Crystal Arthritis (Gout and CPPD) PDF

# Crystal Associated Arthritis - Gout and CPPD ## Gout - Gout occurs more commonly in males > females. - **Hint**: - Old age male ⇒ Gout - Young age male ⇒ Ankylosing Spondylitis ### Causes of gout 1. **Overproduction** - **Acquired**: - Diet - Disease (hematological...

# Crystal Associated Arthritis - Gout and CPPD ## Gout - Gout occurs more commonly in males > females. - **Hint**: - Old age male ⇒ Gout - Young age male ⇒ Ankylosing Spondylitis ### Causes of gout 1. **Overproduction** - **Acquired**: - Diet - Disease (hematological + psoriases + chemotherapy) - **Inherited** 2. **Underexcretion** - **Renal (90%)** 3. **Combination** - Also Alcohol ↑ uric acid + uric acid retention; so it is counted as combination. ## Stages of Gout 1. **Asymptomatic Hyperuricemia**: No need for treatment 2. **Acute Gout** 3. **Intercritical Period**: Asymptomatic period between attacks 4. **Chronic Tophaceous Gout**: Deformities and bone erosions - Punched out with overhanging edges. ### Acute Gout - **Presentation**: Acute monoarthritis (commonly in first MTP joint of big toe) - **DDX**: Septic arthritis - To differentiate, we do synovial fluid aspiration by polarized microscope. - **Findings**: Needle-shaped, negative birefringent crystals. ### Treatment of acute gout - NSAIDs/ if no contraindications - Colchicine/ Contraindicated in renal impairment and patients on statins. - **Avoid in DM** - Steroid - Local steroid injection - Anakinra (IL-1 agonist) ## Treatment of chronic gout - **Life style modification (diet)** - **Urate lowering drugs (there's 5 indications for it)** - **Education** - **Correction of predisposing factors**: - Stop Alcohol - Weight loss - **Avoiding hyperuricemic drugs**: - Thiazide diuretics - Loop diuretics (furosemide) - Niacin (B3) - Low doses of aspirin ### Foods to be avoided - All meats - Seafood - Meat extracts - Yeast extracts - Beans - Lentils - Peas - Oat - Spinach - Asparagus - Cauliflower - Mushrooms ### Indications of urate lowering treatment (ULT) 1. Frequent flares (more than 2-3 flares over 1 year) 2. Renal stone 3. Tophaceous gout: detected radiographically 4. Moderate to severe CKD 5. Evidence of bone or joint damage - **At the first few months, the risk of flares can be reduced by oral prophylaxis like NSAIDs.** ### Urate lowering drugs 1. **Xanthine oxidase inhibitors**: - Allopurinol (available and cheap) - Febuxostat (no need dose reduction) - Side effects of Allopurinol ⇒ hypersensitivity reaction - Needs dose reduction due to RFT 2. **Uricosuric drugs** - Contraindicated in renal stone and overproducers and renal impairment. 3. **Uricase (IV)** - Pegloticase: expensive and used in refractory cases. ## CPPD ### Causes 1. Idiopathic, closely related to OA 2. Genetic mutation (early onset CPPD) 3. Secondary to: - Primary hyperparathyroidism - Hypothyroidism - Hypomagnesemia - Hypophosphatemia - Hemochromatosis - Wilson's disease ### Presentation 1. Asymptomatic 2. Acute pseudogout - Most common 3. Chronic pseudo RA (knee + wrist) monoarticular (89%) 4. Chronic pseudo OA ### Diagnosis - Synovial fluid aspiration under polarized microscope - Findings: Rhomboid shape with positive birefringence. - X-ray shows chondrocalcinosis - Common sites for chondrocalcinosis: - Knee menisci - Wrist triangular ### Treatment - Same treatment of acute gout, + treat underlying cause - NSAIDs (if no contraindication) - Colchicine (not given in renal impairment and statin use) - Steroid (avoid in DM) - Local steroid injection - Anakinra (IL-1 agonist) - **The problem in pseudogout is calcium, not uric acid.**