MSK and Skin and Rheum

Question 1

fell with wrists extended to break fall. point tenderness between EPL and EPB. what is dx?

Answer 1

avascular necrosis of scaphoid

Question 2

what is reponsible for keloid formation

Answer 2

TGF-B- anti-inflammatory that increases CT synthesis

Question 3

what causes urticaria?

Answer 3

dermal edema due to increased permeability of dermal microvasculature

Question 4

what does ATP do in the muscle stroke thingi?

Answer 4

it released myosin head from actin

Question 5

acute gouty arthritis, treatment and what does it do?

Answer 5

NSAID, prevents inflammation via neutrophils

Question 6

55 yo man w proximal weakness, biopsy shows endomysial mononuclear infiltrate and patchy muscle fiber necrosis, autoantibody against what?

Answer 6

tRNA synthetase (anti-Jo-1) and Anti-ANA.

Question 7

16 yo girl with left elbow pain, worse with exercise, steroid injection given at tendon, dx and what mvmt is affected?

Answer 7

tennis elbow, wrist extension by extensor carpi radialis and extensor digitorum

Question 8

sciatica entrapment in greater sciatic foramen, what muscle impinges?

Answer 8

piriformis

Question 9

small, multiple hypopigmented macules across skin, dx and appearance?

Answer 9

malassezia globosa (pityriasis versicolor) tinea versicolor. has spaghetti and meatball appearance due to spores and hyphae

Question 10

melanocytes are derived from neural crest or neuroectoderm?

Answer 10

neural crest

Question 11

eczema- atopic dermatitis, characterized by what on skin biopsy?

Answer 11

spongiosis- epidermal edema

Question 12

erythematous pruritic papules vesicles and bullae that are bilateral and symmetrical, malabsorption, dx?

Answer 12

dermatitis herpetifiormis. you see increased lymphocytes in intestinal epithelium

Question 13

tumor underneath nail, 2 options

Answer 13

glomus tumor (temperature regulation) and subungual melanoma

Question 14

arthralgia, fatigue in 43 yo woman, dry mouth, diffuse swelling of parotids and biopsy shows germinal center, dx and complication from this?

Answer 14

sjogrens syndrome, and non-hodgkin lymphoma due to chronic B-cell stimulation

Question 15

endomysium vs perifascicular

Answer 15

polymyositis vs dermatomyositis (closer to skin)

Question 16

what common drug increases calcium reabsorption and decreased risk of fracture?

Answer 16

thiazide diuretic, blocks NaCl, activates Na/Ca exchanger, creates gradient for absorption of Ca

Question 17

fever, pruritic skin rash and arthralgia after giving infliximab for crohn’s disease. dx and lab finding?

Answer 17

serum sickness, decreased C3, vasculitis due to immune complex formation. and neutrophil and fibrinoid necrosis in blood vessels.

Question 18

x linked mutation of phosphoribosyl pyrophosphate (PRPP)enzyme, which increases substrate conversion- what does this lead to?

Answer 18

gout. PRPP is needed for purine synthesis

Question 19

how to monitor disease progression in AS, and 3 extraskeletal manifestations of ankylosing spondylitis?

Answer 19

chest wall expansion; respiratory, aortitis, uveitis

Question 20

fracture at the fibular neck, what lesions?

Answer 20

lack of eversion, lack of dorsiflexion, lack of sensory over the dorsum