There can be a number of causes of white spots (hypopigmentation) of the skin. Some of these do require medical evaluation or treatment. The doctors
who are qualified to discuss this issue with you include your primary care doctor
and your dermatologist
A very common cause of white spots (hypopigmentation) of the skin is post-inflammatory hypopigmentation. This is a loss of color in areas where there was a skin infection (such as acne) or trauma (such as scratches or burns). Color generally returns to these areas slowly as the skin heals.
Another very common cause is a fungal infection of the skin, such as tinea versicolor. This often shows up as subtle patchy areas of hypopigmentation, usually most prominent on the chest and back. Treatment of this condition can involve the use of either topical antifungal creams or oral antifungal medications as determined by your doctor.
Vitiligo is a progressive loss of skin color that has no cure and is of unknown cause. This is rarer than the other causes and usually results in much more profound loss of skin color.
As always, the diagnosis and the management of your particular condition will require a physical examination by your personal physician. Scheduling an office visit with your primary care doctor or your dermatologist might be indicated.