What Is Cellulitis—And How Do You Get It?

Hives, rashes, acne—when something's up with your skin—you may start to run down the list of possible culprits. Maybe you ate something you were allergic to, spent too much time in the sun, or were super stressed last week. Sometimes symptoms are no big deal, and many times that's true. But cellulitis, a potentially serious infection that can cause the skin to become red, painful, and swollen, is not something you want to let go untreated for too long.

Here's what you need to know about cellulitis—so you can hopefully avoid ever experiencing it.

What Is Cellulitis?

"Cellulitis is a bacterial infection of the skin and subcutaneous tissues," Meghan Feely, MD, a board-certified dermatologist and spokesperson for the American Academy of Dermatology Association (AAD), told Health.

Cellulitis is considered common, with about 14.5 million cases diagnosed in the United States each year. Adults—who most commonly get cellulitis, especially in middle age or when they're older—often get the infection on their lower leg, while in children, it generally appears on the face and neck.

What Causes Cellulitis?

Cellulitis happens when bacteria get inside your body through something like a:

• Cut
• Scrape
• Burn
• Insect bite
• Open sore

It's even possible for another skin condition, such as athlete's foot or eczema, to compromise your skin's barrier and allow bacteria in, Dr. Meghan Feely said. Intravenous drug users can also develop cellulitis where the drug is injected, she added.

Bacteria usually cause cellulitis—streptococcus and staphylococcus—that already live on the skin without causing a problem, added Noelani Gonzalez, MD, cosmetic dermatologist at Mount Sinai West in New York City. However, in rarer cases, MRSA and other bacteria can cause cellulitis.

A skin injury usually won't cause cellulitis because the body's immune system destroys bacteria that travel through an opening in the skin. But in some cases, an infection will develop.

Who's More Prone To Getting Cellulitis?

While cellulitis can happen to anyone, some people are more likely to develop the skin infection. You're at an increased risk if you have any of the following:

• Diseases such as HIV or AIDS, long-term kidney or liver disease, lymphedema, and diabetes
• Skin conditions such as athlete's foot and eczema
• A previous case of cellulitis
• Poor circulation
• Frequent skin injuries

Other cellulitis risk factors include undergoing chemotherapy, taking corticosteroids, or having had recent surgery.

Is Cellulitis Contagious?

Cellulitis isn't usually spread from person to person, but if you have contact with someone with cellulitis, you should play it extra safe.

"Because cellulitis is caused by an infectious organism, people handling affected areas should use proper precautions when touching the area," said board-certified dermatologist and AAD spokesperson Lauren Ploch, MD. "However, being in the same room with someone suffering from cellulitis does not increase your risk of cellulitis."

Cellulitis Symptoms

You may feel ill even before seeing any signs of cellulitis on your skin. Non-skin-related signs of an infection include:

• Fever
• Chills
• Fatigue
• Pain, cold sweats, and nausea (if you have a more severe infection)

You will also see obvious signs of cellulitis on your skin. "The skin usually feels red and swollen," said Dr. Noelani Gonzalez, adding that it will be tender and warm to the touch.

When the infection is severe, you may have:

• Blisters on the red, swollen skin
• Swollen lymph nodes
• Streaks of red near the infected area
• A pus-filled bump near the infected area
• A rapid heart rate
• Low blood pressure
• Trouble concentrating

Cellulitis Treatments

A healthcare provider will usually diagnose cellulitis after examining the skin and asking you questions about your medical history, symptoms, and whether you'd had any skin injuries.

In most cases, an oral antibiotic can clear the infection after seven to 10 days. In severe cases or when the skin on the face is involved, cellulitis treatment may require IV antibiotics, which usually requires a hospital stay.

If an underlying condition caused the cellulitis, a healthcare provider might want to treat that condition.

Once you're on antibiotics, your healthcare provider will usually recommend proper wound care, rest, and elevating your legs to decrease swelling, said Dr. Meghan Feely.

How To Reduce Your Risk of Cellulitis

There are some steps that the AAD recommends you take to protect yourself (and your skin) from cellulitis.

Keep nails clean and manicured. Nails can be magnets for bacteria, and scratching yourself with dirty nails can hand-deliver bacteria into your skin. Washing your hands and keeping nails short and clean will help keep bacteria under control.

Treat wounds promptly. Open wounds and injured skin can be entryways for cellulitis-causing bacteria. If you injure your skin, wash the area with soap and water. Then apply an antibiotic ointment and cover the wound with a bandage. Be sure to change the bandage regularly.

Moisturize, moisturize, moisturize. "Keep your skin clean and moisturized," said Dr. Noelani Gonzalez. "Moisturizing will prevent cracks that might lead bacteria into your skin."

Manage any chronic conditions. You're more susceptible to cellulitis if you have an underlying health concern like diabetes. Managing these conditions can help prevent a possible skin infection. Consider making an appointment with a dermatologist to treat skin conditions that could lead to cellulitis, like athlete's foot or eczema.

When To Reach Out to a Healthcare Provider

It's crucial to contact a healthcare provider as soon as possible if you think you have cellulitis symptoms. "If not treated in time, cellulitis can be a life-threatening infection," said Dr. Noelani Gonzalez.

According to MedlinePlus, complications of cellulitis include:

• Blood infection
• Bone infection
• Inflammation of the heart or blood vessels
• Meningitis
• Shock
• Gangrene

According to Dr. Noelani Gonzalez, "prompt diagnosis and treatment with antibiotics is vital."