Dermatology MCQ - Inflammatory Dermatoses - Management of urticarial vasculitis

A 45-year-old woman is diagnosed with normocomplementemic urticarial vasculitis after a biopsy confirmed leukocytoclastic vasculitis. Her lesions are confined to the skin and are moderately symptomatic. She has failed a trial of high-dose second-generation H1-antihistamines. According to standard treatment algorithms, which of the following is the most appropriate next-line agent for this patient?

A. Intravenous omalizumab
B. Oral colchicine
C. A short, tapering course of oral prednisone
D. Oral dapsone
E. Narrowband UVB phototherapy

Correct Answer: D. Oral dapsone

Answer & Explanation

Explanation:

The management of urticarial vasculitis (UV) is stepwise and depends on disease severity and systemic involvement. For skin-limited, normocomplementemic UV that has failed antihistamines, the next step is typically a trial of a non-immunosuppressive, anti-inflammatory agent.

• Dapsone is highly effective in this context due to its inhibitory effect on neutrophil chemotaxis and function, which directly targets the primary pathogenic cell in leukocytoclastic vasculitis. It is often considered a first-line systemic agent for cutaneous vasculitis without major systemic involvement.

The other options are less appropriate as the next step for this specific scenario:

• A. Intravenous omalizumab: Omalizumab (anti-IgE) is highly effective for chronic spontaneous urticaria, but it is generally not effective for urticarial vasculitis, as the pathophysiology is immune-complex and neutrophil-driven, not IgE and mast-cell driven.

• B. Oral colchicine: Colchicine is a reasonable option for cutaneous vasculitis and can be used. However, dapsone often has a stronger evidence base and is more frequently cited as the preferred first-choice agent after antihistamines fail in skin-limited UV. Colchicine is an alternative if dapsone is not tolerated or is contraindicated (e.g., G6PD deficiency).

• C. A short, tapering course of oral prednisone: While systemic corticosteroids are highly effective for acute control, they are not ideal for long-term management due to their side-effect profile. They are typically reserved for: 1) severe, debilitating skin disease, or 2) UV with systemic involvement. Using a short course would likely lead to rebound flares upon tapering, and the goal is to find a sustainable, long-term agent.

• E. Narrowband UVB phototherapy: Phototherapy has a limited role in UV. It is more commonly used for conditions like atopic dermatitis or psoriasis. It is not a standard treatment for vasculitic conditions.

Key Associations for Management of Urticarial Vasculitis

• Initial Workup: It is critical to rule out systemic disease. This includes checking for hypocomplementemia (low C3, C4, C1q), which is a marker for more severe disease and association with SLE. A full workup for infection, autoimmune disease, and paraproteinemia is mandatory.

• Stepwise Management for Skin-Limited Disease:

  1. First-line: Symptomatic control with NSAIDs (if not contraindicated) and H1/H2-antihistamines.

  2. Second-line: Dapsone or Colchicine.

  3. Third-line: Hydroxychloroquine.

• Management for Refractory or Systemic Disease:

  • Systemic Corticosteroids: (e.g., prednisone 0.5-1 mg/kg/day) are the cornerstone for initial control of severe or systemic disease.

  • Steroid-Sparing Immunosuppressants: For long-term control, agents like azathioprine, mycophenolate mofetil, or methotrexate are used.

  • Biologics: For severe, refractory cases, rituximab (anti-CD20) can be highly effective, especially in hypocomplementemic UV or cases associated with autoimmune disease.

• Prognosis: Normocomplementemic UV is often chronic but tends to be limited to the skin and has a more benign prognosis. Hypocomplementemic UV is associated with a greater risk of systemic involvement (arthralgias, glomerulonephritis, obstructive lung disease) and requires more aggressive therapy and monitoring.