Vitiligo is a pigmentation disorder in which melanocytes (the cells that make pigment) in the skin are destroyed. As a result, white patches appear on the
skin in different parts of the
body. Diagnosis can be confirmed by external examination, blood tests to check skin cell count for melanocytes and biopsy of the skin patches. For the confirmation of diagnosisi would suggest you to consult a dermatologist.
I hope it helps.