Is vasculitis considered a rheumatologic disorder?

Is Vasculitis a Rheumatological Problem?

Yes, vasculitis is definitively a rheumatologic disorder, with rheumatologists serving as the primary specialists for diagnosis and management of most forms of systemic vasculitis. 1

Rheumatology as the Primary Specialty

The American College of Rheumatology (ACR) and European League Against Rheumatism (EULAR) have established themselves as the leading authorities on vasculitis management, developing comprehensive classification criteria and treatment guidelines for these conditions. 1 The 2021 ACR/Vasculitis Foundation guideline explicitly positions rheumatologists as the core specialists, with the voting panel comprising 9 adult rheumatologists and 5 pediatric rheumatologists who formulated evidence-based recommendations for vasculitis management. 1

Vasculitis falls squarely within the rheumatologic domain because it represents an autoimmune inflammatory process affecting blood vessels, sharing pathophysiologic mechanisms with other autoimmune rheumatic diseases. 2, 3

Classification Systems Developed by Rheumatology

The ACR classification criteria and Chapel Hill Consensus Conference (CHCC) nomenclature are the most widely used systems to distinguish different forms of vasculitis, both developed and endorsed by rheumatology organizations. 1, 3 These classification systems categorize vasculitis based on:

• Vessel size involvement (large, medium, and small vessels) 1, 4
• Primary versus secondary vasculitis 1, 5
• Presence of specific autoantibodies (particularly ANCA) 1, 6

Autoimmune Pathophysiology

Vasculitis represents an autoimmune inflammatory process with mechanisms similar to other rheumatologic conditions. 1, 2 The pathophysiology involves:

• Autoantibody-mediated vascular injury, particularly ANCA in granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA) 1, 6
• Immune complex deposition in vessel walls 2, 7
• T-cell mediated endothelial activation and vascular inflammation 2
• Complement system activation leading to vessel wall damage 2

Overlap with Other Rheumatologic Diseases

Vasculitis frequently occurs as a manifestation of established autoimmune rheumatic diseases, further cementing its place within rheumatology. 2, 7, 8 Secondary vasculitis can complicate:

• Rheumatoid arthritis (rheumatoid vasculitis) 7, 8
• Systemic lupus erythematosus 5, 8
• Sjögren's syndrome 8

These associations demonstrate that vasculitis shares common immunologic mechanisms with core rheumatologic conditions. 2

Multidisciplinary Involvement Does Not Diminish Rheumatologic Primacy

While other specialists contribute to vasculitis care depending on organ involvement (nephrologists for glomerulonephritis, pulmonologists for alveolar hemorrhage, otolaryngologists for sinonasal disease), rheumatologists maintain primary responsibility for diagnosis, classification, and systemic immunosuppressive management. 1

The 2021 ACR guideline explicitly notes that while the literature review team chair was a nephrologist, the voting panel was intentionally composed primarily of rheumatologists who could provide insight across all forms of vasculitis. 1 Other subspecialists (like pulmonologists) were not included because they lack experience with the full spectrum of vasculitic diseases. 1

Treatment Paradigms Follow Rheumatologic Principles

The therapeutic approach to vasculitis mirrors treatment strategies for other autoimmune rheumatic diseases:

• Glucocorticoids as primary therapy 3
• Conventional immunosuppressants (methotrexate, cyclophosphamide, azathioprine) 7, 3
• Biologic therapies (rituximab, TNF inhibitors) used in rheumatologic conditions 7, 3
• Remission induction and maintenance strategies similar to other rheumatic diseases 1

Common Pitfalls

A critical caveat: Do not confuse single-organ vasculitis (like isolated cutaneous vasculitis) with localized forms of systemic vasculitis (like GPA or EGPA) that may initially present with limited manifestations but can progress to systemic disease. 1 The latter requires rheumatologic evaluation and systemic immunosuppression, while the former may be managed by dermatologists with conservative measures. 7

Another pitfall: Secondary vasculitis triggered by infections, drugs, or malignancy requires identification and treatment of the underlying cause, but still benefits from rheumatologic consultation for immunosuppressive management when severe. 5, 7, 8