A 55-year-old man with longstanding seropositive RA develops symmetrical peripheral neuropathy, weight loss, skin nodules, and mononeuritis multiplex. ANA is negative; ANCA (p-ANCA, anti-MPO) is positive at high titre. The MOST likely diagnosis is:

• A Felty's syndrome
• B Microscopic polyangiitis complicating RA
• C Rheumatoid vasculitis ✓
• D Amyloid neuropathy secondary to chronic RA inflammation

Explanation

Rheumatoid vasculitis is a severe extra-articular manifestation of longstanding seropositive (high-titre RF/anti-CCP) RA. It presents with mononeuritis multiplex, digital infarcts, leg ulcers, and systemic features. ANCA (typically p-ANCA/anti-MPO) can be positive in up to 30% of rheumatoid vasculitis cases. Felty's syndrome is splenomegaly + neutropenia in RA. AAV occurring de novo alongside RA is less common than vasculitis as an extra-articular manifestation of RA itself.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.