Vasculitis Diagnosis Differential

When considering a diagnosis of vasculitis, it's crucial to approach the differential diagnosis systematically, taking into account the clinical presentation, laboratory findings, and imaging studies. The differential can be organized into the following categories:

• Single Most Likely Diagnosis
  • Giant Cell Arteritis (GCA): This is often considered in patients over 50 presenting with symptoms such as headache, scalp tenderness, jaw claudication, and visual disturbances. GCA is a large vessel vasculitis that can lead to significant morbidity if not promptly treated.
• Other Likely Diagnoses
  • Polyarteritis Nodosa (PAN): A medium vessel vasculitis that can present with systemic symptoms like fever, weight loss, and hypertension, along with specific organ involvement such as renal or gastrointestinal symptoms.
  • Wegener's Granulomatosis (Granulomatosis with Polyangiitis, GPA): Characterized by the triad of respiratory tract granulomas, vasculitis, and glomerulonephritis. It often presents with symptoms like sinusitis, cough, and hemoptysis, along with renal involvement.
  • Microscopic Polyangiitis (MPA): A small vessel vasculitis that commonly presents with renal and pulmonary involvement, often manifesting as rapidly progressive glomerulonephritis and pulmonary hemorrhage.
• Do Not Miss Diagnoses
  • Kawasaki Disease: Although more common in children, it can occasionally present in adults. It's critical to recognize due to the risk of coronary artery aneurysms if not treated promptly.
  • ANCA-Associated Vasculitis: This includes conditions like GPA, MPA, and Eosinophilic Granulomatosis with Polyangiitis (EGPA). Missing these diagnoses can lead to significant organ damage and mortality.
  • Vasculitis due to Infections or Medications: Certain infections (e.g., endocarditis) or medications can cause vasculitis. Identifying and treating the underlying cause is crucial for resolution.
• Rare Diagnoses
  • Eosinophilic Granulomatosis with Polyangiitis (EGPA): Formerly known as Churg-Strauss syndrome, it is characterized by asthma, eosinophilia, and vasculitis affecting multiple organ systems.
  • Takayasu Arteritis: A large vessel vasculitis that primarily affects the aorta and its major branches, often presenting with systemic symptoms, hypertension, and diminished pulses in the limbs.
  • Behçet's Disease: A form of vasculitis that can affect vessels of all sizes, characterized by recurrent oral ulcers, genital ulcers, and uveitis, along with potential involvement of the skin, joints, and gastrointestinal and central nervous systems.

Each of these diagnoses requires careful consideration of clinical presentation, laboratory findings (including ANCA testing and biopsy when appropriate), and imaging studies to confirm the diagnosis and guide treatment.