What Could Be The Brown Spots On Inner Thighs, Neck And Stomach?

my age is 20 my height is 5 foot 3 and weight is 120 and i have epilepsy. i have been getting brown spots on my inner thighs and neck and on my stomach for a few months now. they fade sometimes but stay visible but lately they have began to spread and are getting larger. i have no clue what it is.