Management of Chronic Pruritus

Initial Assessment and Diagnostic Workup

• The British Journal of Dermatology recommends a thorough skin examination to identify primary lesions and secondary changes from scratching, with a focus on examining finger webs, anogenital region, nails, and scalp to identify subtle dermatoses 1, 2
• Reviewing all current medications is crucial to rule out drug-induced pruritus, as 20-30% of generalized pruritus cases have a significant underlying systemic cause 2
• For patients with chronic generalized pruritus without obvious dermatosis, the British Journal of Dermatology suggests obtaining a complete blood count with differential, comprehensive metabolic panel, ferritin levels, and thyroid-stimulating hormone, with a strength of evidence not specified 1, 2, 3

Treatment Algorithm by Etiology

Generalized Pruritus of Unknown Origin (GPUO)

• The British Journal of Dermatology recommends liberal and frequent application of emollients, topical menthol or clobetasone butyrate, and topical doxepin as first-line therapies for GPUO, with a strength of evidence not specified 1, 4, 5
• Non-sedative antihistamines, such as fexofenadine or loratadine, are recommended as second-line systemic therapies for GPUO, with a strength of evidence not specified 5
• Gabapentin or pregabalin are recommended as third-line options for GPUO, with a strength of evidence not specified 1, 4

Inflammatory Pruritus (Eczema, Psoriasis, Dermatitis)

• The British Journal of Dermatology recommends topical emollients and mild-to-moderate potency topical corticosteroids as first-line therapies for mild inflammatory pruritus, with a strength of evidence not specified 2, 6
• For moderate inflammatory pruritus, the British Journal of Dermatology suggests continuing emollients, using medium-to-high potency topical corticosteroids, and adding oral antihistamines, with a strength of evidence not specified 2

Systemic Disease-Associated Pruritus

Uraemic Pruritus

• The British Journal of Dermatology recommends optimizing underlying conditions, such as ensuring adequate dialysis and normalizing calcium-phosphate balance, as first-line treatments for uraemic pruritus, with a strength of evidence not specified 1, 3
• BB-UVB phototherapy is recommended as the most effective treatment for uraemic pruritus, with a strength of evidence rated as A 1

Hepatic/Cholestatic Pruritus

• The British Journal of Dermatology recommends a treatment hierarchy for hepatic/cholestatic pruritus, starting with rifampicin as first-line, followed by cholestyramine, sertraline, and naltrexone, with a strength of evidence not specified 1, 3

Drug-Induced Pruritus

Opioid-Induced Pruritus

• The British Journal of Dermatology recommends naltrexone as first-choice treatment for opioid-induced pruritus, with a strength of evidence rated as B 4

Psychogenic/Functional Pruritus

• The British Journal of Dermatology suggests psychosocial interventions, such as education on trigger avoidance and treatment application, lifestyle interventions, and relaxation techniques, as first-line treatments for psychogenic/functional pruritus, with a strength of evidence not specified 1, 3, 4

Critical Pitfalls to Avoid

Antihistamine Use

• The British Journal of Dermatology recommends avoiding long-term sedative antihistamines due to increased dementia risk, particularly in elderly patients, with a strength of evidence not specified 1, 3, 5, 6

Topical Corticosteroid Use

• The British Journal of Dermatology suggests limiting topical steroid use to 2 weeks maximum to prevent skin atrophy and other adverse effects, with a strength of evidence not specified 5, 6

Special Populations

Elderly Patients

• The British Journal of Dermatology recommends considering a 2-week trial of emollients combined with topical steroids to exclude asteatotic eczema, and avoiding long-term sedative antihistamines due to dementia risk, with a strength of evidence not specified 1, 3, 5, 6

Pregabalin for Pruritus Treatment

Introduction to Pregabalin Use

• The British Journal of Dermatology recommends pregabalin as an effective treatment option for neuropathic pruritus and uremic pruritus, but not as first-line therapy for most types of pruritus 7, 8

Dosage and Administration

• The National Comprehensive Cancer Network recommends starting with 50 mg three times daily, increasing to 100 mg three times daily based on tolerability, with a maximum dose of 600 mg daily in divided doses for refractory cases 9
• Slower titration is required for elderly or medically frail patients, with dose adjustment mandatory for renal insufficiency 9

Contraindications and Cautions

• The British Journal of Dermatology advises that gabapentin and pregabalin should not be used for hepatic/cholestatic pruritus, with a strength of recommendation of D 7, 8, 10
• Mandatory dose adjustment is required for renal impairment, as pregabalin is eliminated primarily by renal excretion 9

Treatment Guidelines

• The Clinical Infectious Diseases journal suggests gabapentin as the preferred first anticonvulsant trial for most pruritic conditions, with pregabalin considered after inadequate response to gabapentin 11