Mehl PED bullets general Nr 3 MSK Flashcards
10F + violaceous erythema of upper eyelids + scaly knuckles and finger joints; Dx?
dermatomyositis
asked on Peds NBME; heliotrope rash + mechanic’s hands; Gottron papules and shawl rash can also be seen; Dx with electromyography and anti-Jo1/-Mi2 (same as polymyositis); definitive Dx is muscle biopsy; Tx acute flares with steroids.
15M + 5’11” + plays soccer + knee pain; Dx?
Osgood-Schlatter
inflammation of patellar ligament at the tibial tuberosity; occurs in fast-growing, active teenagers; USMLE wants “repeated avulsion microfractures” as an answer.
Kid + recurrent knee redness, warmth, pain + fever?
Juvenile rheumatoid arthritis (JRA; called Still disease if there are extra-articular manifestations like fever and rash).
Kid + recurrent joint pain +/- high ESR +/- rash?
JRA
Kid + sore throat two days ago + high ESR + Hx of intermittent knee pain + presents today with knee pain + afebrile; Dx?
JRA -> infection can be a precipitating factor for a flare.
JRA Tx?
NSAIDs + corticosteroids.
7F + 1-yr Hx of occasional fever and knee pain + low Hb + MCV 75; Dx?
anemia of chronic disease
(AoCD) secondary to JRA -> low MCV seen AoCD in various Qs on 2CK NBMEs (resources classically
say normocytic [80-100]).
6M + suspected JRA + red, hot, painful knee. What need to do?
must do arthrocentesis to rule out septic arthritis. If
the vignette sounds like classic transient synovitis (affects hip, not knee), you do not need to do an
arthrocentesis.
6M + viral infection + now has hip pain +/- fever; Dx? Tx?
toxic synovitis (aka transient synovitis), not septic arthritis -> inflammation of the synovial lining of hip joint; Tx is supportive.
5F + 2-day Hx of limp and left hip pain + a week ago had watery stools and a temp of 100F + pain with weight-bearing and movement + no swelling or erythema; Tx?
answer = ibuprofen (toxic synovitis).
3F + recurrent joint pain + fever + rash; Q says “in addition to naproxen, which of the following is the next best step in Mx?
answer = slit-lamp exam
indicated annually (high risk of anterior uveitis).
14M + on knees helping dad with plumbing under kitchen sink for several hours + knee pain + joint shows no effusion + no fever; Dx?
prepatellar bursitis.
15F + severe pain of sternoclavicular joint + fever + arthrocentesis yields thick, yellow fluid + gram stain shows gram-negative diplococci; next best step?
culture of the aspirate fluid”; student says “wtf why? You’ve already determined the organism”
-> determine sensitivities; but empirically she would receive IM ceftriaxone and oral azithromycin or doxycycline; if septic, do IV therapy.
3M + fever + bone pain of the tibia + Tc99 bone scan shows uptake in diaphysis; Dx?
answer = Ewing sarcoma
presents like osteomyelitis with bone pain and fever; t(11;22); onion-skinning on histo; blue cells.
16M + soccer tournament yesterday + fever + high WBCs + bone pain + Tc99 bone scan shows uptake in the metaphysis; Dx?
osteomyelitis; uptake in metaphysis, not diaphysis (Ewing).
3F + 3-month Hx of leg pain predominantly in calves + occurs at night and wakes her from sleep + exacerbated by daily activity + relieved by acetaminophen + vitals normal + P/E normal; Dx?
answer on Ped NBME = growing pains (weird Dx you need to know).
Patient has “knock-knees” (i.e., knees touch); Dx?
genu valgum.
9F + both legs bowed + parents noticed bowing since she started to walk + recently bowing worse in right leg + x-ray while standing shows collapse of the medial aspect of the metaphysis of proximal tibia + rest of vignette describes healthy, thriving patient; Dx?
answer = tibia vara (Blount disease); wrong answer is rickets; should be noted that bowing is physiologic age < 2 years; tibia vara.
11F + spina bifida + paraplegic and wheelchair-bound + swelling and pain in thigh for two days + afebrile; next best step?
“x-ray of lower extremity”; fracture may indicate child abuse.
4-month-old + “clicking/clunking” on physical exam –> (+) Ortolani and Barlow maneuvers. Dx?
Primary hip dysplasia (congenital hip dysplasia) -> once these are positive, the next best step is ORTHO REFERRAL if it is listed.
referral always sounds wrong, but this is the correct answer if it’s listed; if it’s not listed, do ultrasound if under 6 months, or x-ray if over 6 months. Tx is with abduction harness (Pavlik harness; looks frog-leg-like).
Newborn girl + palpable clunk when the hip is abducted, flexed, and lifted forward; what is the most likely mechanism of the disease?
shallow, poorly developed acetabulum” (congenital hip dysplasia).
5-8-year-old boy with painful limp; no other risk factors; x-ray shows contracted capital epiphysis; Dx?
Legg-Calve-Perthes (idiopathic avascular necrosis); the word “contracted” wins over “capital epiphysis”
this is a Q on one of the NBME forms where everyone selects slipped capital femoral epiphysis (SCFE), but it’s Legg-Calve-Perthes;
Tx = hip replacement.
5-8-year-old boy with painful limp + sickle cell disease; Dx?
avascular necrosis (but not Legg-Calve- Perthes, because LCP is idiopathic).
11-13-year-old overweight boy with a painful limp?
Slipped capital femoral epiphysis (SCFE)
Tx = surgical pinning.
