Hello, welcome Becker nevus is a birth marks. It has lot of hair too. 1. As such there is no treatment except lasers. as you said you have taken laser but which laser?? and what was wavelength of laser? these all point are very important to get good results 2. You should take q switch ND YAG laser with deeper wave length. 1064 wave length would be best one 3. Quality of q switch machine is also important. Good company give better results 4. 6-8 sitting would be required some time it could be more than 10 sitting too to get the results 5. There is possibilities that it wont go 100%. Result could be achieved up to 70-80 % max.