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 serious infection that occurs in the deep layers of your 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 can spread quickly. If you have cellulitis, it’s important to treat it right away with antibiotics. Though complications are considered 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 entered. Keep in mind that if you have dark skin, the redness may not be as obvious.
If left untreated, the affected area can spread. Chemotherapy can make you more likely to develop cellulitis because your weakened immune system makes it harder to fight off infections of all kinds.
If you experience any of these serious symptoms, seek medical attention immediately, as they may be life-threatening:
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 if you:
If you’ve had cellulitis in the past, you’re 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 you’ve had your lymph nodes removed, or your lymph nodes were damaged due to cancer treatment, you 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.
In order to diagnose cellulitis, your doctor 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 your doctor if your symptoms are not improving 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 your antibiotics as prescribed.
To decrease your chances of developing cellulitis:
If you have recurring cellulitis, your doctor may recommend a low dose of antibiotics taken over a longer period of time for prevention.
To help manage symptoms, you may: