Pediatrics #5

 

HY lecture notes:

ToRCHeS:

Toxo –> triad of hydrocephalus, intracranial calcifications, chorioretinitis

Other –> Parvo B19 (aplastic anemia; hydrops), Varicella (zigzag skin lesions, limb defects, micro-ophthalmia)

Rubella –> patent ductus arteriosus (PDA), cataracts, deafness

CMV –> deafness, intracranial calcifications, hepatomegaly, blueberry muffin rash (non-specific);

Dx of CMV is diagnosis of exclusion in vignettes –> Q will say “intracranial calcifications” but won’t mention the other components of the Toxo vignette; there will also be no mention of classic Rubella, Syphilis, Parvo complications, etc., so you’re left with CMV. Although deafness is non-specific and can occur in congenital rubella and syphilis, it’s nevertheless exceedingly HY for congenital CMV and any pediatrician will drill that.

Herpes/HIV –> if woman has herpetic Sx (i.e., tingling, burning, etc.; she does not need to have active/visible vaginal lesions), must do C-section on USMLE. For HIV, give mother HAART during pregnancy (most important way to decrease risk of vertical transmission), give her intrapartum zidovudine, deliver fetus by C-section, then give fetus intrapartum zidovudine within 12 hours. The latter is asked specifically on one of the peds forms (i.e., the answer is literally “give neonate zidovudine within 12 hours”).

Syphilis –> saddle nose, Hutchinson incisors, saber shins, keratitis, deafness.

Iron deficiency in peds is HY for kids fed more than 24 ounces of cows milk daily. Why this detail is so HY I don’t know, but it’s asked. Or the vignette will simply mention a kid is on cows milk + they’ll show you a smear of pale RBCs, and expect you to know the Dx is iron deficiency. Not super complicated, but important to mention.

Kids with sickle cell require folic acid supplementation even when MCV is normal. So you’ll get a vignette of, e.g., 2-year-old with SS + no overt problems; Q asks “what should he/she be supplemented with?” Answer = folic acid (B9), even when MCV is normal. This probably is because of increased RBC turnover –> increased folate requirement.

Turner syndrome –> female, 45XO, coarctation of the aorta, bicuspid aortic valve (aortic stenosis later), scattered nevi, cystic hygroma (lymphatic insufficiency + webbed neck), infertile (streak ovaries, but can reproduce via IVF –> behavioral science USMLE Qs); Tanner stage 1 (or rarely 2); bone age = chronologic age (genuine short stature –> usually a girl 4’11”).

Constitutional short stature –> bone age < chronologic age –> i.e., right-shifted growth curve –> will catch up, but is merely slow to start –> vignette will be 14M who is 4’10” freshman year of high school + parents are average height; next best step is getting the parents’ growth charts if possible –> or if that’s not listed, choose “get bone age.” I have seen one 2CK NBME Q where they didn’t mention bone age anywhere in the Q or As, but they mentioned the kid was, e.g., 4’11” freshman year of high school + Tanner stage 2 –> implication being: he clearly has a long way to go in terms of growth.

Achondroplasia –> postural height is normal –> torso is normal height, but merely limbs are short. FGFR3 mutation.