MKSAP Quiz: itching lasting 5 months
A 53-year-old man is evaluated for whole-body itching lasting 5 months that is not improved by a short course of emollients and antihistamine medication. Review of systems is negative. He does not take any medications. On physical examination, excoriations are noted on his legs, shoulders, and back; the remainder of the examination is normal. After normal results on laboratory tests, what is the most appropriate next step in management?
A 53-year-old man is evaluated for itching lasting 5 months. He reports that his whole body is itchy and that a short course of emollients and antihistamine medication did not improve his symptoms. He feels well otherwise. Review of systems is negative including findings for fever, fatigue, and unintentional weight loss. He does not take any medications.
On physical examination, vital signs are normal. Examination of the skin reveals no signs of xerosis or inflammation. Excoriations are noted on his legs, shoulders, and back. The remainder of the physical examination, including thyroid and lymph node examinations, is normal.
A complete blood count, metabolic profile, serum thyroid-stimulating hormone level, liver chemistry tests, and HIV antibody assay are normal.
Which of the following is the most appropriate next step in management?
A. Chest radiograph
B. CT scan of the chest, abdomen, and pelvis
C. Skin biopsy
D. No further testing
MKSAP Answer and Critique
The correct answer is A. Chest radiograph. This item is available to MKSAP 17 subscribers as item 22 in the Dermatology section. More information is available online.
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.
Key Point
- When pruritus is generalized and primary skin lesions are absent, systemic causes of pruritus should be sought.