Gouty Arthritis/Gout is a type of crystal arthropathy characterized by recurrent attacks of acute arthritis.
Pathophysiology, clinical features, investigations, treatments modalities and complications
2. INTRODUCTION
1. It is type of crystal arthropathy.
2. A metabolic disease characterized by recurrent attack of acute inflammatory arthritis
caused by elevated levels of uric acid in the blood (hyperuricemia).
3. Most common rheumatic disease of adulthood
4. The uric acid crystallizes and deposits in joints, tendons, and surrounding tissues.
5. Hyperuricemia : overproduction/underexcretion/both
Hyperuricemia ≠ Gout
6. ASYMPTOMATIC HYPERURICEMIA
Serum [urate] abnormally high without Surgery
Male >420μmol/L (7mg/dL)
Female >360μmol/L (6mg/dL)
Not life threatening and readily treatable
Routine prophylactic treatment is NOT required
A/W : gout, urolithiasis, nephropathy, metabolic syndrome (HPT, DM/IFG/IGT,
hyperTGemia, obesity, CKD)
Serum [urate] >540μmol/L (9mg/dL) were a/w greater incidence for GOUT
Increased daily urinary urate excretion is a/w higher risk of URATE AND CA OXALATE STONE
FORMATION (when >0.65mmol/L or 11mg/dL)
RENAL INVOLVEMENT when serum urate level is more than 2x the normal limit (0.77mmol/L or
13mg/dL in male; 0.60mmol/L or 10mg/dL in female)
7. ACUTE GOUT
• Acute, self limiting, monoarticular
• Painful, red, hot, swollen
• Usually resolves within 2 weeks
if untreated
• May occur even if serum urate is
normal
• LL > UL
11. CHRONIC GOUT
• Polyarticular arthritis + tophi formation
• Articular tophaceous gout may results in
destructive arthropathy and secondary OA
• Tophaceous disease more like to occur in
patients with: Polyarticular presentation
• Serum urate level >540 μmol/L (>9mg/dL)
• Disease onset at younger age (≤40 years)
• Sites of tophi
• Digits of hands and feet (most common)
• Pinna of ear (classic, less common)
• Bursa around elbows and knees
• Achilles tendon
14. DIAGNOSTIC CRITERIA
Two of the following criteria are required for clinical diagnosis :
1. Clear h/o at least 2 attacks of painful joint swelling with complete resolution
within 2 weeks
2. Clear history or observation of podagra
3. Presence of tophus
4. Rapid response to colchicine within 48 hours of treatment initiation
Definitive diagnosis : presence of monosodium urate crystals seen in synovial fluid/tissues
16. INVESTIGATIONS
Specific investigations for confirmation
• Serum uric acid
• Joint aspiration and crystal identification
• Not widely available
To detect complications
• Renal imaging
• Skeletal x-rays
To detect medical conditions a/w gout or
hyperuricemia
• CBC – TLC AND ESR are raised
• Serum creatinine/urea
• Serum blood glucose
• Fasting lipid profile
• UFEME(urine routine and microscopy)
• 24h urinary urate excretion :
Useful if renal calculus proven to be urate
stone
Indicated if on uricosuric agent
Assess risk of stone
Help to indicate whether overproduction or
underexcretion of urate
Range : 2-4 mmol/24h or 0.34-0.67g/24h
19. SKELETAL X – RAYS
• Acute gouty arthritis : normal; soft tissue
swelling
• Chronic tophaceous gout :
• tophi
• erosive bone lesions (punched out lesions)
• joint space is preserved until late stage
• pathognomonic in foot and big toe
20.
21.
22. RENAL IMAGING
Plain abd XR detects only 10% of all
urate stones
IVU = investigation of choice for urate
stones
US KUB : investigations of choise for
nephrocalcinosis, significant renal
stones (>3mm) whether radio-opaque
or radiolucent, obstructive
nephropathy
Plain CTU : most sensitive to detect any
stone
23. MANAGEMENT
Lifestyle modification and dietary advice
Management of comorbidities
Nonessential prescriptions that induce
hyperuricaemia
Main aim :
To achive ideal BW
Prevent acute gouty attacks
Reduce serum urate level
Strict purine-free diet reduced only 15 –
20% of serum urate, thus is considered an
adjunct therapy to medication.
