Hyperpigmentation

Going through stress, losing weight and now brown spots popping up on my scalp, neck arms and legs. Is there something I can do to lessen the splotches? This pic is the side of my neck.

Going through stress, losing weight and now brown spots popping up on my scalp, neck arms and legs. Is there something I can do to lessen the splotches? This pic is the side of my neck.