Constitutional Symptoms in GPA vs EGPA
Constitutional symptoms (fever, weight loss, malaise, fatigue) are more common in Churg-Strauss syndrome/EGPA than in Wegener's granulomatosis/GPA, particularly during the vasculitic phase of EGPA.
Clinical Presentation Patterns
EGPA (Churg-Strauss) Constitutional Features
EGPA characteristically progresses through three phases, with constitutional symptoms most prominent during the vasculitic phase 11. The disease evolves from:
- Allergic phase: Asthma and chronic rhinosinusitis (can last years)
- Eosinophilic phase: Eosinophilia with end-organ involvement
- Vasculitic phase: Constitutional symptoms emerge alongside systemic vasculitis manifestations (mononeuritis multiplex, glomerulonephritis, purpura)
The vasculitic phase of EGPA is specifically characterized by constitutional symptoms as a defining feature 2. These systemic symptoms accompany the necrotizing vasculitis affecting small-to-medium vessels and occur in conjunction with peripheral neuropathy and purpura.
GPA (Wegener's) Constitutional Features
GPA typically presents with more localized symptoms initially 34:
- Destructive sinonasal lesions
- Pulmonary nodules
- Pauci-immune glomerulonephritis
- Necrotizing granulomatous inflammation
While GPA can progress from limited to generalized disease, the hallmark manifestations are organ-specific (upper respiratory tract destruction, lung nodules, renal disease) rather than prominent constitutional symptoms 5.
Key Distinguishing Features
The clinical features that separate these entities include:
- EGPA: Atopy, peripheral blood eosinophilia, tissue eosinophilia, asthma (>90% of patients), constitutional symptoms during vasculitic phase 62
- GPA: Necrotizing granulomatous respiratory tract lesions, c-ANCA/PR3 positivity (more common than in EGPA), destructive upper airway disease 45
ANCA Status and Symptom Patterns
ANCA positivity affects symptom distribution in EGPA 11:
- ANCA-positive EGPA (~40%): More vasculitic features (glomerulonephritis, peripheral neuropathy, purpura)
- ANCA-negative EGPA: More eosinophilic features (cardiac involvement, gastroenteritis)
- Constitutional symptoms occur in both subgroups during active vasculitis
Clinical Pitfall
Beware of rare GPA/EGPA overlap cases 78. Some patients present with features of both diseases (GPA with eosinophilia), which can complicate diagnosis. However, these represent outliers rather than typical presentations. The presence of significant eosinophilia, asthma, and prominent constitutional symptoms during active disease should raise suspicion for EGPA over GPA.