requires antibiotic treatment. Most cases respond well to medications like penicillin, dicloxacillin or cephalexin.

Tips for recovery:

• Take all prescribed antibiotics, even if you feel better
• Elevate the affected area to reduce swelling
• Apply a cool, damp cloth to the skin
• Use antibiotic ointment if recommended
• Cover wounds and keep them clean
• Take over-the-counter pain relievers, if needed

If the infection is more serious or caused by MRSA, you may need IV antibiotics in a hospital.

Contact your provider if symptoms don’t improve after a few days of treatment—you may need a different antibiotic or additional care.

How long does cellulitis last?

Most mild cases improve within 2 to 3 days after starting antibiotics. The redness and swelling may take 7 to 10 days to fully resolve. 

Severe infections may take longer and sometimes require hospital treatment.

If symptoms are not improving after 48 to 72 hours, contact your provider. 

What are the complications of cellulitis?

Getting treatment quickly and taking all of your medication as directed lowers your risk of complications. Untreated cellulitis can spread from the skin to the bloodstream and lymph nodes and become life-threatening. It can reach your muscles and bones.

Possible complications include: 

• Abscesses or pockets of pus that need to be drained 
• Bacteremia, sepsis or toxic shock syndrome (bloodstream infections) 
• Endocarditis (heart lining or valve infection)
• Osteomyelitis (bone infection)
• Damage to your lymphatic system and permanent swelling in the infected area 
• Necrotizing fasciitis, a rare, life-threatening infection that can destroy skin, muscle and fat

How to prevent cellulitis

You can lower your risk of cellulitis by protecting your skin and managing any underlying health conditions.

General tips to protect your skin:

• Clean cuts and scrapes right away with soap and water
• Apply ointment or cream and cover with a clean bandage
• Replace the bandage daily and keep the wound clean
• See your provider if you notice redness, discomfort or pus
• Moisturize dry skin to prevent cracks
• Treat conditions like athlete’s foot promptly
• Wear gloves when gardening or working outdoors
• Follow post-surgery wound care instructions
• Take medications as prescribed and attend regular checkups
• Talk to your provider about ways to prevent cellulitis if you've had it before

If you have diabetes or poor circulation, take extra steps to protect your skin:

• Inspect your feet every day for any cuts, scrapes or sores
• Moisturize your skin to prevent cracking or peeling
• Be gentle when trimming fingernails and toenails to avoid cuts
• Wear shoes and gloves that protect your feet and hands
• Treat any minor skin infection as soon as it starts

People who have had cellulitis before are at higher risk of getting it again, especially in the same area. Managing swelling, treating skin conditions promptly and protecting the skin can reduce recurrence. 

When should you see a doctor for cellulitis?

Get medical attention right away for: 

• Redness or darkness that is spreading quickly or swelling 
• High fever or chills 
• Skin that becomes numb, tingling or dark near the infection
• Symptoms that get worse after you start treatment

Why choose Banner Health for cellulitis care?

At Banner Health, we provide fast, expert care for cellulitis and other skin infections. Our specialists in infectious disease and wound care offer a full range of treatment options, including:

• Accurate diagnosis and testing
• Oral and intravenous (IV) antibiotics
• Advanced care for MRSA and severe infections
• Follow-up care to help prevent recurrence

If you notice symptoms of cellulitis or are recovering from a skin injury, don’t wait. Schedule an appointment today and get the care you need to heal.