Mehl PED bullet in general nr 2 Flashcards
(34 cards)
3F + brown blood; Dx?
Congenital methemoglobinemia due to deficiency of cytochrome reductase B5.
10M + ate new batch of sausage from his father, who is a butcher + high methemoglobin level; Tx?
answer = “administration of methylene blue”; can also add vitamin C to regimen.
9-month-old boy + “can only sit with support” + “bangs two blocks together but does not scribble” + “says ‘mama’ and ‘dada’ but not specifically to his parent”; Q wants “normal” or “delayed” for Gross motor, Fine motor, and Language development; answer?
Delayed Gross motor + Normal fine motor and language development.
2-month-old boy + bilious vomiting + chronic constipation; Dx?
Hirschsprung; also associated with Down syndrome;
Diagn = “rectal manometry”
notable that this can cause bilious vomiting.
1-month-old boy + bilious vomiting + normal rectal tone + fecal occult blood positive; Dx?
midgut volvulus (Peds NBME form 2); intussusception and Hirschsprung are wrong answers.
18-month-old girl + intermittent abdominal pain for 24 hours + fecal occult blood test is negative + AXR shows dilated loops of small bowel and air-fluid levels; Dx?à
“volvulus”
in other words, if vignette sounds like intussusception but AXR shows dilated loops of small bowel and air-fluid levels, answer = midgut volvulus, not intussusception, and FOB isn’t specific for either.
Neonate + large vascular lesion on the leg + thrombocytopenia; Dx?
Kasabach-Merritt syndrome (aka hemangioma with thrombocytopenia) -> this is on the pediatric 2CK forms three times asked in different ways; students always say wtf and I have to explain that, yes, it’s weird, but it’s HY for some magical reason; this is not a strawberry hemangioma and requires surgical Tx.
1-month-old male + 12x8cm vascular lesion on buttocks since birth + examination shows scattered petechiae and bruises; what best explains these findings?
“platelet sequestration.” I’ve memorized this from the NBMEs -> similar to splenomegaly, which can cause thrombocytopenia from sequestration within the red pulp, the implication that the large vascular lesion of KMS is that platelets simply get caught within it.
Neonatal male with PUV; next best step in Dx?
voiding cystourethrogram. Tx must do surgery.
6-month-old boy + one-day Hx of fever + pyuria + E.coli grown from urine culture + Abx initiated + renal ultrasound shows no abnormalities; next best step?
voiding cystourethrogram (check for posterior urethral valves).
3-month-old boy + fever + pyuria + few bacteriuria; next best step in Dx?
renal ultrasound; Dx most likely pyelonephritis (few bacteria typical on U/A despite pyuria); must do renal and bladder ultrasound for all kids age 2-24 months who have febrile UTIàscreens for congenital genitourinary tract abnormalities.
30-month-old boy + fever 101F + loose, bloody stools + tonic-clonic seizure; Dx?
shigellosis on Peds NBME; wrong answers are HUS and “idiopathic seizure disorder.”
16M + mouth ulcer + bloody diarrhea; Dx?
Crohn disease
14F + lower abdominal cramps and intermittent knee pain for 6 weeks + 6-10 bloody stools per day + WBCs and platelets elevated + arthrocentesis is normal; Dx?
UC
frequently associated with arthritis; high WBCs characteristic of autoimmune flares; thrombocytosis can be seen in infections and/or autoimmune flares; next best step in Dx = colonoscopy; Tx is initially with 5-ASA compounds (mesalamine) and steroids; colectomy can be curative in severe cases.
5F + hemophilia A; Q asks you directly how this is possible; answer =?
lyonization (skewed X- inactivation); you will never see an XR disorder in a female unless the explicit purpose of the question is lyonization.
4M + watery diarrhea two weeks ago + now has heavier diarrhea and bloating and flatulence with meals; Dx?
secondary lactose intolerance caused by sloughing of brush border following gastroenteritis (rotavirus).
5F + positive screen for Celiac Ab; next best step?
(answers are either duodenal biopsy, or no further studies indicated) answer = duodenal biopsy (shows flattened villi); sounds wrong, but it’s what NBME wants.
best way to decrease chance of developing allergy to food protein?
Exclusively breastfeed for the first 6 months
Treatment for baby/infant with milk or soy protein allergy on USMLE is?
switch to hydrolyzed
formula”
Milk protein allergy Dx can be made with skin prick and patch tests.
.
16-month-old male + Giardia infection + failure to thrive; Q asks mechanism for failure to thrive; answer?
“malabsorption of fats and carbohydrates”; Tx Giardia infection with metronidazole.
3M + hard nodule on testis + serum AFP + beta-hCG are elevated; Dx?
mixed germ cell tumor (embryonal cancer)
3M + hard nodule on testis; Dx?
yolk sac tumor (endodermal sinus tumor) -> serum AFP may be elevated.
14M + dragging sensation of left testis + soft tissue mass at top of left testis that disappears when supine; patient is at increased risk of what?
answer = infertility; Dx = varicocele.
