If the itchiness is causing your scalp to flake then check out the type of flakes you have as this can help identify what is causing them.
If the flakes are small and white it could be that the dryness is a skin reaction to a chemical in your shampoo in which case try our Hydrosil Scalp Shield Shampoo and Scalp Tonic.
If the patches of dryness are red or grey and raised and itchy and the flakes are grey or silver it may be that you have scalp psoriasis in which case our Oregon Shampoo would be better as it is designed for scalps prone to psoriasis.
This blog link may help you to determine what is causing your itchy scalp.
We would also recommend asking a doctor to look at your scalp and check the cause of the dryness.