Will Laser Resurfacing Make PIH Worse from Prior Laser Resurfacing?

Post laser hyperpigmentation is a common problem following laser resurfacing and is not necessarily related to the "burn" that you experienced. That said, the greater the injury the greater the degree of PIH. Laser resurfacing is just that, in that is smooths out the skin and has the additional benefit of evening out darker skin tones. It is not specifically designed to treat browns, though, but more to smooth out wrinkles. There are different opinions in the industry regarding whether to pre-treat the skin with hydroquinone or not before laser resurfacing. Not pre-treating risks increasing the possibility of PIH. The good news is that it typically responds to topicals and bleaching creams.I would continue to use your topicals and "bleaching cream" and give it a good 3 to 6 months before trying another light source therapy if at all. It takes time for these to work, especially if you are young or have any degree of melasma or of darker skin ethnicity.  

Please consult a board certified dermatologist to treat your postinflammatory hyperpigmentation.  Laser is not recommended.  You must avoid the sun. Fading creams and light chemical peels may be appropriate.

Post-inflammatory pigmentation is the term given to darkening of the skin after injury or inflammation whether intentional (laser) or unintentional (road rash).  It is more common in people with darker skin types.  This type of pigment sits deeper in the skin and is more difficult to treat.  The most helpful thing you can do at this point is to apply a zinc containing sunscreen (SPF > 30) daily and every 2 hours when outdoors, continue the bleaching cream nightly (I prescribe hydroquinone 4-7% combined with tretinoin .025%), and wait about 3 months to assess your progress.  As another doc pointed out, light chemical peels with salicylic acid or Jessner's can be helpful during this period every 2 weeks or so for a series of about 5 peels.  While additional laser including the fraxel restore dual or intense pulsed light devices may help, these would not be my first line treatment.  Given your propensity to hyper pigment, I recommend lower-than-average settings (which equals more treatments) for any future laser treatments.