---

Pediatrics Exam: 80/20 High-Yield Hacks

---

1. Developmental Milestones - Single Most-Tested Topic

• No social smile by 2 months
• No babbling by 12 months
• No single words by 16 months
• No 2-word phrases by 24 months
• Any regression at any age = investigate immediately

---

2. Neonatology (Highest-Yield Single Chapter)

• Physiologic: starts day 2-3, peaks day 4-5, resolves by day 7-10
• Pathologic: appears in first 24 hours → think hemolysis (ABO incompatibility, G6PD)
• Rule: jaundice on day 1 = blood type mismatch until proven otherwise
• Treatment thresholds: phototherapy → exchange transfusion (nomogram-based)

• Hypoglycemia in newborn → check glucose in any jittery/lethargic newborn
• Sepsis: GBS most common <7 days; Listeria rare but tested
• Umbilical hernia vs. omphalocele vs. gastroschisis (know which closes spontaneously)

---

3. Pediatric Infectious Disease - Memorize the "Classic Triads"

---

4. Congenital Heart Disease - Pattern Recognition

• Tetralogy of Fallot (most common) - harsh systolic murmur, tet spells relieved by squatting
• Transposition of Great Arteries - cyanosis at birth, no murmur, "egg-on-a-string" CXR
• Truncus Arteriosus
• Tricuspid Atresia
• Total Anomalous Pulmonary Venous Return

---

5. Pediatric Fluids and Electrolytes

• 0-10 kg: 100 mL/kg/day
• 10-20 kg: add 50 mL/kg/day for each kg above 10

• 20 kg: add 20 mL/kg/day for each kg above 20

• Mild (<5%): thirsty, normal exam
• Moderate (5-10%): dry mucous membranes, decreased skin turgor, tachycardia
• Severe (>10%): sunken fontanelle, mottled, no tears, delayed cap refill → IV bolus 20 mL/kg NS

---

6. Hematology Buzzwords

---

7. Vaccination Schedule - High-Yield Points Only

• Birth: Hep B
• 2, 4, 6 months: DTaP, IPV, Hib, PCV13, Rotavirus (oral)
• 12-15 months: MMR #1, Varicella #1
• 15-18 months: DTaP booster
• 4-6 years: MMR #2, DTaP #5, IPV #4
• 11-12 years: Tdap, HPV, MenACWY

---

8. Neurology Quick Wins

• Febrile seizures: 6 months - 5 years, <15 min, no focal features → reassure; do NOT give prophylactic anticonvulsants for simple febrile seizures
• Absence seizures: Blank staring + 3Hz spike-wave on EEG → ethosuximide
• Infantile spasms (West syndrome): <1 year, salaam spasms, hypsarrhythmia on EEG → ACTH or vigabatrin
• Reye syndrome: Aspirin in a viral illness → hepatic encephalopathy + fatty liver (why you never give aspirin to children <12)

---

9. The Meta-Hacks (Strategy Layer)

1. Question banks first, textbooks second. A 2024 PMC study showed the highest exam z-scores came from combining high-yield review materials + question banks. UWorld + Harriet Lane Handbook is the gold standard combination.
2. Do questions before "feeling ready." Reviewing questions wrong and reading the explanation beats passive reading by a wide margin.
3. Study in 15-20 topic blocks, not by organ system. Pediatrics exams mix topics within a single vignette - practice recognizing the pivot (e.g., "now the child develops renal failure" = HUS, not a separate topic).
4. Milestone questions are almost always about the red flag, not the normal. When the vignette gives you an "abnormal" child - always ask: is this 1 domain or 2+ domains? Isolated fine motor delay → occupational therapy. Two domains → refer to developmental pediatrician.
5. For congenital heart disease: If the baby is cyanotic and prostaglandin is given → it's a ductus-dependent lesion (TGA, pulmonary atresia, critical coarctation). This is a favorite "next step" answer.
6. For any pediatric "next step" question: The order is almost always - stabilize airway/breathing/circulation → diagnose → treat. Never jump to antibiotics without at least considering whether the airway is safe (epiglottitis is the classic trap).

