Is Large Purplish Scar After Burning The Skin Between Wrist And Elbow Serious?

I burned the inside of my arm quite ( between the wrist and the elbow) badly a few year ago, and I was left with a large purplish scar. Occasional I will get a scratch on it or hit it off something and it will swell up and bruise immediately. It becomes tender to the touch bit not painful, and I dont bruise so easily anywhere except this one area where I have the burn scar. I cant seem to find any reason as to why this might happen, and wondered if it was down to the scar tissue or if it might indicate something that should be looked at.