I know its been a while since the post but if its not a fungus and its not vitiligo its most DEFINATELY "Idiopathic Guttate Hypomelanosis"...this is/are: small white spots that appear mostly on the shins and arms but also any area that is exposed to sun. There is a decrease in melanocytes in the skin in these small areas 2mm-5mm in size and they are a normal part of the aging process and are not an illness or detrimental to your health. If the worst that is suffered is vanity driven self dislike then I suggest a course of counselling so that you learn to love and like your body and yourself as you are..a beautiful being living on a beautiful planet. I have these and they do not affect how others see me or treat me, no-one even notices unless it is pointed out and then WOW GUESS WHAT..they often have them too! Studies in the area have progressed so that skin re-pigmentation COULD be a viable treatment but to date there is no cure and specific causes are still pretty much aging and sun damage