---

Topics to Deprioritize (Low Yield)

• Rare inborn errors of metabolism (know the few classic ones: PKU, galactosemia, maple syrup urine disease - just the triad)
• Exact vaccine lot numbers / cold chain specifics
• Rare genetic syndromes beyond the big 5 (Down, Turner, Klinefelter, DiGeorge, Williams)
• Ophthalmology minutiae

---

Developmental milestones + Neonatal emergencies + Kawasaki/croup/epiglottitis triads + Congenital heart 5Ts + Holliday-Segar fluids + Febrile seizures + Vaccine contraindications + Question bank daily practice

---

Pediatric "Triad" Diagnosis Patterns - Exam Q&A Master List

---

HOW TO USE THIS

---

TIER 1 - Highest Frequency (Appear in Almost Every Exam)

---

1. Kawasaki Disease

Q trap: A child gets aspirin for Kawasaki. Is Reye syndrome a risk? Answer: No - aspirin here is given for its anti-inflammatory/antiplatelet effect at therapeutic doses under specialist guidance, not for a viral illness.

---

2. Intussusception

1. Colicky, intermittent abdominal pain (episodes 10-15 min, intervals 15-30 min)
2. Palpable sausage-shaped mass (RUQ/right abdomen)
3. "Currant jelly" stool (blood + mucus - ischemic mucosa) - late and infrequent

Exam trap: "All three features are present in a minority of patients." The question will likely give you 1 or 2 features. Pain + vomiting in a 6-18 month old = think intussusception first.

---

3. Hemolytic Uremic Syndrome (HUS)

1. Microangiopathic hemolytic anemia (schistocytes on blood film)
2. Thrombocytopenia
3. Acute kidney injury (oliguria, hematuria, rising creatinine)

Q trap: Should you give antibiotics for the STEC diarrhea? Answer: No - antibiotics increase Shiga toxin release and worsen HUS risk. Treatment is supportive.

---

4. Henoch-Schönlein Purpura (HSP / IgA Vasculitis)

1. Palpable purpura (below the waist - buttocks, lower limbs; non-thrombocytopenic)
2. Arthritis (knees and ankles)
3. Colicky abdominal pain ± GI bleeding

---

5. Pyloric Stenosis

1. Projectile, nonbilious vomiting after every feeding (1-6 weeks of age)
2. Palpable "olive" mass - firm, ovoid, 1-2 cm in epigastrium
3. Hypochloremic, hypokalemic metabolic alkalosis (from losing HCl in vomit)

Q trap: Vomiting is NONBILIOUS (obstruction is above ampulla of Vater). Bilious vomiting in a newborn = surgical emergency until proven otherwise (think malrotation/volvulus).

---

TIER 2 - Frequently Tested

---

6. Epiglottitis

1. Drooling
2. Dysphagia
3. Dyspnea (stridor, respiratory distress)
4. (+ Distress / high fever - often quoted as the actual 4th D)

---

7. Croup (Laryngotracheobronchitis)

1. Barky/seal-like cough
2. Inspiratory stridor
3. Hoarseness

---

8. Meningococcemia

1. Fever
2. Petechial/purpuric rash (non-blanching, trunk → spreading)
3. Meningismus (neck stiffness, photophobia)

---

9. Shaken Baby Syndrome / Abusive Head Trauma

1. Subdural hematoma (SDH)
2. Retinal hemorrhages
3. Encephalopathy (altered consciousness, seizures)

---

10. Meckel Diverticulum

1. Occurs in 2% of the population
2. Within 2 feet of ileocecal valve
3. Usually presents within first 2 years of life
4. (2 types of ectopic mucosa: gastric and pancreatic)
5. (2:1 male predominance)

1. Painless rectal bleeding (hematochezia)
2. Iron-deficiency anemia
3. Age <5 years

---

11. Tetralogy of Fallot

1. VSD (ventricular septal defect)
2. Overriding aorta
3. Pulmonary stenosis (RVOT obstruction)
4. Right ventricular hypertrophy

