Can laser treatment cause blemishes on the chest area while the skin is recovering?

Hello,With a photo, we can assume that you are observing brown or persistent red blemishes.  This is a very common side effect during the healing process and is referred to as, "post inflammatory hyperpigmentation" (aka:  PIH).  There are methods to improve on brown discoloration if this is not improving after several weeks.  If the area is pink/red, then time and gentle skin care will offer improvement.  If this does not improve over time, then considering a pulsed dye laser will help.Generally, blemishes (PIH) that has not improved after six months is considered permanent and will benefit from treatment options.  In the meantime, please practice very gentle skin care with gentle products.  Diligent sun protection at all times is recommended.

Great question! It's very hard to give you a best response without seeing a picture (or better yet, you in person!) and knowing your settings. If you haven't done so, be sure to contact your treating office.
Chest does take much longer to heal than face, with its thinner skin, reduced blood supply and less healing stem cells. That being said, the combination of bbl and erbium is a great combination and one of our most popular treatments. 
Another reason to contact your office is that blemishes could simply be healing, or could represent clogged pores or a contact dermatitis which would benefit from treatment.