The Earth's Crust is like the skin of an apple. It is very thin in comparison to the other three layers. The crust is only about 3-5 miles (8 kilometers) thick under the oceans(oceanic crust) and about 25 miles (32 kilometers) thick under the continents (continental crust).
The problem behind your itchy skin might be insufficient vitamin intake. There are a number of vitamins that promote the hydration and healthiness of your skin. A shortage in these could trigger itchiness, dry skin and other skin conditions. Alternatively, an overdose of such vitamins might also lead to itchy skin.
Not eating enough fresh fruits and vegetables can cause the deficiency. People feel tired, weak, and irritable. Severe deficiency, called scurvy, causes bruising, gum and dental problems, dry hair and skin, and anemia. The diagnosis is based on symptoms and sometimes blood tests. Increasing consumption of fresh fruits and vegetables or taking vitamin C supplements by mouth usually corrects the deficiency.