Skin pigment change. Pigment changes can be caused by sun damage, certain plants and fruits when touched to the skin, scarring, trauma from lasers, peels, etc.
Need expert opinions about skin "pigment" changes to lighter tone temporarily in certain spots on arms and legs only? What could be the cause?
Temporary, permanent. If these spots are permanent and and not temporary you may have something called idiopathic hypomelanosis. They are more prominent when you are tan and are a sign of sun damage. I am not sure that this is the right diagnosis so you might want to see a dermatologist.
Genes/Sun/Hormones. And a host of other factors.
Multiple factors. There are many causes for pigment change, hormone, inflammation, etc.\ proper diagnosis of the cause[s] is necessary before instituting treatment.
Yes it may. These conditions are commonly referred to as melas a or chloasma.
It can. Your dermatologist or plastic surgeon can help you plan a treatment regimen.