The next step in managing this patient's pruritus is to obtain a chest radiograph for possible Hodgkin lymphoma, which is the malignant disease most strongly associated with pruritus. When primary skin lesions are absent, especially when pruritus is generalized, systemic causes of pruritus are suspected. A systemic disease or medication reaction is found in 14% to 24% of patients with generalized pruritus without a primary skin rash. The investigation begins with the history, including a medication history, since medications can cause pruritus. A review of systems should be performed to investigate for thyroid disorders, lymphoma, kidney and liver diseases, and diabetes mellitus. Initial laboratory evaluation for occult systemic disease includes a complete blood count with differential, thyroid function studies, and measurement of serum alkaline phosphatase, bilirubin, creatinine, and blood urea nitrogen levels. A CT scan of the chest, abdomen, and pelvis is not recommended without earlier studies that indicate the need for widespread imaging.

A skin biopsy of normal appearing skin is unlikely to contribute useful information; however, a biopsy would be indicated if the patient had pruritus and primary skin changes.

No further testing is not an appropriate choice since the patient has an impaired quality of life from the pruritus, and up to a 25% of patients with diffuse pruritus without a rash can have an indolent metabolic or malignant process.