Crystal Arthropathy / Common Rheumatic Diseases Flashcards
Describe crystal deposition disease and some of the common ones?
Characterised by deposition of mineralised material within joints and peri-articular tissue.
COMMON:
- Monosodium urate – gout
- Calcium pyrophosphate dihydrate (CPPD) – Pseudogout
- Basic calcium phosphate hydroxy-apatite (BCP) – calcific periarthritis/tendonitis
What is hyperuricaemia?
Hyperuricaemia – excess of uric acid in the blood, usually majority produced daily (breakdown of purines from diet) is excreted by kidney and the rest by the biliary tract. In the vast majority of people with gout, hyperuricaemia results from reduced efficiency of renal urate clearance.
Why may hyperuricaemia occur?
Overproduction – malignancy, severe exfoliative psoriasis, drugs (E.g. ethanol, cytotoxic drugs), inborn error of metabolism, HGPRT deficiency. Under excretion – renal impairment, hypertension, hypothyroidism, drugs (e.g. alcohol, low dose aspirin, diuretics, cyclosporin), exercise, starvation, dehydration, lead poisoning.
What is Lesch Nyan syndrome?
HGPRT deficiency, X-linked recessive. Intellectual disability, aggressive and impulsive behaviour, self-mutilation, gout, renal disease.
What is gout?
Kind of arthritis caused by build-up of uric acid crystals in the joint, which causes sudden severe joint pain. Usually affects big toe. May be red, hot, swollen skin over affected joint.
How do you manage an acute attack of gout?
NSAIDS. Steroids (I/A, I/M, oral). Colchicine.
When would you treat hyperuricaemia?
1st attack is not treated unless: single attack of polyarticular gout, tophaceous gout (nodular masses), urate calculi (stones), renal insufficiency. Treat if 2nd attack within 1 year. Prophylactically prior to treating certain malignancies. DO NOT treat asymptomatic hyperuricaemia.
How would you treat hyperuricaemia/lower uric acid?
Xanthine oxidase inhibitor e.g. Allopurinol. Febuxostat. Uricosuric agents e.g. sulphinpyrazone, probenecid, benzbromarone. Canakinumab.
What are the rules for lowering uric acid levels?
Wait until acute attack has settled before attempting to reduce the urate level. Use prophylactic NSAIDS or low dose colchicine/steroids until the urate level is normal. Adjust allopurinol dose according to renal function.
Describe pseudogout and its management
The knee is to pseudogout as the toe is to gout. Effects elderly females, erratic flares. Aetiology – idiopathic, familial, metabolic. Triggers – trauma, undercurrent illness. Management – NSAIDS, I/A steroids; there are no prophylactic therapies.
What is Polymyalgia Rheumatica?
Inflammatory condition affecting elderly characterised by SUDDEN onset of shoulder +/- pelvic girdle STIFFNESS. Close relationship to giant cell arteritis (vasculitis). > 50, Usually >70y/o; F>M.
What are the signs of Polymyalgia Rheumatica?
ESR usually > 45 often 100. Anaemia. Malaise; Weight loss; Fever; Depression. Arthralgia (joint pain) / synovitis occasionally.
How do you manage polymyalgia Rheumatica?
Prednisolone 15mg per day initially. 18-24-month course. Bone prophylaxis. (Usually dramatic response to steroids).
