Localized polyartheritis nodosa in the lower limb with new bone formation

Area of Science:

• Rheumatology
• Immunology
• Vascular Medicine

Background:

• Ankylosing spondylitis is a chronic inflammatory disease primarily affecting the spine.
• Vascular manifestations are uncommon in ankylosing spondylitis, particularly in a burned-out state.

Observation:

• A 61-year-old male with inactive ankylosing spondylitis presented with polyarteritis affecting the right lower limb.
• The condition was associated with new bone formation on the tibia and fibula.

Findings:

• The polyarteritis and periosteal new bone formation may have been precipitated by a Yersinia infection.
• Human Leukocyte Antigen (HLA) typing revealed A 28, 26, B5, 27, Cwl.

Implications:

• This case highlights a potential link between Yersinia infection and vasculitis in patients with ankylosing spondylitis.
• It underscores the importance of considering infectious triggers for vascular complications in rheumatologic patients.