There could be a number of different reasons for your itch, and I suggest you see a dermatologist
for an examination. You are describing your itch as affecting basically your entire organ, your skin. The possible causes for generalized itching includes infection, inflammation, and break down of the skin's natural barrier. Organisms such as mites could be passed from person to person and is contagious.The common term is scabies. If you had skin contact in crowded places, you have a higher chance of getting it. It can cause generalized itching and often you can see skin burrows between your fingers. Another possibility include an allergic response from the number of different oils, lotions, and soaps you are using for your skin. These products, especially bath/shower soaps, can take away the natural oils that protect your skin from drying out. You described that you have a dry patch which could be a sign of dry skin. You should limit the number of showers you take to once a day and use warm water instead of hot water, as hot water can further deplete your skin of it's natural oils. Though these only cover some of the possibilities that can cause generalized itching, you should see a dermatologist so he/she can examine your skin.