I have a sudden, meaning just appeared today, yet persistent, as it s lasted for hours now, appearance of pigmentation? (Little brown dots) that have appeared on the skin of my upper left arm and spread onto my shoulder up to my neck. They are nowhere else on my body. They are not raised, do not itch, and, other than some persistent tiredness, I m not experiencing any other symptoms. I hv hypothyroidism, am overweight, but quite healthy, I.e., cholesterol low, pressure low average, T levels normal, periods normal, mammogram clear. I m 47 years old. Should I be concerned?