Crystalline Arthropathies

Question 1

What are the four diseases associated with hyperuricemia?

Answer 1

Hypertension
Renal insufficiency
Obesity
Arteriosclerotic heart disease

Question 2

What is the etiology of hyperuricemia due to underexcretion of uric acid?

Answer 2

Reduced filtration of uric acid, enhanced tubular reabsorption or decreased tubular secretion

Question 3

What is the frequency of hyperuricemia due to underexcretion of uric acid?

Answer 3

90% of patient with gout has hyperuricemia due to underexcretion of uric acid

Question 4

What is the etiology of hyperuricemia due to overproduction of uric acid?

Answer 4

Hypoxanthineguanine phosphoribosyltransferase deficiency or 5-phosphoribosyl-1-pyrophosphate synthetase over activity. Both are X-linked inborn errors of murine metabolism

Question 5

What is the frequency of hyperuricemia due to overproduction of uric acid?

Answer 5

10%

Question 6

What is the error responsible for Lesch-Nyhan syndrome?

Answer 6

complete deficiency of hypoxanthine-guanine phosphoribosyltransferase

Question 7

What is the genetic inheritance for Lesch-Nyhan syndrome?

Answer 7

X-linked disorder

Question 8

What are the clinical findings for Lesch-Nyhan syndrome?

Answer 8

by hyperuricemia, self-mutilation, choreoathertosis, spasticity, growth retardation & severe gouty arthritis

Question 9

What is the genetic inheritance of xanthine oxidase deficiency?

Answer 9

AR

Question 10

What are the clinical findings of xanthine oxidase deficiency?

Answer 10

hypouricemia, xanthinuria with xanthine stones and myopathy associated with deposits of xanthine & hypoxanthine

Question 11

What is mechanism of hypouricemia seen in Fanconi syndrome?

Answer 11

Diminished reabsorption of uric acid causing hyporuricemia.

Question 12

What are the diseases associated with Fanconi syndrome?

Answer 12

Wilson disease, carcinoma of the lung, acute myelogenous leukemia, light-chain diseases, and use of outdated tetracycline

Question 13

What are the causes of hypouricemia associated with increased excretion of uric acid?

Answer 13

Fanconi syndrome
Malignant neoplasm (carcinoma)
Hodgkin disease
Sarcoma

Question 14

What are the causes of hypouricemia associated with the decreased synthesis of uric acid?

Answer 14

Taking allopurinol which inhibits the enzyme xanthine oxidase
Congenital deficiencies in enzymes involved in purine biosynthesis: 5-phosphoribosyl-1-pyrophosphate synthetase deficiency, adenosine deaminase deficiency, purine nucleoside phosphorylase deficiency and xanthine oxidase deficiency (xanthinuria).
Acquired deficiency in xanthine oxidase activity (metastatic adenocarcinoma of lung)
Acute intermittent porphyria

Question 15

What are the factors that can predispose a patient to an attack of gout or pseudogout?

Answer 15

Trauma
Operation (3 days after- cardiac transplant)
Major medical illness (MI, cerebrovascular accident, pulmonary embolus)
Fasting
Alcohol use
Infection
Acidosis

Question 16

What are the drugs that cause secondary hyperuricemia?

Answer 16

Thiazide diuretics
Furosemide
Ethacrynic acid
Ethambutol
Pyrazinamide
Low-dose aspirin
Cyclosporine
Nicotinic acid
Laxative abuse
Levodopa
Rasburicase

Question 17

What is the most commonly affected joint in gout?

Answer 17

50%= metatarsophalangeal joint of the great toe (Podagra)

Question 18

What is the clinical presentation of gout?

Answer 18

Rapid joint swelling with extreme tenderness and redness, Monarticular and most often involves the joints in the lower extremities. Mostly in middle aged men or women after menopause

Question 19

How do you Dx gout?

Answer 19

Uric acid crystals that are needle shaped and strongly negatively birefringent under polarized light. High amount of polymorphonuclear neutrophil in joint fluid

Question 20

What is the therapeutic option of choice for the treatment of acute gouty arthritis?

Answer 20

Indomethacin

NSAID

Question 21

What are the contraindications to NSAID or indomethacin use?

Answer 21

Contraindicated in patients with congestive heart failure, active peptic ulcer disease or renal insufficiency.
NSAID should not be used in patients with nasal polyps and aspirin sensitivity because they may cause bronchospasm.

Question 22

What are the therapeutic options for the treatment of acute gouty arthritis in patients with contraindications to colchicines and NSAIDs?

Answer 22

Intra-articular or oral corticosteroid and subcutaneous adrenocorticotropic hormone

Question 23

What is the toxicity associated with oral versus IV colchicines?

Answer 23

High dose oral colchicines can give severe GI side effect so it’s given in IV form

Question 24

What are the contraindications to colchicines?

Answer 24

Renal insufficiency, bone marrow depression, sepsis and immediate prior use of oral colchicine. Repeated dose should be avoided.

Question 25

What is the use of prophylactic colchicines to prevent exacerbation of acute gout?

Answer 25

Oral colchicine (0.6mg) is given twice day prophylactically with probenecid or allopurinol for 6-12months to prevent exacerbation of acute gout.

Question 26

What are the indications for the use of allopurinol rather than probenecid for lowering the uric acid level in gout?

Answer 26

Allopurinol is xanthine oxidase inhibitor and is the drug of choice to prevent gouty attack if the patient has a history of renal stones, tophi or renal insufficiency. It can also precipitate gout
It is used rather than probenecid for lowering the uric acid level are tophaceous gout, gout complicated by renal insufficiency, uric acid excretion more than 1,000mg/day, history of uric acid calculi, use of cytotoxic drugs and allergy to uricosuric agent

Question 27

What are the diseases associated with calcium pyrophosphate disease (CPPD)?

Answer 27

Acute inflammatory arthritis (pseudogout)

Question 28

What are the most commonly affected joints in pseudogout?

Answer 28

Mostly commonly affects the knees, but the wrists, elbows, ankles and intervertebral disks may be involved

Question 29

What are the findings on joint aspiration of pseudogout?

Answer 29

CPPD crystals are weakly positively birefringent and are rhomboid.

Question 30

What are the findings on radiography of pseudogout?

Answer 30

Most patients have chondrocalcinosis on radiography

Question 31

What are the therapeutic options of choice for the treatment of acute pseudogout?

Answer 31

NSAIDs
Injection of a steroid
IV colchicine is effective for acute attacks
Prophylactic oral colchicine can be given to decrease in the frequency and severity of attacks.

Question 32

What is the the clinical presentation of hydroxyapatite deposition disease?

Answer 32

Acute inflammation, including calcific tendinitis, osteoarthritis with inflammatory episodes, periarthritis or arthritis dialysis syndrome and calcinotic deposits in scleroderma

Chronic inflammation, including severe osteoarthritis and Milwaukee shoulder or knee: advanced glenohumeral and knee osteoarthritis, rotator cuff tear, noninflammatory, paste like joint fluid containing hydroxyapatite.

Question 33

What are the microscopic findings of hydroxyapatite deposition disease?

Answer 33

Individual crystals can’t be seen in polarization microscopy instead small, round bodies are seen. One needs electron microscopy to see needle shaped crystals.
Alizarin red stain shows calcium staining and this can also help diagnose the disease if CPPD is excluded.