Rheumatology- Paulson (exam 2) Flashcards
Gout S/Sx: (Pts may have:)
- Hyperuricemia
- Recurring attacks of acute arthritis
- Tophi
- Renal disease
- Uric acid nephrolithiasis
- Chronic deforming arthritis
What are tophi?
deposits of monosodium urate monohydrate crystals)
Gout: Epidemiology/RF?
- Men > Women (90% are men). Men: 40-60. Women: after 60.
- Pacific Islanders (Filipinos, Samoans)
- ALCOHOL (especially beer)
- OBESITY
- Genetic in some
- Foods that promote hyperuricemia
- Chronic diseases
- Medications
Gout: What foods may promote hyperuricemia?
- Red meat
- Seafood
- Fructose
Gout: What food is protective for hyperuricemia?
Dairy products
Gout: Which medications affect urate balance?
- Thiazides
- Loop diuretics
- Low-dose ASA
- Cyclosporine
- Niacin
Gout pathophysiology: Serum urate levels for hyperuricemia?
> 6.8 mg/dL
(T/F) For gout to result from hyperuricemia, serum urate levels are typically above 6.8 mg/dL prior to the onset of gout S/Sx.
- False. Especially rapid fluctuations in serum levels can precipitate S/Sx.
T/F: To dx a Pt with gout, they must have hyperuricemia
False. Hyperuricemia needed (but hyperuricemia ≠ gout)
For gout, _______ level has to be high enough for crystals to precipitate
monosodium urate (MSU)
Gout: How does resolution of acute inflammation occur?
- Mediated by immune mechanisms (even without treatment)
Gout: long term Complications?
- Chronic inflammatory process which has an effect on osteoclasts, blasts, and chondrocytes that contribute to tophi formation, erosion of bone, and joint injury.
Uric acid is the end product of ______ metabolism
purine
When considering uric acid balance, what are the two major categories?
- Underexcreters
- Overproducers
Uric acid balance: Which group is more common, underexcreters or overproducers?
- Underexcreters
Conditions associated with being an underexcreter?
- Renal insufficiency
- Acidosis (ie: diabetic ketoacidosis, ketogenic diet, lactic acidosis)
- Volume depletion/dehydration
- Lead exposure
- Medications
Uric acid balance: Which medications can make one under-excrete uric acid?
- **Low-dose ASA
- ** Thiazides
- **Loop diuretics
- Nicotinic acid
- Cyclosporine
- Levodopa
- Ethambutol
- Pyrazinamide
Uric acid balance: What conditions can make one overproduce uric acid?
- Inherited defect of metabolism
- Myeloproliferative and lymphoproliferative disorders, polycythemia, carcinoma–> Tumor lysis syndrome
- Chronic hemolytic anemias
- Transient hyperuricemia associated with ATP consumption.
Uric acid balance: What inherited defect of metabolism can lead to an overproduction of uric acid?
- Lesch-Nyhan syndrome
- Kelley-Seegmiller syndrome
Uric acid balance: What are examples of transient hyperuricemia associated with ATP consumption?
- Strenuous exercise
- Status epilepticus
- MI
- Sepsis
Gout: What are the 3 stages of gout?
1) Acute gouty arthritis
2) Intercritical (Interval) gout
3) Chronic articular and tophaceous gout.
Acute Gouty Arthritis- Chief complaint/Hx
- “My big toe hurts”
- Sudden onset, often at night
- Severely painful and tender, swollen joint, red, warm
- May complain of fever
- Reaches maximal severity in about 12-24 hours
- May have history of similar attacks prior
Acute gouty arthritis: PE findings?
- Swollen, very tender, red and warm overlying skin.
- (+/-) desquamation
- (+/-) Tophi
- (+/-) Podagra
Acute gouty arthritis: MC site?
- MTP of great toe is classic
- “Podagra”
- *Usually monoarticular and in the lower extremity
- *Polyarticular is possible (usually later flares)
What physical exam finding is pathognomonic for gout?
tophi (Irregular, asymmetric macroscopic deposits of urate)
Common sites for tophi?
- External ear
- Hands
- Olecranon
- Feet
- Knee
- Achilles tendon
- Forearm
Gout: Are tophi painful?
- Usually painless (but can become acutely inflamed)
- - Usually develop after years.
Gout: How can tophi be destructive over the sites they are found?
- Maintains a state of inflammation
- Promote tissue and joint destruction around them.
Renal complications of gout?
- **Uric acid nephrolithiasis
- **Chronic urate nephropathy
- Uric acid nephropathy
How can gout cause chronic urate nephropathy?
