Hypopigmentation, or decreased pigment in a certain area, is really tough for us. If it's secondary to a condition like vitiligo, there are specific treatments for returning pigment to that area. However, if it's hypopigmentation from post-inflammatory, or inflamed skin, it has the possibility to hypo-pigment after the inflammation resolves.
This issue is really a challenge for us as dermatologists. Usually, just tincture of time, or letting pigment homogenize from the surrounding areas is our best option for re-pigmentation in that area. Lasers don't work well for hypopigmentation, but they can be a nice viable option for hyperpigmentation.