Vasculitis: Diagnosis and Management

• The size of the involved vessels helps classify the vasculitis: small vessel involvement: palpable purpura, urticarial papules, vesicles, petechiae vs. medium vessel involvement=livedo reticularis, retiform purpura, ulcers, subcutaneous nodules, digital necrosis.

• To diagnose skin-limited vasculitis, you must first rule out systemic manifestations (renal, joint, GI) and underlying conditions.

• In small vessel vasculitis with a negative review of systems, the most important lab order is a UA with micro because the patient may not have symptoms but could have glomerulonephritis.