Pediatrics — USMLE Step 3 Practice
Pediatrics on USMLE Step 3 covers well-child care, developmental milestones, childhood infections, neonatal emergencies, and management of common pediatric illnesses. Vaccine schedules and growth parameters are frequently tested.
Frequently Asked Questions
What are the key developmental milestones tested on USMLE Step 3?
2 months: social smile, tracks past midline. 4 months: laughs, holds head steady. 6 months: rolls over, babbles consonants. 9 months: pincer grasp beginning, stranger anxiety, 'mama/dada' nonspecific. 12 months: walks with support, 1-2 words specific. 18 months: 10-25 words, walks independently. 24 months: 2-word phrases, 50+ words.
What is the management of bacterial meningitis in a neonate on Step 3?
Neonatal meningitis (0-1 month): most common organisms are GBS, E. coli, Listeria. Treatment: ampicillin + cefotaxime (or ampicillin + gentamicin if cefotaxime unavailable). LP before antibiotics if not delaying treatment. Duration: 14-21 days for GBS; 21 days for gram-negative bacilli.
How do you recognize and manage pyloric stenosis?
Hypertrophic pyloric stenosis presents at 2-8 weeks with projectile non-bilious vomiting, olive-shaped mass in the epigastrium, and hypochloremic hypokalemic metabolic alkalosis (from vomiting). Ultrasound confirms (pyloric muscle thickness >4mm). Treatment: pyloromyotomy after correction of electrolytes and fluid resuscitation.
What vaccinations are given at the 2-month well-child visit?
At 2 months: DTaP (diphtheria, tetanus, pertussis), IPV (inactivated polio), HiB (Haemophilus influenzae type b), PCV13 (pneumococcal), RV (rotavirus — oral). Hep B second dose can also be given at 1-2 months. Most vaccines are IM; rotavirus is oral.
How do you evaluate a child with failure to thrive on Step 3?
Failure to thrive (weight <3rd percentile or crossing 2 major percentile lines) — categorize as organic vs. non-organic. Initial evaluation: dietary history, feeding observation, CBC, CMP, TSH, urinalysis, lead level. Most cases (70-80%) are non-organic (inadequate caloric intake). Organic causes: celiac disease, IBD, GERD, cystic fibrosis, congenital heart disease.
Related Articles
- High-Yield Pediatrics for USMLE Step 3: Milestones, Vaccines, and Neonatal Emergencies
Master pediatrics for Step 3 — developmental milestones, vaccine schedules, neonatal emergencies, common infections, and failure to thrive.
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