What Causes Itchy Bump At The Site Of Piercing?

I had my cartlege pierced a few years a go and stuupidly got a cuff, I slept onit and it got sore I took it out and let it heal up and repiered it myself and an itchy bump formed around the site, so once again I too it out and doctored th bump. A couple years later I have now pierced it again and the same bum has came again.. is this hypertrophic scaring