A skin infection with a bruise

Infection can develop after an injury or wound to the skin or mucous membranes (such as the inside of the nose or mouth), a bite or sting, a tattoo or piercing, or other skin problems. Signs of infection may include:

• Increased pain, swelling, redness, or warmth around the affected area.
• Red streaks extending away from the affected area.
• Drainage of pus from the area.
• Swollen lymph nodes in the neck, armpit, or groin.
• Fever or chills.

Bruises usually do not become infected unless the skin was cut, punctured, or scraped. Most wounds will not become infected if they are properly cleaned and cared for. If you have a cut, puncture, or scrape, see the Home Treatment section of the topics Cuts, Puncture Wounds, or Scrapes, and follow the steps for cleaning and caring for a wound to reduce your risk of infection.

It is important to watch for a skin infection during the healing process. Wound infections are more likely to develop if:

• Blood collects in the wound (wound hematoma).
• Dirt or objects, such as splinters, are left in the wound.
• The wound is in the genital or anal area, in a skin fold, or between the toes.

Prompt treatment of a wound infection can prevent serious complications.