A 35-year-old Indian man presents with recurrent oral ulcers, genital ulcers, and ocular inflammation. Pathological examination shows necrotizing vasculitis affecting small and medium vessels. What is the most common cause of death in this vasculitis syndrome?

Explanation

## Behçet Disease: Cardiovascular Complications as Leading Cause of Death **Key Point:** Behçet disease (BD) is a chronic, relapsing vasculitis affecting small and medium vessels. Cardiovascular involvement is the most common cause of mortality, primarily through thrombosis and aneurysm formation. ### Behçet Disease Overview Behçet disease is a systemic vasculitis of unknown etiology with high prevalence in the Mediterranean, Middle East, and Asia (including India). The classic triad includes: 1. Recurrent oral ulcers (>95% of patients) 2. Genital ulcers (75%) 3. Ocular involvement (50–70%) ### Mortality and Morbidity Patterns in Behçet Disease | Complication | Frequency | Mortality Impact | Pathophysiology | |--------------|-----------|------------------|------------------| | **Cardiovascular** | 5–50% | **Highest** | Thrombosis, aneurysm, pericarditis | | **Pulmonary** | 5–10% | Moderate | Hemorrhage, infarction (rare) | | **Renal** | 1–5% | Low | Glomerulonephritis (uncommon) | | **Neurological** | 5–10% | Moderate | CNS vasculitis, stroke | | **GI** | 5–60% | Low–Moderate | Ulceration, perforation | **High-Yield:** **Cardiovascular involvement is the most common cause of death in Behçet disease.** The mechanisms include: - **Venous thrombosis** (deep vein thrombosis, superior vena cava syndrome) — most common vascular manifestation - **Arterial aneurysms** (pulmonary artery, aorta) — life-threatening rupture - **Myocarditis and pericarditis** — can lead to sudden cardiac death ### Clinical Pearl Male gender, young age at onset, and HLA-B51 positivity are associated with more severe disease and higher risk of vascular complications. Vascular involvement occurs in 5–50% of BD patients, but accounts for the majority of deaths. ### Why Other Options Are Less Common Causes of Death | Complication | Why Not Most Common | |--------------|---------------------| | **Pulmonary hemorrhage** | Occurs in <10% of cases; pulmonary artery aneurysm rupture is rare | | **Renal failure** | Renal involvement is uncommon (<5%); glomerulonephritis is not a major feature | | **Neurological** | CNS vasculitis occurs in 5–10%; rarely fatal compared to vascular complications | **Mnemonic:** **BEHÇET** — **B**lood vessel involvement (thrombosis, aneurysm), **E**yes (uveitis), **H**istory of recurrent ulcers, **Ç**ardiovascular (most lethal), **E**rythema nodosum, **T**hrombophilia.