What are the treatment options for itching?

Treatment for Itching

Start with potent topical corticosteroids (clobetasol propionate 0.05%) as first-line treatment for most cases of pruritus, followed by non-sedating oral antihistamines if topical therapy fails. 1, 2

First-Line Topical Treatments

Topical Corticosteroids

• Apply potent topical corticosteroids such as clobetasol propionate 0.05% to affected areas as initial therapy, limiting duration and body surface area to avoid adverse effects 2
• Over-the-counter hydrocortisone (0.2%-2.5%) can be used for minor skin irritations, applied 3-4 times daily to affected areas 3
• Note that low-potency over-the-counter hydrocortisone preparations have NOT been shown to improve symptoms in controlled trials, so prescription-strength agents are preferred for significant pruritus 1

Alternative Topical Options

• Topical menthol preparations provide counter-irritant effects that may relieve itching, though this is not a true antipruritic effect 1, 2
• Topical doxepin can be considered but must be limited to 8 days maximum, covering no more than 10% body surface area (maximum 12g daily) due to risk of allergic contact dermatitis 1
• Topical clobetasone butyrate (moderate-potency steroid) may provide benefit 1

Topical Agents to AVOID

• Do NOT use crotamiton cream - it has no significant antipruritic effect compared to vehicle 1, 2
• Do NOT use calamine lotion - there is no literature supporting its use 1, 2
• Do NOT use topical capsaicin for generalized pruritus (exception: may help in uremic pruritus only) 1, 2
• Topical antihistamines have insufficient evidence and may increase contact dermatitis risk 1

Second-Line Systemic Treatments

Oral Antihistamines

• Begin with non-sedating antihistamines: fexofenadine 180mg, loratadine 10mg, or mildly sedative cetirizine 10mg before using sedating agents 1, 2
• Consider combining H1 and H2 antagonists (e.g., fexofenadine plus cimetidine) for enhanced effect 1, 2
• Sedating antihistamines (hydroxyzine) should be reserved for short-term use or palliative settings only, as long-term use may predispose to dementia 1
• Note: Antihistamines have limited efficacy for non-histamine-mediated itch (such as atopic dermatitis or contact dermatitis) but may improve sleep quality 1

Third-Line Systemic Treatments

Neuropathic Pruritus Agents

• Gabapentinoids are effective for neuropathic itch: pregabalin 25-150mg daily or gabapentin 900-3600mg daily 1, 2
• These are particularly useful when pruritus has a neuropathic component 2

Antidepressants

• Consider paroxetine, fluvoxamine, or mirtazapine for refractory pruritus 1, 2
• These agents modulate central itch perception pathways 4

Neurokinin-1 Receptor Antagonists

• Aprepitant 80mg daily orally has shown efficacy in reducing pruritus in generalized pruritus of unknown origin and paraneoplastic cases 1, 2

Other Systemic Options

• Naltrexone or butorphanol (opioid antagonists/agonists) may be considered 1
• Ondansetron (serotonin antagonist) is another option 1

Physical Therapies

Phototherapy

• Narrowband UVB (NB-UVB) or broadband UVB (BB-UVB) can provide symptomatic relief for generalized pruritus 1, 2
• Particularly effective for uremic pruritus (BB-UVB has Grade A evidence) 1
• Also beneficial for pruritus associated with lymphoma and polycythemia vera 1

Cause-Specific Treatments

Iron Deficiency

• Iron replacement therapy for pruritus associated with iron deficiency 1

Hepatic Pruritus

• Rifampicin is first-line treatment for cholestatic/hepatic pruritus 1

Uremic Pruritus

• Ensure adequate dialysis, normalize calcium-phosphate balance, control parathyroid hormone, and correct anemia with erythropoietin 1
• Consider topical capsaicin cream or oral gabapentin (this is the exception where capsaicin may help) 1
• Renal transplantation is the only definitive cure 1

Lymphoma-Associated Pruritus

• Consider cimetidine, carbamazepine, gabapentin, or mirtazapine 1
• Oral corticosteroids may help in incurable cases 1

Critical Pitfalls to Avoid

• Always investigate for underlying systemic disease (renal disease, liver disease, lymphoma, iron deficiency, polycythemia vera, solid tumors) before labeling pruritus as idiopathic 1, 2, 4
• Avoid long-term sedating antihistamines due to dementia risk 1
• Do not use low-potency over-the-counter topical steroids expecting significant benefit - they lack evidence 1
• Reassess treatment efficacy after 2 weeks; if no improvement, escalate to next treatment option 2