Why Did Laser Treatment Result in Demarcation Lines?

You are describing post inflammatory hyperpigmentation which is very common following ablative laser resurfacing of Asian skin.

The Erbium laser is less likely to cause hyperpigmentation than the CO2 but as you now know it can still happen.
The areas involved were treated deeper than the areas that do not have pigment.

This should resolve. Once your skin has healed, microdermabrasion, Hydroquinone and retin A can be used to reduce pigmentation. Occaisionally IPL or Photofacial is required.
Delayed long term hypopigmentation can occur when deep ablative laser peels are done on Asian skin. This should be less of a chance because the profractional is a fractional ablative laser.

Technically a demarcation line is usually used to refer to a junction between hypopigmented facial skin, which has been lasered and normal skin below the jawline which retains its normal color.


 

Patients of color need to be aware that they may respond with hypopigmentation or hyperpigmentation when being treated by resurfacing lasers. It is my opinion that pretreatment is necessary for darker pigmented patients using higher energy lasers.

It sounds like those three areas on your cheeks got more laser than they could handle. I would not necessarily lose hope, however, as there are many good treatments to subdue the extra pigmentation and should be started as soon as your skin has healed.

Your laser physician should be able to counsel you on your options. I would recommend a very good sunscreen and a skin lightener. I hope this resolves in your favor.

Dr. Shah

You are exactly right. It sounds like there was overlap of the treatment area and you may have been treated with densities and high as 30-40% in these hyperpigmented areas. We published a study about 1 year ago looking at fractional treatments in Asian skin and our conclusion was that the risk of hyperpigmentation was higher with increased density. Most likely, this will be temporary and could last a few weeks to a few months. This is why it is important to have your treatment done by a physician that is very experienced in these procedures. There are topical treatments that can help resolve this more quickly, and you should discuss these options with your doctor. Sunblock with zinc oxide and/or titanium is very important everyday to help resolve this and keep this from persisting longer. Take care, Dr. Groff