Necrotizing soft tissue infection is a rare but very severe type of bacterial infection that can destroy the muscles, skin, and underlying tissue. Necrotizing refers to something that causes tissue death.

Many different types of bacteria can cause this type of infection. A very severe and usually deadly form of necrotizing soft tissue infection is due to Streptococcus pyogenes, which is sometimes called "flesh-eating bacteria."

Necrotizing soft tissue infection develops when the bacteria enters the body, usually through a minor cut or scrape. The bacteria begins to grow and release harmful substances (toxins) that:

• Directly kill tissue
• Interfere with the blood flow to the tissue
• Break down materials in the tissue, which rapidly spreads the bacteria, leading to widespread effects such as shock