How can I get rid of the scratch scar by nail which is on my inside forearm? (Photo)

The treatment of scars on the face and body follows a protocol-based approach in our office. We start by characterizing the scars in terms of redness, atrophy, hypertrophy, size, volumetric biometrics, and color hyperpigmentation and then devise a customized protocol for you. 
Our Hidef scar protocol uses micro fractional and fractional RF, fractional laser, sublative RF, vbeam therapy, injection based IIT, and scar modulation. Scars that exhibit growth should begin treatment with Plato's Scar Serum twice daily followed by Melarase AM and Melarase PM for dark and discolored scars. 
Best, 
Dr. Karamanoukian
Realself100 Surgeon

These spots can be improved with a combination of Cosmelan, lasers, Aerolase, microneedling/prp, skin lightening, peels, and skin care. Sun protection is essential. I recommend getting a formal evaluation with a scarring expert. Best, Dr. Emer

Scars continue to mature and improve over a year. You can continue treating your scar with various methods. Topical options include silicone-based strips or gels. Most importantly, keep them out of the sun. Overtime, your scar should continue to improve on its own. For  young,old, or deeper scars that have plateaued in their improvement, microneedling with or without PRP, fractionated laser, and radiofrequency make microscopic holes in the scar to stimulate your body to remodel and fill in the scar with new collagen. I especially like a combination of a chemical peel for the hyperpigmentation, microneedling with PRP for texture and collagen building, and PIXEL fractionated laser or RF to resurface and build even more collagen.  For large or more severe irregularities, a scar revision or re-excision may swap out your old scar for a less noticeable one in a single procedure. Not everyone is a candidate for all the treatment options however as certain skin types can get worse from certain treatments. For the safest treatment plan, it is important to visit an expert for an in-person examination. Hope this helps!
Johnson C. Lee, MD 
Board-Certified Plastic Surgeon