To dream that your scab itches suggests that you are rushing the healing process or have become irritated by other offers of assistance. Try to relax and let the people who want to help you in your life do their work.... Dream Symbols and Analysis
To dream about a scab means you are thinking of something that has hurt you in the past.
If the scab was healing or dry, you are moving on from your past hurts. However, if the scab was sore or otherwise bothering you, this suggests that your past still has some influence on your life.... My Dream Interpretation