## Extra-Articular Manifestations of Rheumatoid Arthritis **Key Point:** Extra-articular manifestations (EAM) occur in 15–30% of RA patients and correlate with disease severity, seropositivity, and smoking history. ### Common EAM in RA | Manifestation | Frequency | Pathology | Clinical Features | |---|---|---|---| | Rheumatoid nodules | 20–30% | Subcutaneous granulomas | Firm, non-tender, over elbows, fingers, pressure points | | Interstitial lung disease | 10–15% | Pulmonary fibrosis | Dyspnea, restrictive pattern, ↓ DLCO | | Secondary Sjögren's | 10–15% | Lymphocytic infiltration of salivary/lacrimal glands | Dry mouth, dry eyes, positive anti-SSA/Ro | | Rheumatoid vasculitis | 1–5% | Small/medium vessel inflammation | Cutaneous ulcers, digital infarcts, mononeuritis multiplex | | Felty syndrome | 1–3% | Splenomegaly + neutropenia | Hepatosplenomegaly, infections | **High-Yield:** Acute necrotizing vasculitis affecting **medium-sized arteries** is NOT a typical EAM of RA. When vasculitis occurs in RA, it predominantly affects **small vessels** (cutaneous, digital, peripheral nerves), causing: - Cutaneous ulcers and digital infarcts - Mononeuritis multiplex - Scleritis and episcleritis Medium-sized artery necrotizing vasculitis is the hallmark of **polyarteritis nodosa (PAN)**, not RA. RA-associated vasculitis is a small-vessel process. **Clinical Pearl:** Rheumatoid vasculitis is rare but serious, occurring almost exclusively in long-standing, seropositive disease with high disease activity. It is a marker of poor prognosis and requires aggressive immunosuppression. **Warning:** Do not confuse RA vasculitis (small vessel, cutaneous/digital) with PAN (medium vessel, visceral involvement, hepatitis B association).
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