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Cellulitis: Overview

What is cellulitis?

Cellulitis is a common and potentially serious infection caused by bacteria. The bacteria infect the deep layers of skin and tissue beneath the skin.

The first sign of cellulitis is usually red and swollen skin. When you touch the infected area, it often feels warm and tender.

This infection can show up anywhere on the skin. Adults often get it in a lower leg. In children, cellulitis tends to appear on the face or neck.

Cellulitis on the lower leg

Cellulitis causes redness, which may cover the entire area of be blotchy, as shown here.

Cellulitis on the lower leg

While cellulitis often develops in a leg, redness and swelling in both legs usually means you have another condition. You could have stasis dermatitis or contact dermatitis.

If you think you have cellulitis, you should get immediate medical care. Caught early and treated, cellulitis usually clears completely without causing any long-term problems.

Without treatment, the infection can spread quickly. The bacteria may travel to lymph nodes and into the bloodstream. This can lead to a blood infection or permanently damage lymph vessels, which are part of your immune system. Other complications can also develop.

When treated before complications occur, most people recover fully. Caught early, your doctor can treat it with oral (take by mouth) antibiotics and good wound care.

After starting treatment for cellulitis, you should notice improvement in 24 to 48 hours. If you don’t, call your doctor’s office. Severe cellulitis may require you to be treated in a hospital.

Image used with permission of Journal of the American Academy of Dermatology: J Am Acad Dermatol 2012; 67:163.e1-12

Al-Niaimi F, Neil Cox N. “Cellulitis and lymphedema: A vicious cycle.” J of Lymphoedema.” 2009;4(2):38-42.

Hirschmann, JV and Raugi GJ. “Lower limb cellulitis and its mimics: Part I. Lower limb cellulitis.” J Am Acad Dermatol 2012;67:163.e1-12.

Raff AB, Kroshinsky D. “Cellulitis: A review.” JAMA. 2016;316(3):325-337.