Hi. Greetings. You'll need to send me snaps of these spots so that some form of a diagnosis could be made. Meanwhile you must start using a good sunscreen and repeat application of the same every the hours in day time if you ate involved in out door work. Other forms of treatment for marks in the form of creams, lasers etc too are there.
Alternatively you could meet a dermatologist near you. Hope this helps. Let me know if you need any further assistance in this regard. Warm regards.