MSU crystals are deposited in the renal medulla and pyramids
Describe nephropathy
Nephropathy is a disease of the kidneys caused by damage to the small blood vessels or to the units in the kidneys that clean the blood.
How does gout cause uric acid nephropathy?
- Acute renal failure (ARF) when large amounts of uric acid and crystals precipitate in the collecting ducts and ureters.
- Usually seen as part of tumor lysis syndrome
DDx of acute gout?
- Septic arthritis
- Trauma
- Calcium pyrophosphate crystal deposition (CPPD) disease (pseudogout)
- Cellulitis
- Rheumatoid arthritis
- Lyme disease
DDx of chronic gout?
- Osteoarthritis
- Rheumatoid arthritis
- Psoriatic arthritis
Gout: Labs & Imaging for Dx?
- Synovial fluid analysis
- U/S
- Radiographs
What would you find in an aspirate of synovial fluid (analysis)? KNOW
- Monosodium urate crystals
- “Negatively birefringent”, needle-like, when viewed with polarized light microscopy. KNOW!!
Gout labs: U/S findings?
- Hyperechoic linear density (double contour sign) over the joint cartilage or deposits that look like tophi (hypoechoic cloudy area)`
Gout labs: Radiograph findings?
- “Rat bite” lesions later in disease process
- If next to a tophus = gout.
Gout labs: Additional labs?
- Serum uric acid (often elevated in most Pts during an attack)
- Peripheral WBC (can be high)
- ESR/CRP (can be elevated)
Gout Tx: If PT is asymptomatic but has hyperuricemia?
Don’t treat
Gout Tx: Lifestyle modifications?
- Lose weight
- Reduce alcohol consumption
- Reduce purine-rich food consumption
- Drink enough fluids to urinate >-2L per day
- Avoid hyperuricemic meds, if possible.
Gout Tx: Tx goal?
- Relieve the patient’s pain as quickly as possible.
- Keep in mind comorbidities when selecting meds
Gout Tx: (T/F) urate-lowering medications are the medications that can help the patient’s pain management in acute attacks.
False! they don’t help in acute attacks- don’t start one during acute attack
Gout Tx: What is an example of a common urate-lowering medication?
Allopurinol
Gout Tx: If a patient is on a urate-lowering medication and a gout flare-up occurs, should they discontinue that medication for the duration of the flare-up?
- No
- Continue as prescribed.
Gout Tx: What is the 1st line medication for an acute attack?
- NSAIDs
Gout Tx: Examples of common NSAIDs for an acute attack?
- Naproxen
- Indomethacin
- Celecoxib (Celebrex)
Gout Tx: How do you direct a patient to take an NSAID?
- Discontinue 1-2 days after complete clinical resolution.
- (Typical course might be 5-7 days)
Gout Tx: Contraindications to NSAID usage for acute attacks?
- CKD with CrCl < 60
- Active ulcer
- NSAID allergy
- Concurrent use of anticoagulant
- CV disease (esp. uncontrolled CHF or HTN)
Gout Tx: What is one of the best antigout medications used in acute attacks in patients who cannot take NSAIDs?
Colchicine
Gout Tx: When should a patient start taking colchicine?
Within 12-24 hours of symptoms
Gout Tx: Colchicine administration instructions? Doseage?
- DAY 1: 1.2 mg initially, then 0.6 mg 1 hour later.
- DAY 2 (& onward) 0.6 mg QD-BID
- d/c 2-3 days after symptoms have resolved.
Gout Tx: Common S/E of colchicine?
- Diarrhea
- Abdominal cramping
- Reversible peripheral neuropathy may be seen
Gout Tx: Contraindications to colchicine?
- Severe hepatic impairment
- Severe renal impairment
- Concomitant use of a mod-strong inhibitor of P-gp and/or CYP3A4 inhibitor
Gout Tx: When are corticosteroids a good option?
- Good for people who can’t take NSAIDs or colchicine
Gout Tx: How could you administer the corticosteroid during an acute attack? (routes and medication name)
- Intra-articular injection: triamcinolone 40 mg (large joint), 30 mg for a medium joint, or 10 mg for a small joint
- Oral: prednisone 40-60 mg/day tapered over 7 days
- IV: methylprednisolone 40 mg/day tapered over 7 days
- IM: triamcinolone 40-60 mg. May need to repeat 1-2x.
Gout Tx: Conditions that may be problematic with a corticosteroid plan?
- CHF
- Glucose intolerance (**dont use in diabetic pts)
- Poor control of HTN
Preventative Gout Tx: At what stage of gout would you address preventative measures?
During the intercritical period
Preventative Gout Tx: Goal?
