What initial labs and symptomatic treatment should I order for an 84‑year‑old patient with generalized pruritus?

Initial Management of Generalized Pruritus in an 84-Year-Old Patient

Start immediately with high-lipid emollients applied at least twice daily to all pruritic areas plus 1% hydrocortisone cream applied 3-4 times daily for 2 weeks, while simultaneously ordering initial laboratory investigations to identify underlying systemic causes. 1, 2, 3

Immediate Symptomatic Treatment Orders

Topical Therapy (First-Line)

• Prescribe high-lipid content emollients to be applied at least twice daily to all affected areas, as elderly skin has severely impaired barrier function and increased transepidermal water loss 2, 4
• Prescribe 1% hydrocortisone cream to be applied 3-4 times daily for 2 weeks to exclude asteatotic eczema (xerosis-related eczema), which is the most common cause of generalized pruritus in elderly patients 2, 4, 3
• Instruct the patient to avoid hot water bathing and harsh soaps, as these worsen xerosis in elderly skin 2

Oral Therapy for Symptom Relief

• Add a non-sedating antihistamine: either fexofenadine 180 mg once daily OR loratadine 10 mg once daily for symptomatic relief of itching 2, 4
• Never prescribe sedating antihistamines (diphenhydramine, hydroxyzine, chlorpheniramine) in this 84-year-old patient due to increased risk of falls, confusion, and potential contribution to dementia 1, 2, 4

Essential Laboratory Investigations to Order Now

Hematological Workup

• Complete blood count with differential and blood film to evaluate for polycythemia vera, lymphoma, or other hematological malignancies 1
• Lactate dehydrogenase (LDH) as elevated levels suggest lymphoma 1
• Erythrocyte sedimentation rate (ESR) if available 1
• Ferritin and iron studies to exclude iron deficiency, which can cause generalized pruritus 1

Hepatic and Renal Function

• Comprehensive metabolic panel including liver function tests (ALT, AST, alkaline phosphatase, bilirubin, GGT) to evaluate for cholestatic liver disease, which commonly presents with pruritus 1, 2
• Renal function tests (creatinine, BUN, eGFR) to exclude uremic pruritus 1

Additional Screening

• Thyroid function tests (TSH, free T4) to exclude thyroid disease as a cause 2, 5
• Fasting glucose or HbA1c to screen for diabetes mellitus, which can cause neuropathic pruritus 6

Consider Based on History

• HIV and hepatitis B and C serology if risk factors are present 1
• Chest X-ray if constitutional symptoms (weight loss, night sweats, fevers) suggest lymphoma 1

Reassessment Timeline and Next Steps

At 2 Weeks

• If no improvement after 2 weeks of emollients and 1% hydrocortisone, escalate to clobetasone butyrate (a more potent topical steroid) for persistent areas 2, 4
• Review all laboratory results and address any abnormalities found 2

Second-Line Systemic Therapy

• If pruritus persists after adequate topical therapy, add gabapentin starting at 100-300 mg at bedtime, as it has specific efficacy for elderly skin pruritus and neuropathic itch 2, 4, 7

At 2-4 Weeks

• Refer to dermatology if no improvement after 2-4 weeks of first-line therapy, if diagnostic uncertainty exists, or if skin biopsy is needed to exclude bullous pemphigoid (which can present with pruritus alone before skin lesions appear in elderly patients), cutaneous lymphoma, or other serious conditions 2, 4

Critical Pitfalls to Avoid in This 84-Year-Old Patient

• Do NOT use sedating antihistamines (increased fall risk, confusion, dementia risk) 1, 2
• Do NOT use crotamiton cream (ineffective, Strength of recommendation B) 2, 8
• Do NOT use calamine lotion for generalized pruritus 2, 8
• Do NOT dismiss this as simple "senile pruritus" without completing the systemic workup, as over 50% of elderly patients with generalized pruritus have an identifiable underlying cause 5, 9
• Do NOT use cetirizine as first-line, as it causes mild sedation (13.7% vs 6.3% placebo) and is not recommended in elderly patients 2

Special Considerations for This Age Group

Polycythemia vera should be specifically considered if blood work shows elevated hemoglobin/hematocrit with microcytosis, raised white cell or platelet count, and low ESR; if suspected, order JAK2 V617F mutation testing (present in up to 97% of cases) 1

Aquagenic pruritus (intense itching after water contact without skin lesions) is characteristic of polycythemia vera and should be specifically asked about in the history 1

Neuropathic pruritus is frequently overlooked but may cause localized or generalized truncal pruritus, especially in patients with diabetes 6