Helooo M Nuzhat From Pakistan I Want To Ask U

helooo m nuzhat from pakistan i want to ask u that my son is only 10 months old and a white spot is appear in lower lip and no other spot on his body dr told me its phulbari m sooo much worrid i have no any family history of this disease plz tell me that is any treatment of this disease to stop it ? is this patch spread more or not ?