Can urticarial vasculitis cause hypertension?

Can Urticarial Vasculitis Cause Hypertension?

Yes, urticarial vasculitis can cause hypertension, particularly in the hypocomplementemic form which carries a worse prognosis and is associated with systemic manifestations including renal involvement.

Understanding the Association

Hypertension in urticarial vasculitis occurs through two primary mechanisms:

• Renal involvement: When urticarial vasculitis affects the kidneys (as part of systemic small-vessel vasculitis), it can lead to glomerulonephritis, which frequently presents with hypertension 1

• Systemic vasculitic disease: The hypocomplementemic variant of urticarial vasculitis represents a more severe systemic disease that can affect multiple organs, including the kidneys, leading to secondary hypertension 2

Clinical Distinction: Hypocomplementemic vs Normocomplementemic Disease

Patients with urticarial vasculitis require serum complement assays for C3 and C4 to distinguish normocomplementaemic from hypocomplementaemic disease, which carries a worse prognosis 1.

The hypocomplementemic form is more likely to present with:

• Systemic manifestations including renal disease
• Hypertension as a complication
• Association with systemic lupus erythematosus
• More severe overall disease course

Diagnostic Approach When Hypertension is Present

When evaluating a patient with urticarial vasculitis and hypertension, you must:

1. Confirm vasculitis histologically: Lesional skin biopsy showing leucocytoclasia, endothelial cell damage, perivascular fibrin deposition, and red cell extravasation 1

2. Perform full vasculitis screen including:

   • Serum complement C3 and C4 levels
   • Urinalysis for hematuria, proteinuria, and red cell casts
   • Quantification of proteinuria (>3g/day indicates glomerular damage) 2
   • Renal function tests (creatinine, urea)
   • Anti-C1q antibodies if hypocomplementemic 3

3. Screen for underlying systemic disease: Look for systemic lupus erythematosus, infections, or malignancy 2

Important Clinical Caveat

Hypertension can occur even in the absence of urinary abnormalities, though this is unusual. A case report documented severe hypertension in a child with HSP (IgA vasculitis, a related condition) without glomerulonephritis features 4. However, this is rare, and you should always thoroughly investigate for renal involvement when hypertension is present 2.

Treatment Implications

When hypertension complicates urticarial vasculitis:

• ACE inhibitors should be used with caution in urticaria if angioedema is present 1
• Cyclosporine carries risk of hypertension as a side effect and requires blood pressure monitoring every 6 weeks 5
• The underlying vasculitis requires immunosuppressive therapy, not just antihypertensive management
• Systemic corticosteroids are often necessary for disease control 6, 7

Prognosis

The presence of hypertension in urticarial vasculitis signals more severe systemic disease. In hypocomplementemic urticarial vasculitis, 5-year and 10-year survival rates are 92% and 83% respectively, with end-stage renal disease identified as one of the causes of mortality 8.