Hello,
Your son’s symptoms are suggestive of post inflammatory hypopigmentation which is very common after laser treatment. The pigment-producing cells (melanocytes) are damaged or destroyed in the healing process of inflammation.
There is very little that can be done in post inflammatory hypopigmentation although with sun exposure the white areas should eventually repigment. If the symptoms persist then please consult a dermatologist.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your dermatologist. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
If you just want something to add some color, you could try self tanning lotions. But, if it were my child I might take him to another dermatologist for a second opinion. If you are still in the military, I know how difficult "on post or Tri-care" providers can be sometimes. Just be persistent and make demands not requests, it is their job to care of you properly!