Vitamin E or Mederma (suggested by my ENT/plastic surgeon)
Yup
I blew myself up as a teenager playing with bombs

I had 3rd and 2nd degree burns on my face neck chest upper arms.
The blast was so hot my glasses melted.
After I got out of hospital I started using vitamin E and tissue oil, it made a big difference.
If the scar is small they sell special plasters that you use for 6 weeks that is brilliant at getting rid of visible scar tissue