Question

A 45-year-old woman with long-standing rheumatoid arthritis (RA) develops numbness, paresthesia, non-healing leg ulcers, and absent ankle reflexes. She is on regular RA treatment. What is the most probable diagnosis?

• A. RA-associated vasculitis
• B. Drug-induced peripheral neuropathy
• C. Rheumatoid myelopathy
• D. Amyloid neuropathy

Hint:

Rheumatoid Vasculitis is considered a severe, life-threatening complication and requires aggressive systemic immunosuppression, often with high-dose corticosteroids combined with Cyclophosphamide or Rituximab, rather than simple modification of standard DMARDs.

Answer 1

The Correct Option is A

Concept:
Rheumatoid Arthritis (RA) is primarily a destructive polyarticular joint disease, but long-standing, severe, seropositive RA frequently develops significant extra-articular systemic manifestations.
The combination of sensory neurological deficits (neuropathy) and deep cutaneous ischemic lesions (ulcers) points to a vascular pathogenesis.
Explanation:
• Rheumatoid Vasculitis (RV) is a rare but serious extra-articular complication of RA, typically seen in patients with a long history ($>$ 10 years) of severe, erosive, seropositive disease (high titers of Rheumatoid Factor).

• It is an immune-complex mediated inflammation of small and medium-sized arteries.

• Clinically, RV most frequently targets the skin and the peripheral nervous system.

• Cutaneous involvement typically manifests as deep, painful, non-healing ischemic ulcers on the lower extremities, digital infarcts, or palpable purpura.

• Neurological involvement is due to vasculitis of the vasa nervorum (the tiny blood vessels supplying peripheral nerves), resulting in nerve ischemia. This presents as sensory polyneuropathy (numbness, paresthesias, absent reflexes in the distal legs) or mononeuritis multiplex (e.g., sudden foot drop or wrist drop).

• Option (B), Drug-induced neuropathy, could explain the sensory symptoms but would not account for the classic vasculitic non-healing leg ulcers.

• Option (C), Rheumatoid myelopathy, involves compression of the spinal cord (usually at the cervical level due to atlantoaxial subluxation). It presents with upper motor neuron signs (hyperreflexia, spasticity, weakness), not isolated absent distal ankle reflexes and skin ulcers.

• Option (D), Amyloid neuropathy, is possible in chronic inflammatory states but is less common and less likely to present simultaneously with classic deep vasculitic leg ulcers.
Final answer:
The presence of non-healing leg ulcers combined with peripheral neuropathy in long-standing RA is the classic presentation of RA-associated vasculitis.