There is a section on my arms that have gotten lighter than the rest of me it was itchy at first and then, it stopped, now i notice it is really light?

There are many: causes of change in the amount of pigment, the substance that determines how dark our skin is .These include sun damage, skin injury, skin fungal infections, and a condition known as vitiligo. Since it was itchy in the beginning, you might have had a skin fungus called tinea versicolor. You would need to be seen by a doctor to find out for sure. Best wishes. Dr. Anne.