An addition to the answer by Dr. Shterjovska:

A scar from herpes blister might look very similar to a scar from chickenpox. If you have ever seen one, you would how they look like. The scar is usually slightly under the surface of the skin and can be darker than the surrounding skin. The dimensions vary but are usually the same size of the blister that caused it. The itching can occur in both ingrown hair and herpes blister. However, genital herpes usually appears in clusters.
In the end, a visual examination by a doctor might help you solve this problem. If the scar causes no additional symptoms, then you might leave it as well; because both conditions that are suspected as possible cause have ceased to exist a long time ago.

Hope to have your problem solved soon.