Greetings, Your concern is very genuine. Thanks for the query. Nevus of Ota is a difficult condition to treat, but promising results can be achieved. The first step is to do a skin biopsy to determine the exact location of the nevus among various layers of the skin so that depth of laser machine can be decided. Targeting through a single agent may not always be fruitful. Meet a qualified Dermatologist to learn more about the diagnosis and treatment options. Combination of different therapeutic agents is always beneficial. Revlite i.e. Q-switched Nd YAG laser has been available for stubborn pigmentation and can also be combined with fractional CO2 laser (fraxel) if needed. You can read about this machines from online sources.