Hi, for months now, there have been dark brown patches around the front of my ankle (where you usually have your shoe laces start, just before it, at the base where the shin ends and foot starts). It does not itch, but the patches are substantial. Stark contrast to the rest of my skin. I don't have any itching in the area so not sure why the patch isn't going. I'm concerned if it's going to spread. What could it be? I am a software engineer, and am slightly overweight (166cm height, weight 75kg). Could it be due to some sort of weight condition, or blood sugar (I am not diabetic, but family history has diabetes).. or varicose veins?