Rheumatology Flashcards
What is the single most important diagnostic test in the inflamed joint?
arthrocentesis
A swollen, single joint: DDx until proven otherwise
septic arthritis
Septic arthritis: labs/Dx, DDx
Arthrocentesis
- Hold ABx until procedure completed
- do not perform on a prosthetic joint unless you talk to ortho first
DDx:
- trauma?
- underlying joint disease? Monoarthritis or poly arthritis?
- septic arthritis is almost always monoarticular, except if gonococcal
Risk factors for septic arthritis
Age >80
DM
prosthetic joints
skin infection overlying or close to the joint affected
known abnormal joint (e.g. rheumatoid joint)
septic arthritis: management
Blood cultures before ABx are given
ABx
- vancomycin - given empirically until culture data returns
- beta-lactam - given for gram negative (good penetrance into the synovium)
Surgery: wash out
- consult ortho surgery ASAP
Echocardiogram to assess for valvular vegetations
ABx for several weeks
- often nafcillin or oxacillin
If gonorrhea is suspected: genital NAAT
If Dx is uncertain: consult rheum to assist with management
gouty arthritis
acute monarticular inflammatory arthritis, most often the 1st MTP
Recurrence is common
Metabolic disease, where there is deposition of uric acid crystals in the tissues (synovium has a high affinity for this)
- caused by either overproduction or under excretion of uric acid
gouty arthritis: diagnosis
Joint fluid aspiration is the gold standard
identification of crystals with polarized light microscopy of the synovial fluid
- gout: monosodium urate crystals
- pseudogout: calcium pyrophosphate
Often based on clinical exam and history
Measuring the uric acid level is unreliable
primary gout
highly heritable
common in Pacific Islanders
Involves the underexcretion of uric acid
secondary gout: risk factors
Risk factors:
- hospitalized patients with high doses of diuretics
- kidney disease
- myeloma
- etoh
- consuming large amounts of purines (meats, gravies, foods with high yeast content)
gouty arthritis: S/Sx, imaging
Onset of an acute attack is typically sudden and nocturnal
Joint: hot, red, swollen, allodynia (light touch is exceedingly painful)
May have low grade fever
XR:
- joint space narrowing
- erosion
- soft tissue swelling
gouty arthritis: common precipitants
consumption of alcohol (specifically beer)
changes in medications (specifically diuretics)
fasting
gouty arthritis: treatment
NSAIDs
- if tolerated, full doses for 7-10 days
Colchicine:
- 1.2mg loading dose, followed by 0.6mg 1 hour later, then 0.6mg Q12h x14d
- often causes diarrhea
- adjust for CKD, risk for rhabdomylosis
Steroids
- for those who cannot tolerate NSAIDs
- dramatic effect (often within 1 hour)
gouty arthritis: management between attacks
Diet
- reduce purine consumption
- reduce EtOH intake
Medications
- avoid hyperuricemic medications (e.g. thiazide or loop diuretics)
Reduction of uric acid level
- allopurinol: 100mg/day, then titrated weekly until the uric acid level is <6.0; Never start during an attack, as it will cause paradoxical worsening of the attack
- febuxostat: 40mg/day, then titrated weekly until the uric acid level is <6.0; generally used in those who cannot tolerate allopurinol
axial spondyloarthritis
Formerly known as ankylosing spondylitis (ax-SpA)
Potentially disabling inflammatory arthritis of the spine, usually presenting as chronic back pain, almost always before the age of 45
axial spondyloarthritis: S/Sx, imaging
Lower back pain and stiffness that is typically worse at night and better upon rising
Xray: looks like bamboo
axial spondyloarthritis: treatment
NSAIDs
- helpful in mild cases
DMARDs
- biologics: TNF-inhibitors (etanercept), IL-17 monoclonal antibodies (drugs that end in -ab)
- small molecules (drugs that end in -ib)
reactive arthritis
A syndrome of large, weight bearing joint arthritis, and often extra-articular manifestations of conjunctivitis (or uveitis) and urethritis
“can’t see, can’t pee, can’t climb a tree”
reactive arthritis: presentation
Follows certain infections by about 1-4 weeks
- often follows GI infections (Shigella, Salmonella, Yersinia, or Campylobacter)
- some STDs (Chlamydia)
- some streptococcal infections
Systemic Lupus Erythematosus
A systemic inflammatory multi system disease, characterized by autoantibodies to nuclear antigens
Anti-nuclear antibodies (ANA)
Seen in 95% of SLE but not specific for SLE
Once this is found to be positive, no need to ever check it again
Anti-Smith (Anti-Sm)
Seen in 10-30% of SLE, but rarely seen with anything else; very highly specific for SLE
ANCA
highly specific for granulomatosis with polyangiitis
Systemic Lupus Erythematosus: treatment
Hydroxychloroquine (Plaquenil)
- essentially all cases of SLE should be on this
Corticosteroids (e.g. prednisone or methylprednisolone)
- especially helpful to manage a flare up of symptoms
Methotrexate
Azatioprine (Imuran)
Mycophenylate Mofetil (Cellcept)
Cyclophosphamide (Cytoxan)
Belimumab (Benlysta)
Voclosporine (Lupkynis)
CREST Syndrome
Calcinosis
Raynaud’s phenomenon
Esophageal dysmotility
Sclerodactyly
Telangiectasias
