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USMLE Step3 Pediatrics

Subjects : health-sciences, usmle-step-3

Instructions:

Answer 50 questions in 15 minutes.
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Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. differentiate between central and peripheral precocious puberty
Central-increased androgen - inc GnRH; peripheral-increased androgenq(acne - growth acceleration) dec GnRH (due to feedback)
SCFE - stable-if patient can bear weight; unstable-if cannot ambulate; complications avascular necrosis; dx xray tx immediate int fixaton
Sydenhams chorea - 1-8m after rheumatic fever; may not recall h/o sore throat; tx oral penicillinX10d if allergic erythromycin; prophylaxis until adulthood; if motor function severely compromised - give haloperidol - valproic - phenobarbital
Iron overload from excessive transfusion and ineffective hematopoisis; many raw material but no products

2. 18mo bilat breast enlargment - some pubic hair
Thrombocytopeni - micorangiopathic hemolytic anemia - neurolotgical signs - RF - fever ; p/w PPPP pallor - petechia - pever - pailure tx plasmpheresis
Benign permature thelarche; expectant management
After 24h of abx therapy
Marfans - ehlers danlos - homocystinuria

3. physiological jaundice
T for t ; thalassemia; inc serum iron and Iron binding
Dx US tx; correct serum electrolyte - pyloromyotom
Middle ear effusion persists 3 m after OM; if no symptoms - just watch - if symptoms add another abx. if no improvement tympanocenesis/myringotomy
24h to 7d of birth

4. 3yo - never able to walk
Candidal diapar rash; tx clotrimazol
Smoking alters mucosa - cilia - adenoid structure - make children susceptible to infection
Order CK to r/o muscular dystrphies; duchene- defect in dystrophin gene; 10-20 times increased serum CK; LDH and aldolase also hight; dx electromyograpy and bx
Sydenhams chorea - 1-8m after rheumatic fever; may not recall h/o sore throat; tx oral penicillinX10d if allergic erythromycin; prophylaxis until adulthood; if motor function severely compromised - give haloperidol - valproic - phenobarbital

5. When to do surgery for undescended testes
Wait until 6 months
refuse
Absence seizure; tx ethosuximide
No intervention; 90% foreign bodies pass without difficulty

6. Parvovirus
TB - breastfeeding - asymptomatic hiv
Feeding jauding due to lack of feeding; 1st week; tx support; milk jaundice due to milk; afer 7d; lack of glucoronidase; incre unconjugate biill tx; interrupt feeding resume
Yes; but it will be less effective
Fifth disease; febrile syndrome

7. cleft lip but no cleft palate
Use of teratogenic agents like alcohol during pregnancy; reconstruction at 3m; rule of 10; 10ib - 10w and 10g hb
R/o serious disorder; Hirschprug's disease; CF - hypothyroidism; then tx MgOH
Bacterial: sudden onset - high fever - cxr consolidation. viral; gradual onset - diffuse bilat infhiltrate tx; bact-amoxi;
Hx hearing loss - meningitis - recurrent or persisten OM >3m - IU infection - ototoxic meds

8. penicillin effective against pseudomonas
Lateral neck xray in epiglottitis show swollen epiglottis
Infection in aqueus and vitreous humors; posttraumatic - postcataract surgery;
Less than 5th percentile
Pipercillin (zosyn) - ticarcillin

9. 12y - obese - hip pain - hip ext rotated
Croup
Splenic sequestraion crisis - aplastic crisis - hyperhemolytic crisis
Constitutional pubertal delay
SCFE - stable-if patient can bear weight; unstable-if cannot ambulate; complications avascular necrosis; dx xray tx immediate int fixaton

10. the recommended ca supplementation
Lateral neck xray in epiglottitis show swollen epiglottis
9-18yrs; 1300 mg; 19-50;l 1000mg; >50 1200mng
Tx only symptomatic carrier
Order CK to r/o muscular dystrphies; duchene- defect in dystrophin gene; 10-20 times increased serum CK; LDH and aldolase also hight; dx electromyograpy and bx

11. echymoses with low platelet <30k
Decr calorie intake; decr calorie absorption;incr calorie demand
Prednisone/methyleprednison; IVIG - chronic ITP-spelenctomy
Hospital admission - NG feeding - purgative botulinum antitoxin - no abx (they cause lysis of spores--release more toxin) -
Tonsilar exudate - tender cervical nodes - fever - no cough/nasal dischr (suggest viral inf)

12. horner syndrom
Injury to lower roots of brachial plexus
Splenic sequestraion crisis - aplastic crisis - hyperhemolytic crisis
Multiple telangiectesia - vasular lesion in CNS
No myoclonic activity in JME

