Q: Can hypopigmentation on the arms that has been present for about 10 years still leave one’s skin?
A: Hypopigmentation is the loss of color in the skin, and the contrast of the light spots is especially more noticeable after months in the summer sun, when the rest of your skin may be darker. If your pale spots have not changed in size over 10 years and are small, it is probably a common and benign condition that is actually a type of scarring, and which is not likely to disappear without treatment.
If this is worrisome to you or if you have observed changes in the affected areas, such as an increase in the size or number of spots or the development of a fine scale or dryness over the spots, you should see a dermatologist to make sure there is no underlying disease.
Because you have had the condition for a decade with no changes, it is not likely caused by vitiligo, which is typically a progressive and dramatic skin disease. Actinic keratoses can produce light spots on the arms and are persistent but slow growing and should be treated in order to prevent more serious disease.
Although it is very difficult to bring color back into skin affected by hypopigmentation, there are several laser therapies and topical therapies that can help to return the skin to its normal color. Such therapies also treat the surrounding skin in order to fade any increase in skin color due to sun damage, as sun exposure on the arms is extremely common. The goal is to blend hypopigmented spots into the surrounding skin and to soften the contrast between the lighter and darker skin.