I had read this article the other day by a dermatologist consulting at a second opinion site. He says that Itchy skin (pruritus) can be caused by a number of factors, however in most of the cases it is a local skin irritation or a disorder of the nervous system. Itching sensations can be experienced as skin irritations, crawling skin, inflammation, rashes or minor irritations. Common causes of itchy skin are environmental allergies, dermatitis, skin rashes, bacterial or viral infection, even jaundice. Since your case seems rather severe, you better consult a dermatologist.