From your symptoms, atopic dermatitis
and seborrheic dermatitis
are two possibilities which need to be ruled out.
In atopic dermatitis
the skin reacts easily to irritants, food, and environmental allergens and becomes very itchy, which leads to scratching, redness, and flaky skin. Seborrheic dermatitis also presents with scaly, flaky, itchy, and red skin.
To differentiate both, you can get a biopsy skin done to confirm the diagnosis. Treatment is dependent on diagnosis.