How should I evaluate and initially manage an 86-year-old woman presenting with generalized pruritus?

Evaluation and Management of Generalized Pruritus in an 86-Year-Old Woman

Start immediately with emollients containing high lipid content applied at least twice daily to all pruritic areas, combined with 1% hydrocortisone cream applied 3-4 times daily for 2 weeks to treat the most common cause in elderly patients—asteatotic eczema from xerotic skin. 1, 2

Initial Topical Management

• Apply emollients with high lipid content at least twice daily as the cornerstone of therapy, since elderly skin has severely impaired barrier function and increased transepidermal water loss 1
• Use 1% hydrocortisone cream 3-4 times daily for 2 weeks to exclude asteatotic eczema, which is the most common cause of generalized pruritus in the elderly 1, 2
• Advise the patient to avoid frequent hot water bathing and harsh soaps, as these worsen xerosis 1
• Keep nails short to minimize excoriation 3

Medication Review

• Review all current medications immediately, as calcium channel blockers and hydrochlorothiazide are important causes of pruritic skin eruptions in older patients 4
• Never prescribe sedating antihistamines due to increased risk of falls, confusion, and potential contribution to dementia 1

Diagnostic Workup to Identify Underlying Systemic Causes

Generalized pruritus has a significant underlying systemic cause in 20-30% of elderly patients 3. The following investigations should be performed:

Essential Laboratory Tests

• Complete blood count with differential to exclude hematologic malignancies (chronic lymphocytic leukemia, polycythemia vera) and iron deficiency anemia—the most common systemic cause 1, 5
• Iron studies and ferritin, as iron deficiency anemia is the most frequent systemic cause of generalized pruritus 5
• Comprehensive metabolic panel including liver function tests (ALT, AST, alkaline phosphatase, bilirubin, GGT) to evaluate for hepatobiliary disease 1
• Renal function tests (creatinine, BUN) to exclude chronic kidney disease 1
• Thyroid function tests (TSH, free T4) to exclude hypothyroidism 1, 5
• Fasting glucose or hemoglobin A1c to screen for diabetes mellitus 5

Additional Tests if Initial Workup is Negative

• ESR or CRP if inflammatory conditions are suspected 1
• Vitamin B12 level, as deficiency is associated with generalized pruritus 5

Critical Diagnostic Consideration: Bullous Pemphigoid

Maintain high suspicion for bullous pemphigoid, which can present with pruritus alone in elderly patients before any blisters appear. 3, 6

• If pruritus persists despite adequate topical therapy for 2-4 weeks, consider skin biopsy with direct immunofluorescence to exclude bullous pemphigoid 1, 6
• This diagnosis is particularly important because it responds well to specific treatment with dapsone or systemic corticosteroids 6

Second-Line Systemic Therapy (If No Improvement After 2 Weeks)

If pruritus persists after 2 weeks of adequate topical therapy:

• Add a non-sedating antihistamine: fexofenadine 180 mg daily or loratadine 10 mg daily for symptomatic relief 1
• Consider gabapentin 100-300 mg at bedtime if pruritus persists, as it has specific efficacy for elderly skin pruritus 1
• Topical clobetasone butyrate or menthol preparations may provide additional relief 1

Treatments to Avoid

• Never use sedating antihistamines (increased fall risk, confusion, anticholinergic effects) 1
• Do not use crotamiton cream (ineffective) 1
• Avoid calamine lotion for generalized pruritus of unknown origin 1

Follow-Up and Referral Criteria

• GPs should regularly follow up patients with generalized pruritus where the underlying cause is not immediately evident 3
• Refer to dermatology if:
  • No improvement after 2-4 weeks of first-line therapy 1
  • Diagnostic uncertainty exists 3, 1
  • Skin biopsy is needed to exclude bullous pemphigoid, cutaneous lymphoma, or other serious conditions 1
• Consider urgent referral if constitutional symptoms suggest underlying malignancy, as paraneoplastic pruritus can manifest as generalized itching 1

Rare but Important Differential Diagnoses

• Neuropathic pruritus may cause generalized truncal pruritus, especially in patients with diabetes 4
• Mycosis fungoides (cutaneous T-cell lymphoma) can rarely present with persistent generalized pruritus as the only manifestation 7
• Scabies and transient acantholytic dermatosis are more common in elderly patients and should be considered 4