Soap makes our skin feel dry and itchy because it cleans the natural oils that are produced by our skin. How does soap clean the natural oils? Well, there are tiny pin-shaped molecules in soap. Those pin-shaped molecules have two parts to them: the hydrophilic head and the hydrophobic tail. Hydrophilic means that it bonds or mixes with water and hydrophobic means that it is repelled by water. The hydrophobic head is attracted to oils and fats on your skin and the hydrophilic tail is attracted to water. When you was your hands and scrub for 20 seconds, the molecules lift the dirt and germs away and carries it with the water, down the drain.
Your skin needs these oils to protect it. When the oils are gone, your hands feel itchy and dry. To avoid this, make sure to put on a type of moisturizer to keep your skin oily!