In your case, you should analyze it in detail. Several issues that need to be considered include: the location of the scar, the size of the scar area, and the situation of scar hyperplasia.

Because it's been 18 years since your burn, the scar suppressants are useless to you now. There are two ways to consider:

1. Physical methods, such as grinding or laser. These two methods are effective for scars with small area and inconspicuous hyperplasia, and are recommended for scars in special parts such as face.

2. Surgical treatment, including skin grafting and skin flap. If your scar area is large, you need to consider skin grafting, but skin grafting also has disadvantages, such as donor scar, which is not suitable for face. If your scar is small, and it is in the trunk, limbs and other parts, you can consider directly removing it and repairing it with adjacent flaps. The method of dilator can also be considered for the scar of neck or mandible, but the course of treatment is long and painful.

3. Another method worth considering is injection of glucocorticoid for scars with small area and inconspicuous hyperplasia.

These are just some of the current treatments for scars. The specific one suits you and needs you to go to the hospital. Your attending doctor will make a treatment plan according to your situation. It should be noted that scar treatment is a difficult problem in the medical field at present, and most methods can only be improved, but there is no good radical cure.