It seems that you are having skin disease related with mind.
You are having crawling sensation.
It is found in delusion of parasitosis.
It is hypochondrial psychosis
Thyroid dysfunctions and vitamin B 12 deficiency shoud be ruled out by blood tests.
Antipsychotics like pimozide or olanzapine
may be taken under medical supervision.
Local calamine lotion or antibiotic cream may be applied.Consult dermatologist
and also take advice of psychiatrist
I hope you got my answer.
Dr. Ilyas Patel MD