Navigating the Complexities of Granulomatosis with Polyangiitis Diagnosis

Show Notes

Background

• A vasculitis affecting small blood vessels causing inflammation and necrosis
• Affects upper respiratory tract (sinusitis, otitis media, saddle nose deformity), lungs (nodules, alveolar hemorrhage), and kidneys (rapidly progressive glomerulonephritis)
• Can lead to multi-organ failure, pulmonary hemorrhage, renal failure

Red Flag Symptoms:

• Chronic sinus symptoms
• Hemoptysis (especially bright red blood)
• New pulmonary complaints
• Renal dysfunction
• Constitutional symptoms (fatigue, weight loss, fever)

Workup in the ED:

• CBC, CMP for anemia and AKI
• Urinalysis with microscopy (hematuria, RBC casts)
• Chest imaging (CXR or CT for nodules, cavitary lesions)
• ANCA testing (not immediately available but important diagnostically)

Management:

• Stable patients: Outpatient workup, urgent rheumatology consult, prednisone 1 mg/kg/day
• Unstable patients: High-dose IV steroids (methylprednisolone 1 g daily x3 days), consider plasma exchange, cyclophosphamide or rituximab initiation, ICU admission

Conditions that Mimic GPA:

• Goodpasture syndrome (anti-GBM antibodies)
• TB, fungal infections
• Lung malignancy
• Other vasculitides (EGPA, MPA, lupus)

ANCA Testing Utility:

• C-ANCA/PR3-ANCA positive in 80-90% of GPA cases
• P-ANCA/MPO-ANCA more common in MPA
• Don’t delay treatment while awaiting results if suspicion is high

Outcomes:

• Without treatment: Fatal within a year (renal failure, respiratory complications)
• With treatment: 5-year survival ~75-90%, but ~50% relapse rate
• Long-term rheumatology follow-up is essential

Take-Home Points:

• Always include vasculitis in the differential for unexplained respiratory, renal, or systemic symptoms.
• Recognize pulmonary-renal syndromes early.
• Initiate high-dose steroids immediately for unstable patients without waiting for ANCA results.
• GPA is rare but life-threatening – early recognition saves lives.