I am going to try my best to describe what is happening to me quite often. It has been my thighs every time. I will feel an irritation, a sudden itch so I begin to scratch. It gets so itchy that my scratching does not seem to help and I pinch my skin because it is itchy but also stings a little.after about ten minutes somethind deeper maybe tissue or muscle feels sore and I get very large bruises, which have been so bad they covered the entire outer part of my thigh. It happens on both legs in different locations simultaneously..... sometimes going up towards my hips. I asked a doctor and showed him his the first time it happened in may 2011, and he was puzzled but did not think I should worry. I stay pretty healthy, not sick often but this has happened about 4-5 times since then.