Rheumatology Flashcards
Questions to ask about a patient with musculoskeletal complaints
- inert vs contractile structures (articular/extra-articular)?
- inflammatory vs non-inflammatory?
- duration and distribution?
- extra-articular manifestations/complications?
- could it be referred pain?
Describe the capsular pattern of arthritis with reference to the shoulder and hip
Shoulder: limited external rotation and abduction
Hip: limited internal rotation and adduction
Signs of pain being inflammatory (rather than non-inflammatory)
- morning stiffness for > 1 hour
- prominent night-time symptoms
- exercise improves/ rest worsens sx
- good response to NSAIDS
- constitutional symptoms
- systemic manifestations
What is the compression test and explain its relevance
Slight pressure across carpal/tarsal joints
–> elicits pain in synovitis
Etiology of Rheumatoid Arthritis
- genetics (HLA)
- sex (females)
- environmental (smoking, stress, infection)
Inflammatory cytokines involved in RA
- Tumour necrosis factor
- Interleukin-1
- Interleukin-6
Typical hx of RA
Young female Insidious onset Pain Early morning stiffness of several hours Hands and wrists Constitutional symptoms (fatigue, lethargy, fever)
Joint distribution of RA
COMMON wrists, MCPJ, PIPJ, MTPJ, knees, ankles LESS COMMON elbows, C1/C2, shoulders, hips RARE crico-arytenoid, temperomandibular
Early RA of hands
- boggy tender swellings around MCP and PIP
- filling of valleys between MCPs
- spindling of fingers due to fusiform swelling of PIPs
- loss of fist/ loss of grip strength (tenosynovitis)
- swelling over wrist dorsum
- wasting of small hand muscles
Advanced RA of hands
- Swan neck deformity
- Boutonniere deformity
- Z deformity of thumb
- ulnar deviation
- subluxation and dislocation of MCPJ
Poor prognostic signs in RA
- early appearance of erosions
- RF/ACPA positivity
- rheumatoid nodules
Extra-articular manifestations in RA
- Peri-articular: rheumatoid nodules, tenosynovitis
- Eyes: scleritis, sicca
- Lung: pleurisy, fibrosis, nodules
- Cardiac: effusions, atherosclerosis
- Skin: leg ulcers (vasculitis)
- Neurological: carpal tunnel, cervical myelopathy
- Haematological: Anaemia, Felty’s Syndrome
Felty’s syndrome
- RA
- Splenomegaly
- Neutropenia
- -> susceptible to infection
- -> associated with severe disease
Special Investigations for RA
- FBC
- ESR/CRP
- RF
- ACPA
- Synovial fluid
- Radiology
X-rays of early RA
- soft tissue swelling
- peri-articular osteopaenia
- erosions at margins of small joints
[U/S better at picking up erosions and tenosynovitis but time-consuming)
Medical Rx of RA
- DMARDs: methotrexate (mainstay), sulfasalazine, chloroquine
- Biologics (against TNFa, IL-6, B-lymphocytes)
- Steroids
- Anti-inflammatories (diclofenac, ibuprofen, indomethacin)
- Analgesics (paracetamol, amitriptyline)
Indications for joint replacement in RA
- pain due to joint damage not responding to medical management
- improvement of function/ restoration of movement
Causes of Mono-Arthritis
- septic arthritis
- trauma (fracture, internal derangement, haemarthrosis)
- crystal deposition disease
- osteoarthritis
- juvenile idiopathic arthritis
- coagulopathy
- AVN
Polyarthritides that can present with mono-articular onset
RA JIA Viral arthritis sarcoid reactive arthritis psoriatic arthritis enteropathic arthritis
Contents of synovial fluid analysis
- gram stain/culture (infection)
- crystals (gout/pseudogout)
- blood (haemarthrosis)
- WCC (2k-50k = inflammatory; >50k = pyarthrosis)
Diagnostic studies in monoarthritis