- To achieve a serum urate level <6 mg/dL
- Slowly (not more than 1-2 mg/dL/month)
Preventative Gout Tx: Indications for urate-lowering medications?
- Frequent gout attacks
- Tophi
- Clinical or radiographic signs of chronic gouty arthropathy
- Gout with renal insufficiency
- Recurrent uric acid nephrolithiasis
- Premenopausal women or men <25 with urinary uric acid excretion >1100 mg/day
Preventative Gout Tx: When initiating antihyperuricemic therapy, what else do you have to consider?
- Use low-dose prophylactic colchicine (or low-dose NSAID) when initiating antihyperuricemic therapy to reduce risk for acute flare.
Preventative Gout Tx: Why should you use low-dose prophylactic colchicine (or low-dose NSAID) when initiating antihyperuricemic therapy?
To reduce risk for acute flare.
Preventative Gout Tx: What is the class of medication most commonly used to prevent gout flare-ups?
Xanthine oxidase inhibitors (XOI)
Preventative Gout Tx: What are the two main XOI medications used?
- Allopurinol
- Febuxostat
XOI: Action of these medications?
- Reduce production of uric acid.
XOI: Dosage and instructions for initiating allopurinol?
- Start at 100mg/day
- Titrate up every 2-5 weeks
XOI: Most people who take allopurinol require what dosage a day?
≥300 mg/day
XOI: When would you reduce the recommended initial dose of allopurinol in a patient?
In PTs with CKD
XOI: When initiating allopurinol, what other medication should you also initiate?
- Prophylactic colchicine (OR)
- Low-dose NSAID
XOI: S/E of allopurinol?
rash, including severe cutaneous reactions/TEN (especially in Asian patients, those with HLA-B*5801 allele)
-(Toxic epidermal necrolysis (TEN) is a rare, life-threatening skin reaction, usually caused by a medication. It’s a severe form of Stevens-Johnson syndrome (SJS).)
XOI: Febuxostate initial dosage?
- Start at 40mg/day and titrate up to 80mg after 2 weeks.
XOI: When initiating Febuxostat, what other medication do you want to initiate?
- Prophylactic colchicine (OR)
- Low-dose NSAID
XOI: S/E of febuxostat?
- Less hypersensitivity reactions
- Can develop abnormal LFTs, and slightly higher rate of cardiovascular events
Gout Tx: Describe uricosuric medications.
- Block tubular reabsorption of urate and increases the rate that uric acid is renally excreted.
Gout Tx: When considering initiating a uricosuric medication, what baseline lab would you consider having?
- The PT must have normal renal function (CrCl > 60)
Gout Tx: When a patient initiates uricosuric medications, what do you need to advise the patient of?
- Urinate at least 2L/day to avoid precipitation of uric acid in urinary tract.
Gout Tx: Common uricosuric medication? and S/E?
*Probenecid S/E: - Rash - Precipitation of acute gout - GI intolerance - Uric acid stone formation
Gout Tx: Uricosuric medications are contraindicated in which patients?
- renal hypofunction (CrCl<60)
- **PTs with G6PD
Gout Tx: When would you consider treating a patient with uricase?
- For patients who have been refractory to all other therapies.
Gout Tx: Describe uricase.
An enzyme present in other mammals that breaks urate down to allantoin, which is more easily excreted.
Gout Tx: Common uricase medication?
- Pegloticase: given IV every 2 weeks
Gout Tx: What special considerations need to be made before starting a uricase therapy?
- Need to have premedication for infusion reactions and have gout flare prophylaxis for the first 6 months of therapy.
Gout Tx: Uricase is contraindicated in which patients?
- PTs with G6PD deficiency.
Gout Tx: How do you choose your treatment?
- 24-hour urine uric acid test.
- Determine if the patient is an undersecreter of uric acid or an overproducer of uric acid.
Gout Tx: When looking at the results of a 24-hour urine uric acid test, what is the lab value point that separates undersecreters from overproducers?
<800 mg/dL–> they are an undersecreter of uric acid
> 800 mg/d–> they are an overproducer
In both cases give them an XOI
-if they fail XOI–> give uricase
Give allopurinol!! best choice
Gout Tx: Interpret a 24-hour urine uric acid test of 922 mg/dL
- Overproducer
Gout Tx: Interpret a 24-hour urine uric acid test of 700 mg/dL
- Undersecreter
Prognosis/Referral:
-what should you educate the Pt on regarding acute gouty attacks?
