Workup for Generalized Pruritus Without Rash in an 89-Year-Old Male
The workup for an 89-year-old male with generalized pruritus without rash should include full blood count, ferritin levels, liver function tests, and renal function tests as first-line investigations to identify common underlying systemic causes. 1, 2
Initial Laboratory Investigations
- Complete blood count and ferritin levels should be checked in all patients with chronic generalized pruritus without rash (GPWOR) to evaluate for iron deficiency, which is a common cause 1, 3
- Liver function tests (LFTs) should be performed to assess for hepatic causes of pruritus 1, 2
- Urea and electrolytes should be checked to evaluate renal function as uremic pruritus is common in elderly patients 1
- If iron deficiency is suspected but ferritin appears "normal," check serum iron and total iron binding capacity 1
- Consider checking thyroid function tests if clinical features suggest thyroid disease, though routine testing is not recommended without supporting symptoms 1, 2
Additional Targeted Investigations
- Hematological evaluation: If blood count abnormalities are present, consider blood film, lactate dehydrogenase, and erythrocyte sedimentation rate 1
- For suspected polycythemia vera: If raised hemoglobin/hematocrit is present, check for JAK2 V617F mutation 1
- For suspected liver disease: Consider bile acids and antimitochondrial antibodies if LFTs are abnormal 1, 2
- For suspected infection: Consider HIV and hepatitis A, B, and C serology if risk factors are present 1, 2
- Medication review: Perform thorough review of all medications as drug-induced pruritus is common in elderly patients 2, 4
Special Considerations for Elderly Patients
- Skin biopsy may be necessary in persistent, unexplained pruritus to rule out cutaneous lymphoma, which can present with normal-appearing skin 1, 2
- Iron studies are particularly important as iron deficiency anemia has been identified as the most common systemic cause of generalized pruritus in some studies 5, 3
- Exclude asteatotic eczema with careful skin examination, as this common condition in the elderly can cause generalized pruritus 2, 4
- Consider malignancy screening in elderly patients with chronic generalized pruritus without obvious cause 4, 6
When to Consider Referral
- Dermatology referral if pruritus persists despite initial workup and treatment 1, 4
- Hematology referral if blood abnormalities suggest polycythemia vera or lymphoma 1
- Hepatology referral for any significant hepatic impairment 1
- Neurology referral if neuropathic pruritus is suspected after initial evaluation 1
Common Pitfalls to Avoid
- Don't assume age-related dry skin is the only cause without proper investigation in elderly patients 2, 4
- Don't overlook iron deficiency even with "normal" hemoglobin, as it's a common reversible cause 1, 5
- Don't rely solely on ferritin as an indicator of iron status, as it's an acute phase protein and may be elevated despite iron deficiency 1, 3
- Don't miss drug-induced causes by failing to review all medications, including over-the-counter drugs 2, 4
- Don't delay workup as generalized pruritus can be the initial presenting symptom of serious systemic disease 6, 5