I had lots of SK's removed on my stomach, back and neck by my derm last summer using liquid nitrogen in a spray gun. The larger SK's are gone, however it left me with dark hyperpigmented spots, all on my stomach, even a year later! My back and neck seemed to heal fine. I still have lots more SK's appearing everwhere on my stomach, but they are very small, about the size of a pin head and smaller. What is the best way to get rid of so many small SK's without hyperpigmentation?