Can internal scar tissue in upper back muscles caused from overuse, cause prickling burning sensations when it starts to heal when massaged ?

Nerve pain: What you are describing is classic nerve pain. If you have not had back surgery the only other source of scar tissue would be from inflammation like arachnoiditis . Often the burning sensation is due to the release of inflammatory mediators as your trigger points are released thru massage. If it continues to be a problem see your physician.