We remind all of our patients of the need for strict sun avoidance for a minimum of four weeks before and after each treatment. The hyperpigmentation should fade in time but you may want to hasten things by using prescription-strength 4% hydroquinone cream. Also, if you are very sensitive to sunscreens as you say, you should try using a pure "physical" sunscreen that contains no chemicals. Physical sunscreens are opaque formulations that reflect and scatter ultraviolet and visible radiation. They contain two major sunblocks (titanium dioxide and zinc oxide) which are very effective because of their ability to scatter and absorb both UVA and UVB radiation. They are hypoallergenic and have a good safety profile. The major drawback in the past has been their physical appearance. Recently, micronized formulations (smaller particles) of these two ingredients have allowed for greater cosmetic acceptance. For a pure physical (chemical-free) sunblock, I recommend either Dermatologic Cosmetic Laboratories UVA/UVB Chemfree Superblock or SkinCeuticals Sheer Physical UV Defense.