What is the best approach to manage pruritus in a patient?

Management of Pruritus

Begin with emollients and identify the underlying cause through systematic investigation, as 20-30% of generalized pruritus cases have a significant underlying systemic disease that requires specific treatment. 1

Initial Assessment and First-Line Management

Immediate Steps

• Apply emollients liberally as the foundation of all pruritus management, regardless of cause, to address xerosis which lowers the threshold for itch 1
• Provide self-care advice including keeping nails short to prevent scratch-induced complications 1
• Trial a non-sedating antihistamine for symptomatic relief, though evidence for efficacy in non-histamine-mediated pruritus is limited 1

Critical Diagnostic Workup

Always exclude physical causes before attributing pruritus to psychological factors 1, 2. The initial investigation should include:

• Full blood count with differential to screen for hematological malignancies (lymphoma, polycythemia vera) 1
• Renal function tests (urea, creatinine) as 42% of hemodialysis patients experience pruritus 1
• Liver function tests (bilirubin, alkaline phosphatase) for cholestatic causes 3
• Thyroid-stimulating hormone for endocrine disorders 3, 4
• Fasting glucose or A1C for diabetes-related neuropathy 1
• Lactate dehydrogenase and ESR if hematological malignancy suspected 1

Cause-Specific Treatment Algorithms

Hematological Causes

For Polycythemia Vera-Associated Pruritus:

• Aspirin 300 mg daily is effective even when blood counts are normalized 1
• Consider SSRIs, PUVA/UVB phototherapy, cimetidine, or atenolol as alternatives 1
• Ruxolitinib (JAK1/JAK2 inhibitor) produces rapid reductions in pruritus scores 1

For Lymphoma-Associated Pruritus:

• Treat with gabapentin, carbamazepine, mirtazapine, cimetidine, or phototherapy 1
• High-dose oral corticosteroids for palliative relief in incurable disease 1

Renal Causes (Uremic Pruritus)

Optimize dialysis adequacy first (target Kt/V around 1.6) and ensure high-flux hemodialysis over standard filtration 1

Pharmacological Management:

• Gabapentin 100-300 mg three times weekly after dialysis (note: lower doses than non-ESRD population) 1
• Avoid long-term sedating antihistamines due to dementia risk 1
• Topical capsaicin depletes substance P in peripheral sensory neurons 1

Stress-Related/Psychogenic Pruritus

Diagnostic criteria require:

• Chronic pruritus >6 weeks 1, 2
• No somatic cause identified 1, 2
• Variations in intensity with stress 1, 2

Treatment approach:

• Psychosocial and behavioral interventions including education on trigger avoidance, relaxation techniques, cognitive restructuring, and habit reversal training 1, 2
• Patient support groups reduce dermatologist visits by 27% 1, 2
• Consider referral to liaison psychiatry or psychology 1
• Moderate-to-high potency topical corticosteroids for symptomatic relief 2, 5

HIV-Associated Pruritus

• Indomethacin 25 mg three times daily is more effective than sedating antihistamines, though gastric intolerance may occur 1
• UVB phototherapy has demonstrated efficacy 1
• Always exclude scabies, which can present with severe pruritus and minimal skin signs in HIV patients 1

Common Pitfalls and Caveats

Critical Warnings

• Never diagnose psychogenic pruritus without comprehensive physical evaluation including iron studies, metabolic panel, thyroid function, and medication review 2
• Up to 33% of chronic pruritus patients develop anxiety and depressive disorders, significantly impairing quality of life comparable to chronic pain 1, 2
• Pruritus can be the sole presenting feature of bullous pemphigoid in elderly patients, requiring skin biopsy and immunofluorescence 1
• Skin lymphoma may present with pruritus and normal-appearing skin 1

Follow-Up Requirements

• Regular follow-up is essential as the underlying cause may not be evident initially 1
• Refer to secondary care if diagnostic doubt exists or symptoms persist despite primary management 1
• In elderly patients (>65 years), treat with emollients and topical steroids for at least 2 weeks before escalating therapy 1

Drug-Induced Considerations

• Obtain complete medication history including over-the-counter and herbal remedies 1
• Biological cancer therapies commonly cause pruritus as a side effect 1
• Opioid-induced pruritus may respond to acupuncture 1

When Conservative Management Fails

Consider phototherapy (BB-UVB or combined UVA/UVB) for cholestatic, HIV-associated, or refractory cases 1

Evaluate for malignancy in older patients with chronic generalized pruritus without primary skin lesions, as solid tumors are a rare but important cause 1, 4