Micro-crystalline Arthropathies Lecture Powerpoint Flashcards
Some common crystal arthropathies (3)
- gout
- calcium pyrophosphate dihydrate disease (CPPD)
- cacium apatite crystals
Gout definition and epidemiology
Clinical syndrome resulting from deposition of monosodium urate crystals, yperuricemia is found in up to 17% of population but not all get gout, typcially presents in men between age 30-50 with prevalance increasing, rare in premenopausal women (estrogen removees uric acid thru kidneys)
4 stages of gout
- Asymptomatic hyperuricemia
- Acute gouty arthritis
- Intercritical gout
- Chronic tophaceous gout
Asymptomatic hyperuricemia
1st stage of gout, At puberty serum urate concentration sincrease, but most men with hyperuricemia remain asymptomatic thruout life, rate of gout and nephrolithiasis increases with level of hyperuricemia, often requires 15-20 years of sustained hyuperuricemia before acute attack, no need to treat hyperuricemia with meds unless uric acid very high >13,
Asymptomatic hyperuricemia patient considerations
- is patient obese
- alcohol usage
- thiazide diuretics or aspirin usage
- renal disease
- myeloproliferative dz
- lead exposure
Acute gouty arthritis
2nd stage of gout, peak onset 30-50 years of age in men, occurs in postmenopausal women (estrogen causes uricosuria), abrupt onset, may last for several days (should still treat in interim), typically monoarthritis in 85-90% of cases but some present with pauciarticular(oligo) involvement, MTP most common joint affected but can also see midfoot, ankle, knee, wrist, etc. but more common in lower extremity
Yellow subcutaneous nodules even in absence of podagra (inflammation of first mcp joint) tapped for uric acid crystals can be indicative of…
…gout
Acute gouty arthritis
3rd stage of gout, typically precipitated by surgery, trauma, medical illness, alcohol/aspirin/diuretics/cyclosporine use, dietary excess,anything that causes sudden hyperuricemia
Acute gouty arthritis diagnosis (3)
- aspirate joint and needle shaped crystals,
- don’t rely on serum uric acid levelor joint involved
- don’t be fooled by leukocytosis, fever, skin erythema, synovial fluid WBC, etc
Urate crystal appearance on histological slide
-needle shaped, often larger than WBC’s, depending on angle light hits determines color which is variable
Acute gouty arthritis treatment options (3)
- NSAIDS such as indomethacin, naproxen
- steroids oral or intraarticular
- colchicine
Intercritical period of gout
Symptom free period of gout between attacks (either self resolved or treated), sometimes second attack never occurs, but 62% of time recurrence within 1 year, 78% of time within 2 years, with time between attacks usually shortening
Gout intercritical period treatment
- weight control
- sometimes initiate chronic pharmacologic therapy
- avoidance of foods high in purine
- avoid aspirin and thiazide diuretics
- educate regarding eval and treatment of 2nd attack
Acute gouty attacks order of treatment for repeating offenses
- After first attack educate, might not begin urate lowering therapy
- if 2nd attack occurs begin chronic urate lowering therapy alongsisde prophylaxis with NSAID or low dose prednisone or colchicine, after one week gradually add in ULT (allopurinol at 100mg) (never start ULT during acute attack), repeat uric acid level and titrate upwards every 2-5 weeks, average allopurinol dose is 300mg but can be higher even in cases of renal impairment, goal to reach serum uric acid <6mg/dL, prophylaxis stopped after reaching goal, remain on ULT for life
Chronic pharm treatment of gout (Urate lowering thearpy)
- Probenecid, used in under excreters (24 hr urine uric acid less than 600mg)
- xanthine oxidase inhibiotrs (allopurinol) for over producers (24 hr uric acid greater than 750) or in cases of renal insufficiency, tophaceous deposits, nephrolithiasis, or on diuretics or low aspirin
Allopurinol adverse effects (3)
- rash
- leukopenia thrombocytopenia
- allopurinol hypersensitivity syndrome (severe cutaneous reaction stephen johnson syndrome with fever, hepatitis, eosinophilia, and acute renal failure)
HLA-B 5801 genotype
Subpopulation at higher risk for allopurinol hypersensitivity syndrome including koreans, chinese and thai - may indicate avoidance of allopurinol and use of febuxostat instead
Febuxostat (uloric) function and ADR’s (2)
Xanthine oxidase inhibitor with different chemistry than allopurinol that can be used for those that fail allopurinol or concern about side effects, sees similar reduction in gout flares and tophus area in treatment groups, ADR is liver function abnormalities and cardiotoxicity
Chronoic tophaceous gout
4th stage of gout, can enter chronic polyarticular phase which can be confused with other conditions, deposits can accumulate over time, often irregular asymmetric distribution with erosions with overhanging edges on x ray
Calcium pyrophosphate deposition disease (CPPD) definition
Depostis occuring producing calcification of articular cartilage, synovium menisci, and periarticular tissues, can be asymptomatic or presents with a variety of clinical syndromes, tends to present in older patients than younger
Common ways CPPD presents (5)
- asymptomatic chondrocalcinosis
- acute arthritis “pseudogout”
- pseudo-osteoarthritis
- pseudorheumatoid arthritis
- pseudoneuropathic arthropathy
CPPD Diagnosis (2)
- aspiration of joint demonstrating a rod shaped weakly positive birefrigence crystal
- characteristic intra-articular calcified deposits in synovium, articular cartilage, or menisci
CPPD crystals appearance on histological slide
Rhomboid shaped, smaller than WBC’s, weakly positive birefringence
CPPD management (4)
- NSAIDS
- Colchicine
- Intraarticular or oral steroids
- correct underlying metabolic condition
Cacium apatite crystals definition
Found in a wide variety of disorders, individual crystals cannot be seen in ordinary microscope, aggregates of clumped material can sometimes be found, but does not show any specific characteristics on polarizing miicroscopy, associated with bursitis, tendinitis, enthesopathies, destructive arthropathies, osteoarthritis
Associated conditions with calcium apatite crystals (3)
- renal failure long term dialysis
- connective tissue diseases (scleroderma)
- hypercalcemia
Calcium apatite crystal management (3)
- NSAIDS or local steroid injection
- parathyroidectomy in extreme cases
- joint replacement
