My wife recently started having constant itching all over her body. she does not have any rashes on her. she has not changed any medications, soaps,?

Variety of reasons: There can be a variety of reasons for this type of itching. He will need a medical evaluation to clarify what your diagnosis is.

See a Doctor: There are many conditions that cause diffuse itching without rash. Most of these situations probably represent early stages of what will eventually cause a noticeable rash. These conditions include allergies, dry skin, liver and kidney disease, and certain B cell malignancies such as lymphoma. Keep her skin moist, use cool compresses and try an anti-histamine (which will also help her to rest).