What is the treatment for urticarial vasculitis?

Treatment for Urticarial Vasculitis

Oral corticosteroids are the most effective first-line treatment for urticarial vasculitis, with efficacy in over 80% of patients, though immunomodulatory agents should be added for corticosteroid-sparing effects in chronic cases. 1

Diagnosis and Initial Assessment

Before initiating treatment, proper diagnosis is essential:

• Lesional skin biopsy is mandatory to confirm small-vessel vasculitis histologically (leucocytoclasia, endothelial cell damage, perivascular fibrin deposition, red cell extravasation) 2
• Perform a full vasculitis screen, including serum complement assays (C3 and C4) to distinguish normocomplementemic from hypocomplementemic disease 2
• Clinical features that suggest urticarial vasculitis rather than chronic urticaria:
  • Wheals lasting longer than 24 hours (vs. 2-24 hours in ordinary urticaria) 2
  • Burning sensation of the skin rather than itching 3
  • Residual hyperpigmentation after lesions resolve 3

Treatment Algorithm

First-Line Therapy:

1. Systemic Corticosteroids (prednisone/prednisolone)
   • Most effective for both cutaneous and systemic manifestations 1
   • Indicated especially for moderate to severe disease (UVAS7 >7) 4
   • Caution: Long-term administration can lead to serious adverse effects 1

Second-Line/Steroid-Sparing Agents:

For patients requiring prolonged treatment or with inadequate response to corticosteroids:

• Immunomodulatory/Immunosuppressive Agents:
  • Dapsone: Effective for both skin and systemic symptoms 1, 5
  • Hydroxychloroquine: Particularly useful in UV associated with autoimmune conditions 1, 5
  • Colchicine: Effective for skin manifestations 1
  • Mycophenolate mofetil: Associated with long-lasting treatment-free responses 5
  • Cyclosporine: Effective for both skin and systemic symptoms 1

For Severe or Refractory Cases:

• Cyclophosphamide: For severe systemic involvement, especially hypocomplementemic UV 1, 5
• Biologics:
  • Omalizumab: Emerging evidence of efficacy 1, 4, 5
  • Anti-IL-1 agents: Effective in selected cases 4, 5
  • Rituximab: Associated with long-lasting treatment-free responses 5

For Mild Cases (Skin-Limited or UVAS7 ≤7):

• Consider step-wise approach similar to chronic urticaria 4:
  • Second-generation H1-antihistamines (though often less effective than in chronic urticaria) 4
  • Omalizumab
  • Cyclosporine A

Special Considerations

• Hypocomplementemic UV requires more aggressive treatment due to worse prognosis and higher risk of systemic involvement 2, 6
• Associated conditions must be addressed:
  • Withdraw offending drugs if drug-induced
  • Treat underlying infections or malignancies if present 1
  • Manage associated autoimmune diseases (especially SLE) 6

Monitoring and Prognosis

• Monitor complement levels (C3, C4) to assess disease activity
• Hypocomplementemic UV has 5-year and 10-year survival rates of 92% and 83%, respectively 5
• Main causes of mortality include chronic obstructive pulmonary disease, septicemia, and end-stage renal disease 5

Common Pitfalls to Avoid

1. Misdiagnosis: Failing to perform skin biopsy may lead to misdiagnosis as chronic spontaneous urticaria and inadequate treatment 3
2. Overreliance on antihistamines: H1-antihistamines, montelukast, H2-antihistamines are generally not effective for most UV patients 1
3. Inadequate systemic evaluation: Failing to screen for complement levels and systemic involvement can miss associated conditions and lead to undertreating more severe disease 2
4. Prolonged corticosteroid use: Long-term corticosteroid monotherapy without steroid-sparing agents can lead to significant adverse effects 1

The treatment of urticarial vasculitis remains challenging due to limited high-quality evidence, with most recommendations based on case reports and retrospective studies rather than randomized controlled trials 1, 3.