- Affects 1% of population
- o Immunological disease triggered by environmental factors in pts with genetic predisposition. Exacerbations / remissions are common.
- o Refer early as early DMARDs tx can significantly improve outcome.
- P/c: middle age, female, often gradual/can be acute onset, symmetrical peripheral joint pain/stiffness/swelling/loss of function, effusions and swellings, early morning stiffness. Damage and deformity happen later – irreversible. Unusual presentations: monoarthritis, migratory, PMR-like illness, systemic with fatigue.
- Key features:
- o Hands: ulnar deviation, z-deformity of fingers (boutonniere deformity [flexed PIP, hyperextended DIP] and swan neck deformity [hyperextended PIP and flexed DIP]).
- o Legs/feet: subluxation of metatarsal haeds in feet, claw toes, bakers cysts at knee.
- o Spine: cervical subluxation, atlanto-axial instability = cord compression.
- o Non-articular features: weight loss, fever, rheumatoid nodules (extensor surfaces of forearms), vasculitis, sjogrens syndrome and scleritis, pleural effusions, lung nodules (Caplans: RA nodules AND pneumoconiosis), pericarditis, MV disease, skin changes, nerve entrapment and peripheral neuropathies, Felty’s syndrome = RA, splenomegaly, leucopenia (hypersplenismanaemiathrombocytopaenia).
- Differentials: psoriatic arthritis, nodal OA, SLE, bilateral carpal tunnel, CTDs, PMR.
- Ix: FBC (anaemia), ESR/CRP, plts, WCC, Rheumatoid factor and anti-CCP antibodies are +ve in majority. A minority have +ve ANA titre. Xray: loss of joint space/erosions/destruction in late disease.
- Complications: depressin, OA, infections, lymphoma, CVD, amyloidosis (10%).
- Mx: general support/advice, OT, physio, strapping/mobility,
- o NSAIDs and analgesics: paracetamol, NSAID response varies (start low: 200-400mg ibuprofen TDS = least gastric toxic), can increase to diclofenac 50mg. If known gastric problems – add gastric protection (misoprostol, PPI, celecoxib 100mg bd)
- o Cortsicosteroids: Kenbalog intra-articluar injection max use 3x/year. Depots and oral steroids less used.
- o DMARDs: methotrexate, sulfasalazine, penicillamine, gold, azathioprine, leflunomide, ciclosporin, cyclophosphamide, cytokine inhibitors (etanercept, infliximab)… used under consultant supervision only. Need to be started early 3-6/12 of diagnosis. May take several months to take effect. Before starting check baseline bloods = U&E, LFTs, FBC, urinalysis.
- o Surgery: careful balance. Joint fusion, replacement, tendon transfer and repair, decompression.