Vitiligo is more noticeable in darker skinned people because of the contrast of white patches against dark skin.
There is a sudden or gradual appearance of flat areas of normal-feeling skin with complete pigment loss. Lesions appear as flat areas with no pigment and with a darker border. The edges are sharply defined but irregular.
Frequently affected areas are the face, elbows and knees, hands and feet, and genitalia.
Examination is usually sufficient to confirm the diagnosis. In some cases, a skin biopsy may be needed to rule out other causes of pigment loss. Your doctor may also perform blood tests to check the levels of thyroid or other hormones, and vitamin B12 levels.