Increase in Invasive Group A Strep Infections, 2022–2023
CDC is looking into an increase in invasive group A strep (iGAS) infections among children in the United States. iGAS infections include necrotizing fasciitis and streptococcal toxic shock syndrome.
Cellulitis: All You Need to Know
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.
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).
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; it is not contagious.
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.
Seek medical attention immediately if the red area of the skin spreads quickly or you develop a fever or chills.
Anyone can get cellulitis, but some factors can increase the risk of getting this infection.
Infections or injuries that break skin
The following are risk factors because they allow bacteria to get through the skin:
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.
Other health factors
Other factors that increase someone’s risk for cellulitis include:
- Being overweight
- Having limbs (feet, legs, hands, and arms) that 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 typically diagnose cellulitis by looking at the affected skin during a physical examination. Blood or other lab tests are usually not needed.
Doctors treat cellulitis with antibiotics.
- Oral antibiotics (medicine taken by mouth) — Used to treat most cellulitis infections
- Intravenous (IV) antibiotics (medicine given directly into a vein) — Used to treat more serious infections
If the infection is in the arm or leg, then keeping that limb elevated can help decrease swelling and speed up recovery.
Complications from cellulitis are uncommon but can include serious infections:
- Bacteremia (blood infection)
- Suppurative arthritis (bacterial infection in a joint)
- Osteomyelitis (bone infection)
- Endocarditis (swelling of the inner lining of the chambers of the heart and heart valves)
Cellulitis can cause thrombophlebitis (swelling in a vein due to a blood clot).
People can get cellulitis more than once. Having cellulitis does not protect someone from getting it again in the future. There are no vaccines to prevent group A strep infections, but there are things you can do to help protect yourself and others.
To help prevent group A step infections, you should:
- Wash your hands often
- Clean and care for wounds
Clean and care for wounds
See a doctor
See a doctor for puncture and other deep or serious wounds.
If you have an open wound or skin infection, avoid spending time in:
- Hot tubs
- Swimming pools
- Natural bodies of water (e.g., lakes, rivers, oceans)
People with diabetes should check their feet daily, looking for injuries or signs of infection.