This page was reviewed under our medical and editorial policy by
Maurie Markman, MD, President, Medicine & Science
This page was updated on March 2, 2022.
Cellulitis is a skin infection that affects about 14 million people in the United States each year. It's important for cancer patients to familiarize themselves with the symptoms of this condition so it can be detected early.
Cellulitis is a serious infection that occurs in the deep layers of the skin. It happens when bacteria (most often group A Streptococcus) enter the body through an opening in the skin, such as a surgical wound or chemotherapy injection site.
Cellulitis may spread quickly. If a patient has cellulitis, it’s important to treat it right away with antibiotics. Though complications are uncommon, the condition may lead to more serious infections of the:
In severe cases, it may cause necrotizing fasciitis, also known as a flesh-eating disease, which is a rare but very serious infection that destroys tissue and may lead to:
While cellulitis may develop anywhere in the body, it’s more likely to occur in the legs. Cellulitis causes the skin to become swollen and red in the area where the bacteria enter. Keep in mind that if the patient has dark skin, the redness may not be as obvious.
If left untreated, the affected area may spread. Chemotherapy may make the patient more likely to develop cellulitis because his or her weakened immune system makes it harder to fight off infections of all kinds.
If the patient experiences any of these serious symptoms, he or she should seek medical attention immediately, as they may be life-threatening:
Cellulitis is caused by bacteria entering a break in the skin, such as a cut, surgical wound, chemotherapy injection site or insect bite.
Though bacteria may live on top of the skin without incident, it may be more problematic when that bacteria gets into deeper layers of skin, potentially leading to cellulitis.
Any breaks in the skin that allow bacteria to enter increase the chances of developing cellulitis. Although cellulitis can affect anyone, it’s much more likely in patients who:
Patients who have had cellulitis in the past are at greater risk of developing it again.
Cancer patients who are undergoing chemotherapy or who are taking corticosteroids are also more vulnerable to cellulitis because the immune system is suppressed by these drugs.
If a patient had his or her lymph nodes removed, or the lymph nodes were damaged due to cancer treatment, he or she may develop a condition called lymphedema that makes cellulitis more likely. Lymphedema causes swelling in the arm or leg, stretching out the skin and making it more susceptible to cracking, thus providing a pathway for bacteria to enter.
To diagnose cellulitis, the care team may conduct a physical examination. In most cases, cellulitis can be diagnosed by its appearance alone.
Cellulitis may be treated with a course of antibiotics, usually for a week. It’s normal for symptoms to worsen over the first 48 hours then improve. Speak with the doctor if symptoms don't improve about two days after starting antibiotics.
Full recovery may be expected within seven to 10 days after starting the appropriate medication; be sure to finish all of the antibiotics as prescribed.
To help manage symptoms:
It may not always be possible to prevent cellulitis from occurring, but some steps may help decrease the chances of developing cellulitis:
If the patient has recurring cellulitis, the doctor may recommend a low dose of antibiotics taken over a longer period of time for prevention.