The crown of my hair gets really itchy. once i shampoo the itching goes away but comes back the next day. there is no burning, just itching.

Dry skin?: Unless your shampoo contains an active medication, I suspect that it is the water and not the shampoo which relieved the itch. Have you tried a moisturizing conditioner or shampoo? Another possibility is that you may have a contact allergy to one of the ingredients in your shampoo which does not start to cause problem until 24-72 hours later. See dermatologist if problem persists.