Your skin is either itchy because it is dry or the body wash caused contact dermatitis. Either way you should use a moisturizing lotion. Try one with out dyes or fragrance in case your skin is sensitive. A brand like Eucerin or Jergens with aloe. When you shower use a moisturizing soap.
The first thing you should do is to find the cause of the itching. Is it dry skin, contact dermatitis, eczema, a seasonal allergy, a reaction to a medication or something else? You might use Caladryl lotion which is a topical analgesic skin protectant that reduces inflammation as well as itching. It can be purchased over the counter without a prescription and it does not contain any steroids and can be used as often as needed.