13. red oozing rash on cheek - scaly - dry
Atopic dermatitis; strong allergic/immunologic component; incr IgE
Mainly clinical; serology with initial ELISA - with western blot confirmation;
Strep pneumonie; moraxella; h influenze
Marfans - ehlers danlos - homocystinuria

14. When to bevioral and enviromental measure in led intoxication?
Cholesterol--pregnenolore---->17 Oh pregnenolone--->dehydroepiandosterone - pregnenolone--->progesterone--->dexoycorticosterone->corticosterone--->aldosterone -17 oh pregnenolone--->17 0Hprotesteronee--->cortisol - dehydroepiandosterone--->androstene
<44 - CBC - Electrolyte - and urinanlysis; if >44 oral chelation; >70 hospitalization and parenteral chelation
Faciform RBC cause vascular occlusion
Medical emergency; dimercaprol/edta

15. Tx of community acquired pneumonia
Central isosexual precocious puberty; hypothalmaic hamartoma
GERD - try thickened formula if no improvement - H2 antagonists - last resort surgery
Bugs; strep pneumonia - mycoplasma; give ceftriaxone and azithro
14yrs

16. dx of lyme
Herpes
Mainly clinical; serology with initial ELISA - with western blot confirmation;
Males - weak stream - bladder distension - bladder wall thickening - vesicoureteral reflex; most common caUse of obstructive uropathy in children dx cystourethrogram
Dactylitis; 2nd common is splenic seqestration

17. 17 alpha hydroxylase
Neonatal chlamydia; time after birth important. develops 3-10 week after delivery
D for d; down syndrome and polyhydramnios
Erythromycin (used for pertusis prophylaxis) or macrolides in breastfeeding child
Between pregnenolone and 17oh pregnenolone

18. Infant with serum billlirubin >25
Strep pneumonie; moraxella; h influenze
Risk of neurological dysfunction
At least 5 of 9 symptoms: DIGFAST depressed mood - insomnia - guilt - f - anhedonia - suicidal ideation -
Croup; hx coughx2-3d - gradual onset; high fever; barking cough; <3y; epiglotitis; sudden onset; stridor; >3y

19. How to differentiate croup vs epiglotitis
Develops in 21 dasy
Less than 5th percentile
Croup; hx coughx2-3d - gradual onset; high fever; barking cough; <3y; epiglotitis; sudden onset; stridor; >3y
Absence seizure; tx ethosuximide

20. child with triad of abd pain - mucoid curant jelly stools - and palpable mass in abd
Endocardial cushion defect (no separation between heart chambers)
Biliary atresia; tx surgery
Intussuseption; dx Us: tx enema comlication; perforation <1% if patient <6m and symptoms presented 3d; have SBO
Herpes

21. contraindications of MMR vaccine
Increase of pregnenolone
Feeding jauding due to lack of feeding; 1st week; tx support; milk jaundice due to milk; afer 7d; lack of glucoronidase; incre unconjugate biill tx; interrupt feeding resume
Males - weak stream - bladder distension - bladder wall thickening - vesicoureteral reflex; most common caUse of obstructive uropathy in children dx cystourethrogram
Current moderate of severe fever; anaphylaxis to gelatin/neomycin; immunodeficiency(hiv - chemo); thrombocytopenia; recent administration of immunoglobulin (can diminish efficacy); preganancy

22. indications of audiometry in childrens
Hx hearing loss - meningitis - recurrent or persisten OM >3m - IU infection - ototoxic meds
After 6m; breast mild provides iron until 6m.
Rash distribution same; measles-3C - cough - conjunctivitis - coryza; koplik spot; rubell; LG fever. lymphadenopahty - tx; self limiting
Anaphylaxis or encephalopathy within 7d of administration; temporary contraindications moderate to severe illness

23. How to dx post uretheral valve
Neurofibromatosis type2
Males - weak stream - bladder distension - bladder wall thickening - vesicoureteral reflex; most common caUse of obstructive uropathy in children dx cystourethrogram
Faciform RBC cause vascular occlusion
Black

24. How to difference aplastic vs hyperhemolytic/spleenic sequetratoin crisi
<2yrs - abd pain - diarrhoea - ARF
<44 - CBC - Electrolyte - and urinanlysis; if >44 oral chelation; >70 hospitalization and parenteral chelation
Atypical lymphocyte
No reticulocyte vs high reticulocyte

25. when bact conjunctivitis patient can go back to school
After 24h of abx therapy
Dactylitis; 2nd common is splenic seqestration
Prolactinoma
Mainly clinical; serology with initial ELISA - with western blot confirmation;

