AKT · Musculoskeletal/Inflammatory arthritis

Rheumatoid arthritis

Chronic autoimmune symmetrical inflammatory polyarthritis (anti-CCP / rheumatoid factor)

Overview

A chronic, symmetrical, deforming inflammatory polyarthritis driven by autoimmune synovitis, with extra-articular features. Early diagnosis and early DMARD therapy (treat-to-target) prevent joint destruction. Anti-CCP is the most specific antibody; the small joints of the hands and feet are affected first, with morning stiffness lasting over an hour.

Recognise

Symmetrical pain, swelling and early-morning stiffness (>1 h) of the small joints — MCPs, PIPs, wrists, MTPs (DIPs spared)
Late deformities: ulnar deviation, swan-neck, boutonnière, Z-thumb; rheumatoid nodules
Extra-articular: nodules, ILD, pleural/pericardial effusions, scleritis/episcleritis, Felty syndrome (RA + splenomegaly + neutropenia), AA amyloid, carpal tunnel

Red flags

Atlanto-axial subluxation (neck instability) — caution before intubation/anaesthesia; cord compression
Septic arthritis can complicate an RA joint — a single hot swollen joint out of keeping = aspirate

Differentials & how to tell them apart

OsteoarthritisDIP/weight-bearing joints, worse with use, short-lived stiffness, no systemic inflammation, Heberden/Bouchard nodes

Psoriatic arthritisDIP involvement, dactylitis, psoriasis/nail pitting, often RF-negative

SLE / viral arthritisnon-erosive; multisystem autoantibodies (SLE) or self-limiting (parvovirus)

Polymyalgia rheumaticaproximal girdle stiffness in the elderly, no true synovitis/erosions

Rheumatoid arthritis — ulnar deviation and small-joint deformity of the hands
Prashanthns / CC BY-SA 3.0 — Wikimedia Commons

Investigations

Anti-CCP (most specific) and rheumatoid factor; raised ESR/CRP; X-rays (soft-tissue swelling, periarticular osteopenia, joint-space narrowing, marginal erosions, deformity); ultrasound/MRI for early synovitis; baseline FBC/U&E/LFTs before DMARDs.

Management

Methotrexate (first-line DMARD) + folic acid, treat-to-target, with a bridging steroid

1Refer early to rheumatology. Start a conventional DMARD as soon as diagnosis is made — methotrexate first-line with folic acid — and treat-to-target (escalate to control disease activity). Use a short bridging corticosteroid for flares.Gate: Before anti-TNF/biologic therapy, SCREEN for latent TB and hepatitis B/C (reactivation risk); methotrexate is contraindicated in pregnancy and needs the trimethoprim interaction avoided.
2Inadequate response to ≥2 conventional DMARDs → biologic or targeted synthetic DMARD (anti-TNF, rituximab, IL-6 or JAK inhibitor). MDT: physio/OT, surgery for severe joint damage.

Start a conventional DMARD ASAP — methotrexate first-line (+ folic acid) — treat-to-target; early DMARD prevents erosion; add hydroxychloroquine/sulfasalazine/leflunomide as needed

Short-term bridging corticosteroid (oral/IM/intra-articular) — controls flares while the DMARD takes effect

Biologic / targeted DMARD (anti-TNF, rituximab, JAK inhibitor) — if inadequate response to ≥2 csDMARDs; screen for TB/hepatitis before anti-TNF

NSAID + PPI for symptom relief — symptomatic only; does not alter disease course

Key points

Symmetrical small-joint synovitis with >1 h morning stiffness + anti-CCP/RF + marginal erosions = RA → early methotrexate, treat-to-target. Screen TB/hepatitis before anti-TNF. Watch atlanto-axial instability pre-anaesthesia and a single hot joint (septic arthritis).

Monitor & prognosis

Disease activity (DAS28), FBC/LFTs on methotrexate, CXR for ILD; annual CV risk (RA raises it).

Early DMARD therapy markedly improves outcomes; untreated disease causes irreversible joint destruction.

Source: NICE NG100 (rheumatoid arthritis)