please help me

Dr,

I am experience hair loss and itchyness of the anal area and scalp.  I had a rash a few weeks ago all over my body that the doctors thought was dermititis and they also thought that of the anal itching but it hasnt gone away.  Im twenty years old and had really thick hair.  My hair come out just by simply touching it.  Hair specialists say that it should reverse itself and its just caused by stress.  However, I'm wondering if it is possible for me to have some sort of parisite? causing the anal itching .. that is so severe that i cant sleep and it does occur during the day.  that can also cause hair loss? please help me.