Systemic Vasculitis

Question · easy

A 74-year-old woman presents with 3 weeks of new right temporal headache, scalp tenderness when brushing her hair, and aching of her jaw after chewing a few bites. ESR is 96 mm/h. She reports one brief episode of blurred vision yesterday. What is the most appropriate immediate step?

Reassure and repeat ESR in 4 weeks if symptoms persist Order MRI of the brain and lumbar puncture to exclude meningitis Schedule outpatient temporal artery biopsy and await histology before treating Start high-dose prednisone now and arrange temporal artery biopsy within 2 weeks

Question · medium

A 52-year-old man has fever, weight loss, livedo reticularis, painful deep calf ulcers, and an asymmetric right foot drop. Blood pressure is 168/98 mmHg. Urinalysis shows proteinuria and hematuria but NO red-cell casts; serum creatinine is normal. ANCA testing is negative. Mesenteric angiography reveals multiple saccular microaneurysms. Which feature of this case is most characteristic of polyarteritis nodosa rather than an ANCA-associated vasculitis?

The presence of constitutional symptoms such as fever and weight loss The presence of livedo reticularis and skin ulcers The elevated erythrocyte sedimentation rate Renovascular hypertension without glomerulonephritis, with negative ANCA

Question · medium

A 48-year-old woman with a 6-year history of difficult-to-control asthma and chronic sinusitis develops numbness and weakness of the left foot (mononeuritis multiplex) and palpable purpura on her legs. Labs show 22% peripheral eosinophils (absolute count 2600/µL). ANCA testing is negative. Which statement about her likely diagnosis is correct?

ANCA are positive in only about 40-60% of EGPA cases, so a negative result does not exclude it She should be diagnosed with granulomatosis with polyangiitis because of the sinusitis A negative ANCA excludes the diagnosis of eosinophilic granulomatosis with polyangiitis Echocardiography is unnecessary because cardiac involvement is rare in this condition

Question · medium

A 55-year-old man with fatigue, arthralgias, palpable purpura on his lower extremities, and peripheral neuropathy is found to have a membranoproliferative glomerulonephritis, a very low C4, and a positive rheumatoid factor. Which of the following is the most important initial step in management?

Start lifelong anticoagulation for presumed thrombotic vasculopathy Perform a temporal artery biopsy to exclude giant cell arteritis Begin high-dose cyclophosphamide and plasma exchange immediately Test for hepatitis C (antibody and RNA) and treat the infection as first-line therapy

Question · hard

A 60-year-old man with biopsy-proven PR3-ANCA-positive GPA achieved complete remission 18 months ago after rituximab induction and is on maintenance azathioprine. He feels well, has a normal exam, and his CRP is normal. Routine testing shows his PR3-ANCA has risen from negative to strongly positive. What is the most appropriate management?

Continue current management and monitor clinically, because an ANCA rise alone does not warrant escalation Immediately re-induce with rituximab and high-dose glucocorticoids to prevent relapse Stop azathioprine and observe without any follow-up Add cyclophosphamide to his regimen empirically