What is the treatment for prurigo?

Treatment for Prurigo

For prurigo, the recommended first-line treatment is topical moderate to high-potency corticosteroids, such as mometasone furoate 0.1% or betamethasone valerate 0.1% ointment, applied once or twice daily, with oral antihistamines as adjunctive therapy. 1

First-Line Treatment Options

Topical Therapies:

• Topical corticosteroids:

  • Moderate to high-potency corticosteroids for body lesions 1
  • Low-potency hydrocortisone for facial areas to avoid skin atrophy 1
  • For scalp application, solutions or foams penetrate better than creams 1
  • Treatment should be limited to 2 consecutive weeks with clobetasol propionate to avoid HPA axis suppression 2

• Other topical options:

  • Topical doxepin (limit to 8 days, 10% of body surface area, maximum 12g daily) 3
  • Menthol (counter-irritant effect) 3
  • Avoid crotamiton cream, topical capsaicin, and calamine lotion as they lack efficacy 3

Oral Antihistamines:

• Non-sedating antihistamines for daytime use:
  • Fexofenadine 180mg
  • Loratadine 10mg 3, 1
• Mildly sedating antihistamines for nighttime pruritus:
  • Cetirizine 10mg 3, 1
• Consider H1 and H2 antagonists in combination (e.g., fexofenadine and cimetidine) 3

Second-Line Treatment Options

If symptoms persist after 2 weeks of initial therapy:

Systemic Medications:

• GABA agonists:

  • Pregabalin (25-150 mg daily)
  • Gabapentin (900-3600 mg daily) 1

• Antidepressants:

  • Mirtazapine (30 mg daily) - particularly effective for lymphoma-associated pruritus 1
  • Selective serotonin reuptake inhibitors (paroxetine, fluvoxamine, sertraline) 3, 1

• Other systemic options (limited evidence):

  • Naltrexone
  • Aprepitant 80 mg daily (antagonist of neurokinin receptor 1) 3
  • Azathioprine (25-175 mg daily) - note high proportion of side effects 3

Phototherapy:

• UVB phototherapy or PUVA for resistant cases 4, 5

Management of Severe or Refractory Prurigo

For severe (Grade 3) or intolerable pruritus:

• Interrupt treatment until symptoms improve to Grade 0-1
• Consider dermatology consultation for possible skin biopsy and further evaluation 1
• For chronic nodular prurigo (prurigo nodularis), newer targeted therapies such as nemolizumab are being investigated 5

Special Considerations

Underlying Conditions

• Always investigate for potential underlying causes:
  • Hematological disorders (complete blood count, blood smear, LDH, ESR)
  • Polycythemia vera (JAK2 V617F mutation)
  • Lymphoma (night sweats, weight loss, fever, lymph node enlargement)
  • Chronic kidney disease
  • Cholestatic liver disease 1

Patient Education

• Regular application of emollients to prevent skin dryness
• Avoidance of triggers that exacerbate symptoms
• Stress reduction techniques 1

Treatment Algorithm

1. Initial Assessment:

   • Evaluate for underlying conditions
   • Determine prurigo subtype (nodular, multiformis, etc.)

2. First-Line Treatment (2-week trial):

   • Topical corticosteroids appropriate for affected area
   • Oral non-sedating antihistamines for daytime, mildly sedating for nighttime

3. If Inadequate Response:

   • Add GABA agonists (pregabalin or gabapentin)
   • Consider antidepressants (mirtazapine or SSRIs)

4. For Refractory Cases:

   • Dermatology referral
   • Consider phototherapy
   • Evaluate for clinical trials of newer targeted therapies

5. Reassessment:

   • After 2 weeks of treatment
   • If improved, continue until resolution then taper
   • If worsening, escalate therapy or refer to dermatology 1

Pitfalls and Caveats

• Avoid prolonged use of high-potency topical corticosteroids (>2 weeks) due to risk of HPA axis suppression 2
• Sedative antihistamines should be avoided in elderly patients due to increased risk of adverse effects 1
• Azathioprine, while effective in some cases, carries significant side effect risks 3
• The chronic nature of prurigo often requires combination and sequential treatments tailored to disease exacerbations 4
• Prurigo can significantly compromise quality of life and may require systemic immunosuppressants, immunobiologicals, or JAK inhibitors despite their cost and potential adverse effects 6