Four distinct clinical phenotypes of vasculitis affecting medium-sized arteries

Area of Science:

• Rheumatology
• Vasculitis Research
• Internal Medicine

Background:

• Polyarteritis nodosa (PAN) includes cutaneous (cPAN) and systemic forms.
• Severe cPAN presents with ulcers, necrosis, or neuritis, often challenging to distinguish from systemic PAN.
• Understanding distinct clinical phenotypes is vital for effective treatment strategies.

Purpose of the Study:

• To evaluate the clinical characteristics of patients diagnosed with necrotizing arteritis of medium-sized arteries.
• To differentiate between mild cPAN, severe cPAN (ulcer/neuritis types), and systemic PAN.
• To identify key differences in presentation, treatment, and outcomes.

Main Methods:

• Retrospective analysis of 41 patients diagnosed with necrotizing arteritis between 2008-2017.
• Evaluation of clinical data, laboratory findings, treatment regimens, relapse rates, and mortality.
• Classification of patients into mild cPAN, severe cPAN (ulcer/neuritis), and systemic PAN groups.

Main Results:

• 36 patients had cPAN (15 mild, 9 ulcer, 8 neuritis, 4 both); 5 had systemic vasculitis.
• Mild cPAN showed female predominance and younger age; systemic PAN had older age and higher inflammatory markers.
• Severe cPAN (ulcer type) exhibited significantly higher relapse rates (88.9%) compared to other groups.

Conclusions:

• Distinct clinical characteristics were identified for mild cPAN, severe cPAN (ulcer/neuritis types), and systemic PAN.
• Severe cPAN, especially the ulcer type, requires aggressive management due to high relapse rates.
• Combination therapy is indicated for severe cPAN (ulcer type) to improve outcomes.