Cellulitis: All You Need to Know

Puncture Wound on Human Foot with Infection

Cellulitis is a common bacterial skin infection that causes redness, swelling, and pain in the infected area of the skin. If untreated, it can spread and cause serious health problems. Good wound care and hygiene are important for preventing cellulitis.

Many bacteria can cause cellulitis

Different types of bacteria can cause cellulitis, which is an infection of the deeper layers of the skin. This page focuses on one of the most common causes of cellulitis: group A Streptococcus (group A strep).

How people get cellulitis

For many people who get cellulitis, experts do not know how the bacteria get into the body. Sometimes the bacteria get into the body through openings in the skin, like an injury or surgical wound. In general, people cannot catch cellulitis from someone else.

Signs and symptoms

In general, cellulitis appears as a red, swollen, and painful area of skin that is warm and tender to the touch. The skin may look pitted, like the peel of an orange, or blisters may appear on the affected skin. Some people may also develop fever and chills. Cellulitis can appear anywhere on the body, but it is most common on the feet and legs.

See a doctor if you have symptoms of cellulitis.

Seek medical attention immediately if the red area of the skin spreads quickly or you develop a fever or chills.

Breaks in the skin allow bacteria to enter

Anyone can get cellulitis, but some factors can increase the risk of getting this infection. The following are risk factors because they allow bacteria to get through the skin:

  • Injuries that cause a break in the skin (like cuts, ulcers, bites, puncture wounds, tattoos, piercings)
  • Chronic skin conditions (like athlete’s foot and eczema)
  • Chickenpox and shingles
  • Injection drug use

Other factors that increase someone’s risk for cellulitis include:

  • Being overweight
  • Having limbs (feet, legs, hands, and arms) stay swollen (chronic edema), including swelling due to
    • Lymphedema (problems with the lymphatic system so it does not drain the way it should); the lymphatic system is a part of the body’s immune system that helps move fluid that contains infection-fighting cells throughout the body
    • Coronary artery bypass grafting (having a healthy vein removed from the leg and connected to the coronary artery to improve blood flow to the heart)

Doctors diagnose cellulitis by how it looks

Doctors typically diagnose cellulitis by doing a physical examination and looking at the affected skin. Blood or other lab tests are usually not needed.

Antibiotics are needed

Cellulitis is treated with antibiotics. Most cellulitis infections can be treated with oral antibiotics (taken by mouth). More serious infections may need to be treated in the hospital with intravenous (IV) antibiotics, which are given directly into a vein.

If the infection is in the arm or leg, then keeping that limb elevated can help decrease swelling and speed up recovery.

Complications are uncommon, but can be serious

Complications from cellulitis are uncommon but can include serious infections in the following locations:

  • Bacteremia (blood)
  • Suppurative arthritis (joints)
  • Osteomyelitis (bone)
  • Endocarditis (Lining of the chambers of the heart and heart valves)

Cellulitis can cause thrombophlebitis (vein swelling if blood clots form close to the skin).

Learn about necrotizing fasciitis.

Protect yourself and others

People can get cellulitis more than once. Having cellulitis does not protect someone from getting it again in the future. While there is no vaccine to prevent cellulitis or group A strep infections in general, there are things you can do to protect yourself and others.

Good wound care

A small cut on the arm has been washed to clean the wound.

Clean all minor injuries that break the skin with soap and water.

Good wound care is the best way to prevent bacterial skin infections, including cellulitis. To prevent group A strep infections, you should:

  • Clean all minor cuts and injuries that break the skin (like blisters and scrapes) with soap and water.
  • Clean and cover draining or open wounds with clean, dry bandages until they heal.
  • See a doctor for puncture and other deep or serious wounds.
  • If you have an open wound or active infection, avoid spending time in:
    • Hot tubs
    • Swimming pools
    • Natural bodies of water (e.g., lakes, rivers, oceans)
  • Wash hands often with soap and water or use an alcohol-based hand rub if washing is not possible.

People who have had multiple cellulitis infections below the knee should be checked for fungal infections, such as athlete’s foot. These infections should be treated since they can cause breaks in the skin that can lead to cellulitis.

People with diabetes should check their feet daily, looking for injuries or signs of infection.