Birthmark is an indelible mark produced by the accumulation of body pigment, which can be regarded as a skin disease. As far as the current medical level is concerned, it is not an incurable disease. Some people's birthmarks will be accompanied by doctors and do not need treatment. Except a little ugly, it won't affect personal life. But some birthmarks are very dangerous. For example, vascular birthmarks may be a precursor to hemangioma.
Nowadays, many dermatology hospitals or dermatology departments of top three hospitals can almost treat birthmarks. It won't cost too much. It is best to take your child to a dermatologist for diagnosis. Don't trust those folk remedies. After all, the child is too young to go to the hospital.