Cellulitis is an infection of the skin and subcutaneous (under-the-skin) tissues that occurs when bacteria like Streptococcus and Staphylococcus enter the skin.

Where Do These Bacteria Enter the Body?

Although sometimes a portal of entry (where the bacteria enters the body) may not be obvious, bacteria are more likely to penetrate the skin in disrupted areas. These areas include:

  • Cuts
  • Ulcers
  • Dermatitis (inflamed skin)
  • Animal bites
  • Puncture wounds
  • Burns

Risk Factors

The risk of cellulitis may increase with

  • Dry or flaky skin
  • Skin conditions, such as eczema or shingles
  • Chronic tinea pedis (athlete’s foot), which causes scaling, erythema (red, patchy skin), and erosion of the skin between and underneath the toes
  • A compromised immune system or an immunosuppressive disease, such as diabetes
  • Circulatory issues like venous stasis, a condition causing slow blood flow in the veins that usually affects the legs
  • Lymphedema, a chronic swelling of arms or legs
  • Regular use of intravenous (IV) drugs
  • Contact sports or sharing exercise equipment


How is cellulitis transmitted?

Even though cellulitis is a bacterial infection, it usually does not transmit from person to person. A possible exception might be if a person with cellulitis has skin-to-skin contact with someone who has an open wound.

Will cellulitis go away on its own?

Less severe cases of cellulitis may resolve on their own; however, you may need prescription oral antibiotics. In most cases, cellulitis disappears a few days after starting on antibiotics. More severe cellulitis may require hospitalization and intravenous (IV) antibiotics.

Disclaimer: this article does not constitute or replace medical advice. If you have an emergency or a serious medical question, please contact a medical professional or call 911 immediately. To see our full medical disclaimer, visit our Terms of Use page.

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