I have been suffering from sever itchiness all over my body but especially in my feet, knees and hands. it gets worse and berry red when i scratch.

Allergist: It sounds like an allergic reaction to something internal or external. Think about what could be causing it. In the meantime take an anti histamine like benadryl(can make you drowsy) or claritin(less effective but doesn't cause drowsiness). See an allergist if symptoms persist.

Itchy skin: To have severe itching of the extremities may be a sign of an allergy to a food or a product. Are you a diabetic? Do you have other symptoms? Are you taking any medications that you may be allergic to? Your history is vague and does not have enough information. Go see a specialist who can prescribed something oral and topical for this problem.