Find possible causes of numbness or tingling in hands based on specific factors. Check one or more factors on this page that apply to your symptom. Numbness or tingling. 1  Affects both hands. 2  Affects one hand.  Is intermittent.
These cells produce melanin, the substance that gives skin its color. Skin with too much melanin is called hyperpigmented skin. Skin with too little melanin is called hypopigmented skin. Pale skin areas are due to too little melanin or underactive melanocytes. Darker areas of skin (or an area that tans more easily) occurs when you have more melanin or overactive melanocytes. Bronzing of the skin may sometimes be mistaken for a suntan.
Causes and Risk Factors. The light/white blotches of skin associated with vitiligo form when melanocytes fail to produce melanin. It is not known what causes melanocytes to die or stop producing melanin, but the following may play a role: 1  Autoimmune disease.2  Autoimmune diseases occur when the body mistakenly attacks and destroys its own cells.he light/white blotches of skin associated with vitiligo form when melanocytes fail to produce melanin. It is not known what causes melanocytes to die or stop producing melanin, but the following may play a role: 1  Autoimmune disease.