When a person has necrotizing fasciitis, they may experience severe pain that worsens with time and experience flu-like symptoms. They may also become dehydrated. A person with these symptoms should seek immediate medical attention. Without prompt treatment, the wound will swell and may become purple. Later, blisters will develop that ooze dark fluid. This is a sign of dying tissue or necrosis. The infection will then spread beyond the initial wound site and become life threatening.