Musculoskeletal
Systemic Lupus Erythematosus
Autoimmune inflammatory condition caused by antibody-antigen deposition in various tissues.
- H&P: Young women, blacks, hispanics, asians
- Dx: DOPAMINe RASH 4 of 11 criteria, rule out 2° causes (drug-induced lupus SHIPP: sulfonamides, hydralazine, isoniazid, phenytoin, procainamide). Best screening test is ANA (98% sensitivity), most specific are anti ds-DNA, anti-Sm. Complement C3 and C4 levels can also be low, especially during acute flares.
- Tx: NSAIDs for arthritis and mild serositis; hydroxychloroquine for skin and renal disease; for moderate to severe disease, use corticosteroids or anti B cell biologics; for acute flares, use steroid tapers. Test for anti-SSA in patients thinking about getting pregnant, as this antibody can cross the placenta and cause neonatal lupus and complete heart block. If patient has anti-phospholipid antibody syndrome, they need lifelong warfarin.
Rheumatoid Arthritis
- H&P: middle aged women, HLA-DR4 serotype; morning stiffness that lasts > 30 min and improves with activity; Swan Neck deformity (PIP extension, DIP flexion), Boutonniere deformity (PIP flexion, DIP extension), ulnar deviation of MCP.
- Dx: 4 criteria for 6+ weeks. 3 or more joints (PIP, MCP, wrist, elbow, knee, ankle); symmetrical joint synovial hypertrophy with cartilage loss and osteoporosis on xray; elevated CRP, ESR (sensitive, not specific), rheumatoid factor (75% sensitive), or anti-CCP (most specific); inflammatory synovial fluid on joint aspiration; rheumatoid skin nodules (elbow most common).
- Tx: NSAIDs and PT; Sulfasalazine, Hydroxychloroquine, or Glucocorticoids for milds disease; Methotrexate, anti-TNF biologics, or corticosteroids for moderate-severe disease; anti-TNF biologics AND corticosteroids for severe disease. Avoid methotrexate in patients with HIV, liver disease, ILD, renal disease, pregnancy, or bone marrow suppression; avoid anti-TNF in patients with TB.
Osteoarthritis
- H&P: Older patients; polyarticular arthritis in the DIP (Heberden), PIP (Bouchard), 1st CMC, elbow, hip, knee, and back; Morning stiffness lasts < 30 min, but pain worsens with activity as the day progresses; can be secondary to trauma or metabolic disease (Wilson or Hemochromatosis)
- Dx: Xrays and clinical findings asymmetric joint sclerosis, narrowing, periarticular bone spurs; inflammatory lab markers are normal; joint aspiration has WBCs < 2000
- Tx: Exercise, PT, weight loss; NSAIDs, APAP; Glucocorticoid injections; Joint replacement.
Gout
- H&P: Monoarthritis, swollen, red, very painful joint, most commonly the first carpometatarsal joint; can be associated with tophi if chronic; risk factors include obesity, male, Pacific Islanders, cancer, renal disease, Thiazide diuretic use, and high meat/alcohol consumption.
- Dx: Joint aspirate reveals negatively birefringent needle shaped monosodium urate crystals that are yellow with parallel light, with WBCs 3-50k. Differential diagnosis of monoarthritis includes pseudogout (rhomboid shaped, positively birefringent, calcium pyrophosphate crystals), septic arthritis, trauma, reactive arthritis, Hemochromatosis, and Lyme disease.
- Tx: First-line is high-dose NSAIDs (e.g. Indomethacin, but avoid in ESRD) or colchicine, second-line is intra-articular corticocorticoids. Give allopurinol once the acute symptoms resolve to prevent recurrences.
Low Back Pain
- H&P
- Dx
- Tx
Spondyloarthropathies
Ankylosing Spondylitis
Reactive Arthritis
Psoriatic Arthritis
Vasculitides
Temporal Arteritis
Polyarteritis Nodosa
Polymyalgia Rheumatica
Fibromyalgia
- H&P: Older women, history of depression or trauma, or IBS; widespread chronic muscle pain in pre-defined areas, insomnia, weakness, fatigue
- Dx: WPI 3-6 and SSI > 9, or WPI ≥ 7 and SSI ≥ 5, labs are all negative
- Tx: TCAs, SSRIs, Gabapentin, Pregabalin, exercise, PT, hydrotherapy, heat, pain psych
Polymyositis and Dermatomyositis
Scleroderma
Missed Concepts
- Hemochromatosis diagnosis and association with HCC
- Paget disease diagnosis
- Complications of untreated scaphoid fracture
- Chronic exertional compartment syndrome vs. tibial stress fracture vs. shin splints
- Myotonic dystrophy diagnosis
- Diagnosis of Chlamydia