26. When to do aortic root surgery in marfans to prevent dissection?
If aortic root reaches 45 mm
Spores of c boutlium; colonizes in GI tract; release neurotoxin which blocks presynaptic cholinergic transmission; dysfunction of skeletal and smooth muscles
1.5%
Lateral neck xray in epiglottitis show swollen epiglottis

27. How to dx RSV
Increase of progesteron/17oh progesterone
Mainly clinical; serology with initial ELISA - with western blot confirmation;
Rapid detection of RSV antigen in nasl
Erythromycin ointment - sulfa drops - polymyxin /trimethoprim drops

28. tuberous sclerosis
<5 febrile UTI. males after first UTI - females <3yrs after first UTI - UTI unreponsive to abx - recurrent UTI
Hypopigmented macule - glial proliferation - organ haramtomas/cysts
<2yrs - abd pain - diarrhoea - ARF
TB - breastfeeding - asymptomatic hiv

29. Nocturnal enuresis
If <7 reassure parents; use alarms - desmopressin and tricyclics less effective than alarms
Use of teratogenic agents like alcohol during pregnancy; reconstruction at 3m; rule of 10; 10ib - 10w and 10g hb
Absence seizure/epilepsy: normal EEG - no myoclonic activity; prognosis good if no generalized seiure
No; they are basic compound will be neutralized in an acidic environment of cellulitis

30. carditis and arthritis after rheumatic fever
If <7 reassure parents; use alarms - desmopressin and tricyclics less effective than alarms
Develops in 21 dasy
Current moderate of severe fever; anaphylaxis to gelatin/neomycin; immunodeficiency(hiv - chemo); thrombocytopenia; recent administration of immunoglobulin (can diminish efficacy); preganancy
Angulation in forward bending think about structural problem; will not be corrected on its own; tx milwakee brace

31. giardiasis
Infection in aqueus and vitreous humors; posttraumatic - postcataract surgery;
T for t ; thalassemia; inc serum iron and Iron binding
Tx only symptomatic carrier
Croup

32. congenital adrenal hyperplasi
Decreases height - expensive; reserved for severe cases of delayed puberty
Reduction of the severity of symptoms; prevention of rheumatic fever and suppurative complications
Neonatal chlamydia; time after birth important. develops 3-10 week after delivery
Cholesterol--pregnenolore---->17 Oh pregnenolone--->dehydroepiandosterone - pregnenolone--->progesterone--->dexoycorticosterone->corticosterone--->aldosterone -17 oh pregnenolone--->17 0Hprotesteronee--->cortisol - dehydroepiandosterone--->androstene

33. 3yo - febrile - left hip externally rotated
Transient synovitis or toxic synovitis; bilateral effusion; preceded by URI -
Refeeding syndrome; edema and heart failure; severe hypophosphatemia tx iv phosophate
Aferbrile pneumnia - c. trachomatic - mycoplasma - ureasplams - cmv - rsv; look for onset - if 2-19w - can be chlamydia if asso conjunctivitis dx; cx of nasal secretion - chlamydia pcr
Epiglotitis; staph - HiB tx: ceftriaxone/cefotaxime

34. adenovirus
Use of teratogenic agents like alcohol during pregnancy; reconstruction at 3m; rule of 10; 10ib - 10w and 10g hb
Order CK to r/o muscular dystrphies; duchene- defect in dystrophin gene; 10-20 times increased serum CK; LDH and aldolase also hight; dx electromyograpy and bx
URI
Pho for forward bending; forward defect; common finding has no adverse physical effect

35. starring spells 10-20sec
Feeding jauding due to lack of feeding; 1st week; tx support; milk jaundice due to milk; afer 7d; lack of glucoronidase; incre unconjugate biill tx; interrupt feeding resume
9-18yrs; 1300 mg; 19-50;l 1000mg; >50 1200mng
Absence seizure/epilepsy: normal EEG - no myoclonic activity; prognosis good if no generalized seiure
refuse

36. How to dx endopthalmitis
GERD - try thickened formula if no improvement - H2 antagonists - last resort surgery
Herpes
Imaging study to r/o VUR
Infection in aqueus and vitreous humors; posttraumatic - postcataract surgery;

37. adrenal tumor
Heterosexual precocious puberty in females; inc androgen and cortisol - virilization in females - cushing (incr cortisol)
Bugs; strep pneumonia - mycoplasma; give ceftriaxone and azithro
Thalassemia - congenital hemolytic anemia
GERD - try thickened formula if no improvement - H2 antagonists - last resort surgery

