Hello,
Itchy skin without any rash can be due to dry skin, psoriasis, dermatitis, scabies and hives, internal diseases like liver and kidney disorders, diabetes, iron deficiency anemia, irritation and allergic reactions to chemicals, wool, soaps, cosmetics and certain foods.
For such itching oral antihistamine such as Benadryl or Claritin can be used. If the symptoms persist then get an evaluation done from a dermatologist as topical and oral steroids may be needed after confirming the diagnosis.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your dermatologist. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.