1. Cyanotic infant
2. Harsh systolic murmur (LLSB)
3. "Tet spells" (paroxysmal cyanosis during crying/feeding → child squats to relieve)

---

TIER 3 - Rarer but Classically Tested

---

12. Hand-Schüller-Christian Disease (Langerhans Cell Histiocytosis)

1. Lytic skull lesions
2. Exophthalmos (orbital bone involvement)
3. Diabetes insipidus (pituitary/hypothalamus involvement)

---

13. Prune Belly Syndrome (Eagle-Barrett / "Triad Syndrome")

1. Absent/deficient abdominal wall muscles
2. Bilateral cryptorchidism
3. Urinary tract abnormalities (dilated ureters, bladder, renal dysplasia)

---

QUICK EXAM DRILL TABLE

---

---

Long Answer Questions: Pediatric Infectious Diseases - Age-Specific Scenarios

---

QUESTION 1 - Neonatal Period (0-28 days)

Scenario

---

ANSWER

A. Diagnosis

• Prolonged rupture of membranes >18 hours (single most important risk factor)
• Maternal fever in labour (chorioamnionitis)
• Unknown GBS status
• Male sex (males have higher sepsis susceptibility)

---

B. Differential Diagnoses

1. Neonatal meningitis - always co-investigate; cannot be excluded without LP
2. Neonatal pneumonia - shares organisms with EONS; respiratory signs may dominate
3. Metabolic disease - inborn error of metabolism (rule out with metabolic screen)
4. Congenital heart disease - can present with poor feeding and cyanosis
5. Neonatal herpes simplex encephalitis - if maternal HSV history; vesicular rash
6. Hypoglycaemia alone - blood glucose is low here (2.1 mmol/L) but sepsis must still be excluded

---

C. Causative Organisms

• Group B Streptococcus (Streptococcus agalactiae) - most common; from maternal vaginal colonization
• Escherichia coli - especially in preterm; K1 antigen strains cause meningitis
• Listeria monocytogenes - uncommon but classically tested; associated with maternal consumption of unpasteurized dairy
• Haemophilus influenzae

• Same organisms as above, plus Staphylococcus aureus, coagulase-negative Staphylococci (especially NICU/indwelling lines)
• Meningitis more common in late-onset disease

---

D. Investigations

---

E. Management

1. Immediate Stabilisation (ABC)

• Airway: position, suction if needed
• Breathing: supplemental O₂ if SpO₂ <92%; CPAP or intubation if respiratory failure
• Circulation: IV access - umbilical venous catheter if peripheral access fails
• Temperature: incubator/radiant warmer for temperature instability
• Correct hypoglycaemia: 2 mL/kg of 10% dextrose IV bolus, then maintenance glucose infusion

2. Antibiotic Therapy (Start within 1 hour of suspicion)

Critical exam point: Avoid ceftriaxone in neonates - it displaces bilirubin from albumin-binding sites and can precipitate or worsen kernicterus. Use cefotaxime instead if a third-generation cephalosporin is needed (e.g., suspected gram-negative meningitis).

3. Duration of Antibiotics

• Bacteraemia without focus: 10-14 days
• GBS meningitis: 14-21 days (IV)
• Gram-negative meningitis: 21 days (IV)
• Culture-negative sepsis with good clinical response: 5-7 days (can discuss early de-escalation)

4. Supportive Care

• Maintain normothermia, normoglycaemia, normoxia
• Fluid management: 60-80 mL/kg/day day 1, increasing by 10-20 mL/kg/day
• Monitor for DIC, electrolyte disturbances
• Treat seizures: phenobarbitone (loading dose 20 mg/kg IV)
• Assess for complications: hydrocephalus (head circumference daily), hearing loss (OAE/BERA before discharge)

5. Prevention (Exam favourite)

• Intrapartum GBS prophylaxis: IV penicillin G to mother during labour if GBS-positive, prolonged ROM >18h, or maternal fever
• Universal GBS screening at 35-37 weeks gestation

