White birthmarks on the arms of babies with abnormal pigment metabolism are as follows.
A baby with a white birthmark on the arm that has been present since birth and does not change after a certain period of enlargement needs to be promptly diagnosed differentially at the hospital. If it is determined that the white birthmark is due to an abnormal pigment metabolism disorder, observation and treatment may be an option. If it is not considered to be aesthetically pleasing or the patient has no personal need for treatment, it can be left untreated and will not affect normal life.