Adding vitamin C supplements to patients’ daily
diet has been conditionally recommended against,
regardless of disease activity.
24. ASYMPTOMATIC HYPERURICEMIA
Pharmacotherapy of asymptomatic hyperuricemia is NOT necessary, except :-
Persistent severe hyperuricemia
> 770μmol/L (13mg/dL) in male
> 600μmol/L (10mg/dL) in female
Persistent elevated urinary excretion of urate
> 0.65mmol/L/day (11mg/day), a/w 50% increased risk of urate calculi
Tumor lysis syndrome
chemotherapy/radiotherapy extensive tumor cytolysis
=> require pre-hydration and allopurinol to prevent acute urate nephropathy
25. ACUTE GOUTY ARTHRITIS
NSAIDs
eg. Ibuprofen, naproxen, Diclofenac,
indomethacin, mefenemic acid etc
Caution in h/o PUD, HPT, renal impairment,
IHD, liver impairment
COX-2 inhibitors (celecoxib, etoricoxib,
parecoxib) = alternative for above risk
factors
Studies have shown that etoxicoxib
(Arcoxia) has equal efficacy to
indomethacin
Colchicine
Inhibiting mitosis and neutrophils motility and activity,
leading to a net anti-inflammatory effect.
Alternative drug if CI to NSAIDs, but is poorly tolerated by
elderly – Diarrhoea
Therapeutic index is narrow
Slower onset of action
Evidence base for prophylaxis is stronger than for NSAIDs
(NHS Fife, Gout Management Guidelines, 2010)
SE (eg. N&V, abd. pain, profuse diarrhea) limit its usefulness
Dosage : 0.5mg – 0.6mg BD-QID
Initiation within 24 hours of onset
If on Allopurinol, continue without interruption
26. CHRONIC GOUT
Indications for Urate Lowering Therapy (ULT) (2020 ACR guidelines)
• Any1 of the following signs, including subcutaneous tophi (≥1), evidence of radiographic
damage by any modality that appears to be due to gout, and frequent gout flare occurrence
(>2 times/y).
•Recommendations for initiation of ULT were noted to be conditional for patients with a
previous history of infrequent gout flares (<2 flares/y).
•The subcommittee has conditionally recommended against the initiation of ULT for patients
who experience their first gout flare.
•In cases involving urolithiasis, stage ≥3 chronic kidney disease (CKD), and/or serum urate (SU)
concentration >9 mg/dL, ULT can be conditionally recommended.
•The subcommittee has conditionally recommended against initiating pharmacologic ULT in
patients with asymptomatic hyperuricemia (SU, >6.8 mg/dL and no previous gout flares or
subcutaneous tophi), including those with comorbid CKD, cardiovascular disease, urolithiasis, or
hypertension.
27. CHOICE OF ULT
•Allopurinol is the preferred first-line agent for the treatment of all patients with gout, including those with
moderate to severe CKD.
•Xanthine oxidase inhibitors (XOI) allopurinol or febuxostat have been strongly recommended over
probenecid for patients with moderate to severe CKD, with pegloticase recommended against as a first-
line therapy.
•Allopurinol may be strongly considered at starting doses of ≤100 mg per day, and at lower doses for
patients with stage ≥3 CKD.
•For febuxostat, starting doses of ≤40 mg per day with dose escalation to reach optimal dosing has been
strongly recommended as the second choice to allopurinol.
28. •When used as an initial therapy for gout, probenecid has been conditionally recommended at doses of
500 mg 1 to 2 times daily, with titration to higher therapeutic doses.
•The guidelines subcommittee has strongly recommended concomitant prophylaxis anti-inflammatory
therapy with colchicine, nonsteroidal anti-inflammatory drugs, or glucocorticoids, such as prednisone or
prednisolone, over no prophylactic treatment.
•Continuing anti-inflammatory prophylaxis has been recommended for 3 to 6 months over <3 months,
with regular evaluation as long as gout flares persist.
Timing of ULT Initiation
o Once ULT has been indicated for gout, clinicians may initiate treatment at the time of a flare rather
than starting treatment after the flare has been resolved.
o The subcommittee has strongly recommended a treat-to-target strategy with titration to reach target
SU over a fixed-dose approach for patients with gout receiving ULT.
o Achieving a stable SU target of <6 mg/dL vs no target for patients receiving ULT has been strongly
recommended.