Suggest Treatment For Acrochordon

My daughter was born with what I was told a birthmark that looked like a rash but was gray. They told me it would go away when she got older. At 5 years old she started getting these growths that I thought were skin tags. I have now been doing some studying online and I have a suspicion that the rash is actually flat warts and the growths are filiform warts. How is that possible that she was born with them if I do not have genital warts?