38. Neonatal unconjugated hyperbilirubine
Tx only symptomatic carrier
Croup; hx coughx2-3d - gradual onset; high fever; barking cough; <3y; epiglotitis; sudden onset; stridor; >3y
Reduction of the severity of symptoms; prevention of rheumatic fever and suppurative complications
Decreased UGT enzyme

39. impaired gag reflex
Injury to b/l glossopharyngeal. present in botulism
Injury to lower roots of brachial plexus
Tx only symptomatic carrier
Less than 5th percentile

40. dx for DDH
US and barlow test: attempt to dislocated unstable hip; sometimes make clunking sound;
Increase of pregnenolone
2wk to 6 months p/w poor feeding - hypotonia - weakness - loss of DTR; soucee raw honey and soil - canned food
Marfans - ehlers danlos - homocystinuria

41. aplasic crisis
Age<6 - no past h/o afebrile seizure - temp>38 - no cns infection - no metabolic disturbance
Parvovirus B19 infection---failure of erythropoisis---no reticulocytes
Bartonella henselae; complication is suppuration of lymph node
Risk of neurological dysfunction

42. flexible kyphosis
Pho for forward bending; forward defect; common finding has no adverse physical effect
Meconeum ileus; think about CF
Neurofibromatosis type2
Central isosexual precocious puberty; hypothalmaic hamartoma

43. difference between diaper dermatitis and rash
Rash involves crural folds - has hx of antibiotic tx - due to decrease in normal bact flora - tx clotrimazaol; dermatitis; opposite - no hx abx; tx zinc oxide
Bladder dysfunction; UTI and renal dysfunctoin
Males - weak stream - bladder distension - bladder wall thickening - vesicoureteral reflex; most common caUse of obstructive uropathy in children dx cystourethrogram
Fluoroqunoloes to kill pseudmonas which is a common pathogen in these patients

44. How to dx acute angle closure glaucoma
Evaluate other developmental delay (microcephaly - lead poisoing) screen for eye prob and audiometry
Decresed visio - sudden onset - seeing halos around light - headache - eye pain
Medical emergency; dimercaprol/edta
Decreases height - expensive; reserved for severe cases of delayed puberty

45. mech of botulism
Anaphylaxis or encephalopathy within 7d of administration; temporary contraindications moderate to severe illness
INH 9m if INH resistant rifampin 6m in children and 4m in adults
GERD - try thickened formula if no improvement - H2 antagonists - last resort surgery
Spores of c boutlium; colonizes in GI tract; release neurotoxin which blocks presynaptic cholinergic transmission; dysfunction of skeletal and smooth muscles

46. sudden onset of fever - difficulty in breathing
Absence of puberty sign by 14yrs; testicle <2.5cm dm;
Benign permature thelarche; expectant management
Epiglotitis; staph - HiB tx: ceftriaxone/cefotaxime
Epiglotitis by H influenze; inflammartory edema of the epiglottis that impinges airway--resp arrest; dx clinical; tx relieve obstruction - intubate

47. 4d old infant with dilated loop of bowel;; constipaion; ground glass mass abdomen
Less than 5th percentile
Neurofibromatosis type2
SCFE - stable-if patient can bear weight; unstable-if cannot ambulate; complications avascular necrosis; dx xray tx immediate int fixaton
Meconeum ileus; think about CF

48. how thalassemia die
Pipercillin (zosyn) - ticarcillin
Methylephenidate toxicity; cannot be stopped abruptly; taper
Iron overload from excessive transfusion and ineffective hematopoisis; many raw material but no products
Cholesterol--pregnenolore---->17 Oh pregnenolone--->dehydroepiandosterone - pregnenolone--->progesterone--->dexoycorticosterone->corticosterone--->aldosterone -17 oh pregnenolone--->17 0Hprotesteronee--->cortisol - dehydroepiandosterone--->androstene

49. sublottic narrowing
Oral DMSA or EDTA IV
Bacterial: sudden onset - high fever - cxr consolidation. viral; gradual onset - diffuse bilat infhiltrate tx; bact-amoxi;
Croup tx cool mist; racemic epi - corticosteroid
Transmits thought sneezing -coughling - singing - speaking by microscopic aerosol containg the organism; keep patient in resp isoloation until non-infectious (3 sputum acid fast smear negative)

50. thumb sign
Absence seizure/epilepsy: normal EEG - no myoclonic activity; prognosis good if no generalized seiure
Erythromycin (used for pertusis prophylaxis) or macrolides in breastfeeding child
Neonatal chlamydia; time after birth important. develops 3-10 week after delivery
Epiglotitis; staph - HiB tx: ceftriaxone/cefotaxime