When my son was going through puberty he had a lot of trouble with the control of his CAH. He was put on a very high dose of dex which caused acne (amongst other side effects) I took him to see a dermatologist who said it was a steroid induced type of acne caused by the dex.  I do not mean to add to your worries but acne can scar, although not all types do, it  could be worth seeing a dermatologist as well.  My advice is to get a second opinion!