Hello. The white patches you describe are sometimes called 
leucoderma, another term for 
vitiligo. These skin changes result from an autoimmune disorder in which the immune system targets melanocytes, cells that produce the pigment (melanin) that colors skin.
While it can be emotionally distressing, vitiligo doesn’t present a threat to general health, because the disease process remains on the surface of the body. Conventional treatment focuses on evening out skin color, usually with 
steroid creams or with the drug 
psoralen (which reacts with ultraviolet light so that skin darkens). For most patients, this involves taking psoralen as a pill or having it applied to affected areas, then exposing the skin to PUVA (ultraviolet light) in the doctor’s office. PUVA is said to be up to 85% effective in more than 70% of patients with vitiligo of the head, neck, upper arms, legs, and trunk. It can take months to get good results though, and maintenance treatments are needed to keep the condition in check.
Before trying it, you might consult a hypnotherapist. Skin conditions respond well to 
hypnosis, and there are reports that it can lead to repigmentation in some cases.
You also might consider 
ginkgo biloba.
Meet a 
dermatologist and get appropriate treatment.
With regards- Dr Sanjay Kini