Can be hard to treat. Some people are prone to keloids, probably genetically determined. The problem is that if a doctor cuts out one keloid, another usually forms. Steroids are usually tried, such as an injection of kenalog (triamcinolone) into a keloid. Sometimes, steroids are injected into the site when a surgeon removes an existing keloid. Dermatologists and plastic surgeons with experience in keloids are the specialists to see.
Laser. A hypertrophic scar can also be treated with a non-ablative laser. I use the 1064 nm micro pulsed ndyag laser. The laser is non-ablative. It works by heating the skin and causing the scar to remodel with new finer collagen formation. Keloids can also be treated this way. Depending on the size of the keloid and whether other treatments have failed, surgery followed by radiation can be tried.