Visit your doctor once. Because it may be due to some kind of deficiency. If that so then dont worry doctor will suggest you some drops of supplement to give. If doctor says than it is due to dryness and rough skin then try mamaearth body lotion. Because my son also got white spot like patches on his body due to dryness. I apply body lotion after bath daily to avoid all this. It is a natural product and has a mild fragrance and non sticky also. Keeps skin nourished and healthy.

Hi it might be just birthmark, when you visit her Paediatrician next time you can check.