Crystal Arthropothy Flashcards
What is crystal arthropathy?
Deposition of mineralised material within joints and peri-articular tissue
What type of crystals are found in gout?
Monosodium urate
What type of crystals are found in pseudogout?
Calcium pyrophosphate dyhydrate
What type of crystals are found in calcific periarthritis/tendonitis?
Basic calcium phosphate (hydroxy-apatite)
What is a tophus?
A deposit of crystaline uric acid
What causes tophi?
Massive accumulations of uric acid
Where does the majority of urate come from in the body?
Purine degradation
What is the most common cause of gout?
Reduced efficency of renal urate clearance
What can cause overproduction of urate?
Malignancy Lymphoproliferative, tumour lysis syndrome Severe exfoliative psoriasis Drugs - ethanol, cytotoxic drugs Inborn errors of metabolism HGPRT deficiency
What can cause under excretion of urate?
Renal impairment Hypertension Hypothyroidism Drugs - alcohol, low dose aspirin, diuretics, cyclosporin Exercise, dehydration, starvation Lead poisoning
What is Lesch Nyan syndrome?
Deficiency of Hypoxanthine-Guanine Phosphoribosyl transferase (HGPBT) - X-linked recessive
What are clinical features of Lesch Nyan syndrome?
Intellectual disability Aggressive and impulsive behaviour Self mutilation Gout Renal disease
What is the most common demographic of gout?
Older men
Why is gout less common in women?
Oestrogen leads to lower urate levels
How is acute flare up of gout managed?
NSAIDS
Colchicine
Steroids
How is uric acid lowered?
Xanthine oxidase inhibitor - allopurinol
Febuxostat
Uricosuric agents - sulphinpyrazone
Canakinumab
What are rules for lowering uric acid?
Wait until acute attack has settled before attempting to reduce urate level
Use prophylactic NSAIDs or low dose cochicine until urate level normal
Adjust allopurinol dose according to renal function
What cardiovascular and lifestyle factors need to be addressed in gout?
Hypertension Smoking High sugar diet Alcohol High fat diet Obesity
What population is most affected by pseudogout?
Elderly women
What are the 3 main aetiologies for pseudogout?
Idiopathic
Familial
Metabolic
What are triggers for flareups of pseudogout?
Trauma
Intercurrent illness
How is pseudogout managed?
NSAIDs
Intraarticular steroids
No prophylactic therapies
What is polymyalgia rheumatica?
Sudden onset of shoulder +/- pelvic girdle stiffness
What are clinical features of polymyalgia rheumatica?
Anaemia, malaise, weight loss, fever, depression, arthralgia, synovitis
How is polymyalgia rheumatica diagnosed?
Compatible history Age>50 ESR>50 Dramatic steroid response There is no specific diagnostic test
What are differential diagnoses for polymyalgia rheumatica?
Myalgic onset inflammatory joint disease Underlying malignancy Inflammatory muscle disease Hypo/hyperthyroidism Bilateral shoulder capsulitis Fibromyalgia
How is polymyalgia rheumatica treated?
Prednisolone 15mg per day
18-24 month course
Bone prophylaxis
