Which Medication For Deworming Due To Anus Itching Is Recommended?

Hi! My daughter is 9yrs old and I want to perform deworming on her. What medicine should I give her? SHe is complaining of itchiness around her anus for two days.She hasn t loss her appetite but I want her to gain some weight because I see her too thin her age. If ever, this would be the first time we will be performing deworming on her. Lots of thanks and GOD bless!