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.
Vitamin B2 plays a vital role in metabolism of fats and carbohydrates. A deficiency of this vitamin can cause skin lesions and light sensitivity. The vitamin is very good for eyes, mouth, skin and nails, so incorporate food stuff such as milk, mushrooms, meat, liver and dark green vegetables in your diet. Deficiency of Vitamin B3 results in pellagra associated with symptoms of sunburn, diarrhea, irritability, swollen tongue and mental instability.