Dear Madam, Thank you for your question here at HealthCareMagic. I am a dermatology fellow, read your question and understand your concerns... What you are describing as black splotches that will not go away on your neck and under your breasts is quite vague and can relate to a wide number of conditions or skin lesions. I will try to guide you through some of the most probable causes of you black spots. For more information please upload a good quality picture so we can take a look together. 1. Cafe au lait spots 2. Mongolian spots 5. Solar lentigo (most probable cause) 6.Tinea versicolor (lab exam or lamp exam needed) The order is not the frequency order just what cam first in my mind. As for the treatment part and how to get rid of them, we need more info on your lesions as each has it s own specific treatment. What I can encourage you to do is either upload a clear picture of your lesions here at HealthCareMagic or pay your Dermatologist a visit because from your description I can not recommend any treatment nor place a clear diagnosis. Do not hesitate to ask if you have further questions. Best Regards,