A pic would be more helpful in concluding as there are different types and shapes /sizes of white patches possible.
Often it may be related to some minor gene related issue. One may ask for a chromosomal study or skin biopsy
can be birth mark. Often there is no permanent cure with medicines, but plastic surgeries at later age, laser therapy
and tattoing the skin patch, UV therapy, herbal therapy
have promising effects when child grows old.
Treatment is often lasting for months, frustrating and should be tried under expert dermatologists guidance. As nothing is urgent, currently you should wait and watch.
yes newborns can have it. It is cosmetically curable in good number of cases.
I hope that answers your query. Please accept the answer.