Why do you have patchy skin on areas of your back that are not as tanned as the surrounding area and speckles of lighter skin spots on your stomach which are highlighted more when you sunbathe?

I have this as well!!! Apparently its due to excessive use of sunbeds or natural sun without enough protection. I found that after not being exposed to strong sun or sunbeds it cleared up and my skin looked normal again, though after holidays this year its back. So I therefore blame it on the sun!! Hope this helps.