Crystal arthropathy Flashcards
Define gout?
disorder of uric acid metabolism causing recurrent bouts of acute arthritis caused by deposition of monosodium urate ( MSU) crystals
what is pseudogout?
form of arthritis that results from the deposits of calcium pyrophosphate dehydrate crystals- commonly affectes knees and wrists
outline the aetiology of gout?
metabolic distubrance caused by hyperuricaemia
caused by increased urate intake or production
- increased dietary intake ( seafood, red meat, alcohol)
- increased nucleic acid turnover ( Lymphoma, leukaemia, psoriasis)
- increased synthesis of urate ( Lesch- Nyhan syndrome)
Decreased renal excretion
- idiopathic
- drugs ( Cyclosporin, alcohol, loop diuretics, aspirin, salicyclates)
- renal dysfunction)
what are the risk factors for gout?
Older age (peak in males: 40-60yrs; peak in females: 50-70yrs)
Male
Menopause(very rare in pre-menopausal women)
Thiazide and loop diuretics use
Pyrazinamide (used to treat TB) – increases urate reabsorption
Genetic susceptibility
Insulin dependence
Met syndrome
what are the rarer conditions that increase the risk of pseudogout?
o Haemochromatosis
o Hyperparathyroidism
O hypothyroidism
O acromegaly
o Hypomagnesaemia
o Hypophosphatasia
what are the precipitating factors of pseudogout?
Intercurrent illness
Surgery
Local trauma (especially of the meniscus of the knee)
outline the aetiology of pseudogout?
- CPPD crystal formation is initiated in cartilage located near the surface of chondrocytes
- linked with excessive calcium pyrophosphate production
- abundance of calcium pyrophoshpate leads to the formation of CPPD crystals
- Shedding of crystals in to the joint cavity leads to acute arthritis
- Most causes of joint damage predispose to pseudogout (e.g. osteoarthritis, trauma)
- More common in older individuals; seems to be more likely with a FH
summarise the epidemiology of gout?
- 10 x more common in MALES
- Very rare pre-puberty
- Rare in pre-menopausal women
- More common in HIGHER social classes
summarise the epidemiology of pseudogout?
- 2 x more common in WOMEN
- More common in the ELDERLY
what are the precipitating factors of an acute attack of gout?
- Trauma
- Infection
- Alcohol
- Starvation
- Introduction or withdrawal of hypouricaemic agents
what are the symptoms of an acute attack of gout?
- Sudden excruciating monoarticular pain- Usually affecting the metatarsophalangeal joint of the great toe (podagra)
- Symptoms peak at 24 hrs
- Resolve over 7-10 days
- Sometimes, acute attacks can present with cellulitis, polyarticular or periarticular involvement – joint stiffness and swelling (usually monoarticular or oligoarticular – v.few joints affected)
- Attacks are often recurrent
- Patients are symptom-free between attacks
what is intercritical gout?
asymptomatic period between acute attacks
what is chronic trophaceous gout
Follow repeated acute attacks
what are the symptoms of chronic trophaceous gout?
- Persistent low-grade fever
- Polyarticular pain with painful tophi(urate deposits) - Best seen on tendons and the pinna of the ear
- Symptoms of urate urolithiasis (renal calculi symptoms)
what are the presenting symptoms of pseudogout?
Acute Arthritis
- Painful
- Swollen Joint(e.g. knee, ankle, shoulder, elbow, wrist)
Chronic Arthropathy
- Pain
- Stiffness
- Functional impairment
Uncommon Presentations
- Tendonitis
- Tenosynovitis
- Bursitis
what are the signs of pseudogout on physical examination?
Acute Arthritis
- Red
- Hot
- Tender
- Restricted range of movement
- Fever (uncommon)
Chronic Arthropathy
- Similar to osteoarthritis
- Bony swelling
- Crepitus
- Deformity
- Restriction of movement
describe the plain radiograph of the joint in pseudogout?
chondrocalcinosis
compare gout and pseudogout?