- Acute attack will self-resolve even without treatment
- Over time, attacks will become more frequent and last longer
- The younger a patient is at initial presentation, the more likely to have a progressive course
- With urate-lowering meds, much less chronic gouty arthritis, tophi, and deformity
- -Can refer to rheumatology
- Follow up
Describe Pseudogout
-Also known as calcium pyrophosphate dihydrate (CPPD or CPP) deposition disease, chondrocalcinosis, or pyrophosphate arthropathy
=Arthropathy caused by precipitation of calcium pyrophosphate dihydrate crystals that can cause acute, recurrent, or chronic arthritis which can mimic gout.
Chondrocalcinosis=
Radiographic evidence of calcification in articular cartilage
Risk factors for Pseudogout
- Older adults, both men and women
- Increases in prevalence with increasing age
- Rare before 55.
- Around 50% of those >85 are affected
- Joint trauma
- Familial chondrocalcinosis
- Hemochromatosis
Most CPPD (aka pseudogout) is _____
idiopathic
–but Early-onset familial CPPD with chromosomal linkages
Describe the pathophysiology of CPPD
- Excess pyrophosphate production in cartilage–> calcium pyrophosphate supersaturation–> CPP crystals are formed/deposited
- The CPP crystal is felt to be involved in joint inflammation
- Inflammation triggered by CPPD degrades cartilage
Clinical Sx of CPPD (2 types)
- asymptomatic
- Acute arthritis/pseudogout
Asymptomatic CPPD Pt lab findings
May see CPP deposition in a joint on a radiograph but have no symptoms
Acute Arthritis/pseudogout Sx
- Self-limited, sudden attacks of pain, redness, warmth, disability, and swelling, monoarticular or oligoarticular
- *Knee is most commonly affected.
- Others: wrists, shoulders, elbows, ankles
- Can be provoked by surgery (esp. parathyroidectomy), trauma, or major illness
- May have associated fever/chills
Chronic CPP crystal inflammatory arthritis (“pseudo-RA”) - describe this disorder
-Inflammatory arthritis where CPP crystals can be found in joint fluid
-Similar Sx to RA, involving multiple joints in a symmetric patterns
-Usually affects joints unaffected by OA
MCPs, wrists, elbows, glenohumeral joints
-Asynchronous waxing and waning of inflamed joints
OA with CPPD (“pseudo-OA”)
Describe this disorder
About half of symptomatic patients have progressive joint degeneration
- -Knees most common. Also wrists, MCPs, hips, shoulders, elbows, spine
- -Clinical exam like that of OA (tenderness, bony enlargement, crepitus, restriction of motion)
Pseudo-neuropathic joint disease
=Severe joint degeneration from CPP crystal deposition
- Resembles neuropathic arthropathy
- Unlike neuropathic arthropathy, there is not usually any neurologic impairment
DDx for Acute arthritis/pseudogout
Gout
Septic arthritis
Trauma
Lyme disease
DDx for Chronic CPP
Osteoarthritis
Rheumatoid Arthritis
Peripheral spondyloarthritis
Neuropathic arthropathy
Dx: Lab findings for CPPD
- *CPP crystals in joint aspirate are diagnostic
- **“weakly positively birefringent rhomboid crystals” by polarized light microscopy
- Radiographic evidence of chondrocalcinosis:
- -Linear and punctate densities within hyaline or articular cartilage
- -Often see degenerative changes (subchondral cysts, osteophyte formation, fragmentation of bone and cartilage)
Tx Acute pseudogout
- Aspiration then intraarticular glucocorticoid injection–>Triamcinolone
- NSAIDs: Indomethacin, naproxen, salicylates
- Colchicine
- Systemic corticosteroids (oral, IV, or IM)
Tx OA with CPPD
Treat like OA
Tx Pseudo-neuropathic joint disease
treat like charcot arthropathy
When should you consider Prophylaxis tx for CPPD?
Consider if the patient has ≥3 attacks per year
–>Colchicine 0.6 mg PO BID
If this doesn’t work or the patient is intolerant, could use an NSAID instead.
Pseudo-RA prophylaxis:
NSAIDs 1st choice (use lowest dose possible): Naproxen, or Indomethacin
- -Alternatives if NSAIDs ineffective:
- Colchicine 0.6 mg QD or BID
- Hydroxychloroquine
- Low-dose glucocorticoids ie: prednisone (up to 10 mg /day)
Prognosis/Referral: CPPD
Attacks will resolve even without treatment
Can cause chronic symptoms
Can refer to rheumatology
Compare & contrast Gout and CPPD Arthropathy
Gout: middle aged men and elderly men. Joints: MTP, ankles, knees. Dx: Tophi present. Crystals: needle-shaped and strongly negative birefringent
CPPD arthopathy: elderly men and women. Joints: knees MC!! and wrists. NO tophi present. Radiography: Chondrocalcinosis. Crystals: small, rhomboid shaped or weakly positive birefringent