Does the itch from hypertrophic scar caused by second degree burn ever go away? and what about the purple reddish color? if so, approx how long ?

Sometimes: It can take a year for the body to heal a second degree burn. The faster it heals the less likely a hypertrophic scar forms. If you have persistent vascular color and itching, additional scar treatment may help. Check in with your doctor to see what will help in your case.

It can over time: Try to get a steroid injection or Cordran Tape prescription. Laser can also help.