ALWAYS - Xray - FBC and Diff - Uric acid (may be low in acute gout!) SELECTED - blood/urine cultures - clotting profile - ESR RARELY - serology (RF, ANF)
Diagnositic studies in chronic monoarthritis
- arthroscopy
- MRI
- bone scan
Aetiology of Osteoarthritis
- Primary - localised/generalised
- Developmental - DDH, Perthe’s, SUFE
- Traumatic - fx, occupational strain, internal derangement)
- Inflammatory (septic arthritis, TB, RA)
- Metabolic (crystal arthritis, haemochromatosis, alkaptonuria)
- Endocrine (acromegaly, DM, hypothyroidism, obesity)
Symptoms of OA
Mechanical pain
Stiffness 15-30 minutes
Muscle spasm
Joints of OA
COMMON DIP, PIP, 1st carpometacarpal, acromioclavicular, knees, hips, spine, 1st MTP ATYPICAL wrists, elbow, gleno-humeral, ankles, MCPs, MTP 2-5
Signs of OA
- Swelling of OA joints - firm, bony
- Tenderness at joint margin
- Crepitus
- Warmth
- Osteophytes
- Limitation of function and mobility
- Periarticular muscle atrophy
Radiology of OA
- typical joint involvement
- loss of joint space
- osteophyte formation (spurs)
- subchondral sclerosis
- bone cysts
- malalignment/ deformity
- gull wing sign in PIP and DIP
Treatment of OA
- Weight loss
- Exercise
- Heat/massage
- Simple analgesics
- NSAIDS
- Intra-articular corticosteroids
- Osteotomy
- Arthroplasty
- Dietary supplements
Indications for arthroplasy in OA
- severe unresponsive pain (cannot stand in place for 20-30 minutes)
- loss of joint function
Important crystals in arthropathies
Uric acid –> gout
Calcium pyrophosphate –> pseudogout
Calcium hydroxyapatite –> calcifying peri-arthritis
Where does uric acid come from
10-30% dietary purines
60-90% liver
Where is uric acid excreted
75% renal
25% intestinal
Define gout
inflammatory reaction in synovial joints and/or periarticular tissues due to deposition of urate crystals due to hyperuricaemia
Aetiology of Hyperuricaemia
PRIMARY
- overproduction (enzyme abnormalities)
- decreased secretion (low GFR, tubular issues)
- combination of above
SECONDARY
- Drugs (reduce renal excretion)
- Overproduction
- Underexcretion
Drugs causing hyperuricaemia
Cyclosporine Alcohol Nicotinic Acid Thiazides Lasix Ethambutol Aspirin Pyrazinamide
Secondary overproduction of uric acid
Purine rich foods Myelo/Lymphoproliferative disorders Psoriasis Obesity Fructose ingestion
Secondary underexcretion of uric acid
keto-acidosis lactate acidosis renal disease polycystic kidneys lead nephropathy hyperparathyroidism hypothyroidism
DDX for Gout
- cellulitis
- septic arthritis
- pseudogout
Diagnosis of Gout
- Serum uric acid (may be normal)
- Synovial fluid microscopy (crystals under polarised light)
- XRay: Soft tissue swelling
Common sites of gout tophi
Olecranon 1st MTPJ Earlobes Tendons Peri-articular
Mx of acute gout
- Colchecine 0.5mg stat and then 2-3 times daily
- NSAID eg. voltaren, indocid, other (check renal function)
- Corticosteroids: prednisone 0.5mg/kg
Mx of interval/chronic gout
- remove precipitating factors
2. determine kidney function
Indications for uric acid lowering therapy
- > 3 acute attacks per year
- tophi
- bony/cartilage destruction on X-ray
- gout with renal disease
- uric acid kidney stones
- uric acid >0.54mmol/l
Uric acid lowering drugs
- uricosuric: probenecid
- xantine oxidase inhibitors: allopurinol
- other: lisinopril, losartan, oxypurinol, uricase, citrosoda
Probenecid contraindications
- kidney stones
2. renal impairment
Side effects of allopurinol
- skin reactions
- GIT symptoms
- bone marrow suppression
- precipitate acute gout