Joint disease

Question 1

Joint findings in Osteoarthritis

Answer 1

narrowed joint space, bone spurs, DIP and PIP involvement, subchondryl cysts, eburnation (polished, ivory-like appearance of bone). no MCP invovlement
(Heberden nodes on DIP and Bouchard nodes on PIP)

Question 2

Etiology of rheumatoid arthritis

Answer 2

inflammatory. mediated by cytokines and type III and IV hypersensitivity rxns

Question 3

Joint findings in RA

Answer 3

pannus formation in joints (abnormal granulation tissue d/t irritation of the synovium. granulation tissue will contract), subcutaneous rheumatoid noducles, ulnar deviation, baker cyst in popliteal fossa. no DIP involvment

Question 4

Antibodies in RA

Answer 4

80% of rheumatoid factor (IgM ab against IgG antibody (Fc portion)). anti-cyclic citrullinated peptide is more speicifc

Question 5

What the systemic symptoms of RA?

Answer 5

fever, fatigue, pleuritis, pericarditis. can cause anemia of chronic disease and secondary amyloidosis

Question 6

Tx for RA?

Answer 6

NSAIDs, glucocorticoids, and disease modifying agents ike methotrexate, sulfasalazine, and TNF-alpha inhibitors

Question 7

Causes of gout

Answer 7

hyperuricemia:

1. undersecretion of uric acid. usually idiopathic, but may be worse with thiazide diuretics
2. overproduction of uric acid (only 10%). Seen in incr. cell turnover from leukemia or myeloproliferative disorders, Lesch-Nyhan syndrome (X-linked dificiency of HGPRT; also have self-mutilation and intellectual disability), or renal insufficency, (or Von Gierke glycogen storage disease)

Question 8

What crystals are found in joints in gout? characteristics?

Answer 8

MSU (monosodium urate crystals) in tissues. needle shaped crystals w/ negative bifuringence under polarized light (yellow when parallel, blue when perpendicular)

Question 9

Classic manifestation of gout. complications of gout

Answer 9

painful MTP join of the big toe- podagra.

tophi, and renal failure

Question 10

What might precipitate a gout attack?

Answer 10

large meal, EtOH (alcohol metabolites compete for the same excretion sites in the kidney. decr. uric acid secretion and buildup in blood

Question 11

Treatment of gout

Answer 11

acute: NSAIDs (indomethicin), glucocorticoids, colchicine
chronic: xanthine oxidase inhibitors like allopurinol or febuxostat.

Question 12

pseudogout: findings, classic presentation

Answer 12

deposition of calcium pyrophosphate crystals. chondrocalcinosis on X ray. basophilic, rhomboid crystals. usually affects the large joints (like knee)

Question 13

predisposing conditions for pseudogout

Answer 13

hemochromatosis, hyperparathyroidism, hypoparathyroidism

tx: NSAIDs, steroids, colchicine

Question 14

Common causes of infectious arthritis

Answer 14

s aureus, streptococcus, and Neisseria gonorrhoea.

gonorrhea presents with synovitis, tenosynovitis (hand), and dermatitis (pustules)

Question 15

Features of seronegative spondyloarthropathies

Answer 15

no rheumatoid factor. associated with HLA-B27 and more common in males.

Question 16

biochem of gout

Answer 16

break down of purines (AMP and GMP) AMP to hypoxanthine, GMP to guanine. both go to xanthine, which is converted to uric acid by xanthine oxidase.
hypoxanthine and guanine may be salvaged by HGPRT. if no HGPRN (Leish nyhan syndrome), pt has excess uric acid