white patches (lack of pigmentation)

hi friends,
one of my friends daughter s suffering from white patches on her face.c got it 4 years back. now c s 13 years old. DRS said that it s due to lack of pigmentation .and it will cure after her puberty. c tried so many alopathy doctors but the ans was the same. c even tried for homeopathy. ayurveda . but still no improvements.as it s in her cheek area it s very visible. can anybody who know the remedy pls help me with it.