Physical Examination Findings of Leukocytoclastic Vasculitis
The predominant physical examination finding of leukocytoclastic vasculitis is palpable purpura, which appears as raised, violaceous, non-blanching lesions typically distributed on the lower extremities and dependent areas. 1, 2
Key Cutaneous Manifestations
- Palpable purpura: The hallmark finding, consisting of raised, violaceous, non-blanching lesions
- Distribution pattern: Predominantly affects the lower extremities and dependent areas
- Additional cutaneous presentations:
- Petechiae (pinpoint hemorrhages)
- Papules (small raised lesions)
- Vesicles or bullae (fluid-filled lesions)
- Pustules (pus-filled lesions)
- Urticarial lesions (hive-like wheals)
- Ulcerations (in severe cases)
- Rarely, annular (ring-shaped) plaques 3
Timing and Evolution of Lesions
- Lesions typically develop over 24-48 hours
- Early lesions appear bright red or violaceous
- Older lesions evolve to show brownish-red discoloration due to hemosiderin deposition
- Lesions may coalesce to form larger patches or plaques
- Biopsy yield is highest within the first 24-48 hours of lesion appearance 4
Associated Physical Findings
- Extremity edema: Particularly painful hand or foot swelling 4
- Joint involvement: Arthralgia or frank arthritis may be present
- Systemic manifestations (when part of systemic vasculitis):
- Fever
- Weight loss
- Lymphadenopathy
- Abdominal pain
- Hematuria or proteinuria (suggesting renal involvement)
- Neurological symptoms (in cases with nervous system involvement)
Distinguishing Features from Other Vasculitic Disorders
- Urticarial vasculitis: Presents with urticarial wheals that persist >24 hours and may leave residual hyperpigmentation
- IgA vasculitis (Henoch-Schönlein purpura): Similar palpable purpura but often accompanied by abdominal pain, arthralgia, and renal involvement
- ANCA-associated vasculitis: May present with similar skin findings but typically has more prominent systemic involvement
Diagnostic Pearls
- The presence of palpable purpura strongly suggests leukocytoclastic vasculitis but requires histopathologic confirmation
- Lesions are often symmetrically distributed
- Lesions may be pruritic, painful, or asymptomatic
- New crops of lesions may appear as older ones resolve
- The distribution pattern often follows gravity-dependent areas
Common Pitfalls in Examination
- Failing to distinguish between blanching and non-blanching lesions (use diascopy or glass slide pressure)
- Mistaking non-palpable purpura (thrombocytopenia, coagulopathy) for vasculitis
- Overlooking subtle systemic manifestations that might indicate a more serious underlying disorder
- Delaying biopsy beyond 48 hours, which significantly reduces diagnostic yield 4
Early recognition of these characteristic physical examination findings and prompt biopsy within 24-48 hours of lesion appearance are essential for accurate diagnosis and appropriate management of leukocytoclastic vasculitis.