Dear Mr. Ashish,
Vitiligo may have been triggered by a stressful event eg. malaria as in your friend and should not be considered as a side effect of the drug per se. Moreover, there are many treatments available and it is important to start treatment as early as possible as the chances of recovery as well as prevention of spread are more. Since the spots are on the fingers and elbows, she should avoid trauma and exposure to chemicals, especially phenol based ones. Though there are chances that children of these parents may get vitiligo, they are small and genetic studies are underway.

Dear Sir,
your friend is suffering from a disease called 'Vitiligo' . It is a depigmenting disorder of skin where the pigment producing cells of the body are destroyed by the body's own antibodies. A host of therapy is now available from medical therapy, phototherapy, skin grafting, melanocyte culture, lasers to cosmetic camoflouge making a once dreaded stigmata associated disease almost curable. Consult a dermatologist who can tailor make your therapy to suite your skin needs according to your site, extent, and other parameters like diabetes, thyroid disorders etc.
yes it is hereditary at times.
with proper treatment they say "the light in the patient appears as the lightness in thier skin disappears.
santanu
MD, DNB( Dermatology)