What are the common locations on the body where cutaneous vasculitis can occur?

Common Locations of Cutaneous Vasculitis

Cutaneous vasculitis most commonly affects the lower extremities, particularly the shins and anterior tibial areas, with the legs being the predominant site in 60-85% of cases. 1, 2

Primary Distribution Patterns

Lower Extremities (Most Common)

• The shins and anterior tibial areas are the classic locations, presenting as palpable purpura or infiltrated erythema 1, 2
• The lower legs are affected in the majority of patients, with older UK-based studies reporting 60-85% of cases occurring at this site 1
• The dorsum of the feet can be involved, particularly in severe cases with ulceration 3
• Distribution on lower extremities is related to increased hydrostatic pressure and venous stasis, making these areas more vulnerable to vascular inflammation 2

Trunk and Upper Extremities

• The trunk can be involved, though less commonly than lower extremities 1
• Upper extremities may show lesions, particularly the extensor surfaces 1
• Head and neck involvement occurs in 29-54% of cases in some series, though this varies by underlying etiology 1

Special Anatomical Sites

• Adjacent to stomas in patients with inflammatory bowel disease, where pyoderma gangrenosum (a related vasculitic condition) commonly develops 1
• Genitalia can be affected, though this is less common 1
• Palms and soles may show petechiae in severe systemic vasculitis, particularly in meningococcemia 4

Distribution by Vasculitis Type

Superficial Small Vessel Vasculitis

• Presents as palpable purpura predominantly on dependent areas (lower legs, ankles) 2
• Lesions typically measure 2-20 cm in diameter 1
• Individual lesions persist >24 hours, distinguishing them from simple urticaria 5

Deep Dermal or Subcutaneous Vasculitis

• Manifests as nodular erythema, livedo racemosa, or deep ulcers 2
• Can present with digital gangrene when muscular vessels are involved 2
• Between the umbilicus and knees is the preferential location for ecthyma gangrenosum in neutropenic patients 1

Erythema Nodosum (Septal Panniculitis)

• Extensor surfaces of extremities, particularly anterior tibial areas are characteristic locations 1, 6
• Presents as raised, tender, red or violet subcutaneous nodules of 1-5 cm diameter 1
• Can involve trunk or upper extremities in addition to legs 1

Clinical Pitfalls

• Never dismiss non-blanching lesions on any body location without thorough evaluation, as distribution alone cannot exclude serious systemic vasculitis 4
• Lesions in atypical locations (face, trunk, upper extremities) may indicate systemic disease rather than isolated cutaneous vasculitis 2
• Biopsy should extend to the subcutis from the most tender, reddish, or purpuric lesion regardless of location to capture the full depth of vascular involvement 2
• Coexistence of pan-dermal and subcutaneous vessel involvement usually indicates connective tissue disease, ANCA-associated vasculitis, or malignancy-associated vasculitis 2