---

QUESTION 2 - Infant (2 months - 1 year)

Scenario

---

ANSWER

A. Diagnosis

• Age 4 months - classic age for bacterial meningitis (beyond neonatal period, maternal antibody waning)
• High fever + bulging fontanelle + neck stiffness = meningeal irritation + raised ICP
• Non-blanching petechial/purpuric rash = pathognomonic feature of meningococcal disease
• Seizures: indicate cerebral irritation/encephalitis
• Haemodynamic compromise: septic shock component

• Bulging fontanelle (more reliable than neck stiffness in <12 months)
• Kernig's sign (straighten knee with hip flexed → pain/resistance)
• Brudzinski's sign (passive neck flexion → involuntary hip/knee flexion)
• Note: These are present in a minority of neonates but more reliable in older infants

---

B. Causative Organisms by Age

---

C. Investigations

• Cardiovascular instability / shock
• Seizures or focal neurology
• GCS <13 or rapidly deteriorating
• Raised ICP signs (papilloedema, unequal pupils)
• Coagulopathy

---

D. Management

1. Emergency Resuscitation

• A: Airway - intubate if GCS <8 or respiratory failure
• B: High-flow O₂
• C: 2 large-bore IV cannulas; 20 mL/kg 0.9% NaCl bolus for septic shock; repeat up to 60 mL/kg if needed; early vasopressors (dopamine/noradrenaline) if unresponsive
• Treat DIC: FFP, platelets, cryoprecipitate as needed
• D: Treat seizures: IV lorazepam 0.1 mg/kg → phenobarbitone 20 mg/kg if refractory

2. Antibiotics - Start IMMEDIATELY (within 30 minutes)

3. Dexamethasone

• 0.15 mg/kg IV q6h for 4 days, given 15-20 minutes before or with the first dose of antibiotics
• Reduces neuroinflammation; shown to reduce hearing loss in H. influenzae meningitis and neurological sequelae in pneumococcal meningitis
• Most benefit when given before antibiotics

4. Raised Intracranial Pressure Management

• Head of bed elevated 30°
• Avoid hypotonic fluids (risk of worsening cerebral oedema)
• Restrict fluids to 2/3 maintenance if SIADH is present
• Mannitol 0.25-0.5 g/kg IV if acute herniation signs

5. Duration of Antibiotics

6. Complications to Monitor

• Hearing loss (most common sequela - BERA test before discharge)
• Subdural effusion (suspect if fever persists >5 days on treatment)
• Hydrocephalus
• Cerebral infarction / focal deficits
• Adrenal haemorrhage (Waterhouse-Friderichsen syndrome in meningococcaemia)
• Limb ischaemia / gangrene in meningococcaemia

7. Chemoprophylaxis for Close Contacts

• Rifampicin 10 mg/kg q12h for 2 days (all household/close contacts of meningococcal disease)
• Alternative: single dose ciprofloxacin (adults) or ceftriaxone IM (preferred in pregnancy)
• Prophylaxis does NOT cover pneumococcal meningitis

---

QUESTION 3 - Toddler / Preschool (1-5 years)

Scenario

---

ANSWER

A. Diagnosis

---

B. Causative Organisms by Age

---

C. Investigations

---

D. Management

1. Immediate Stabilisation

• Supplemental O₂ to maintain SpO₂ ≥94%
• Nasal cannula/face mask; HFNC or CPAP if failing
• IV/NG fluid support if unable to feed orally
• Antipyretics: paracetamol 15 mg/kg q4-6h

2. Antibiotic Therapy

• Switch to oral amoxicillin (80-90 mg/kg/day in 2-3 divided doses) once clinically improving, afebrile for 24h, SpO₂ stable on room air
• Add anti-staphylococcal cover (cloxacillin or vancomycin) if: post-influenza, cavitation, pneumatoceles, or severe sepsis → suspect MRSA/PVL-SA

3. Management of Complications

• Ultrasound-guided pleural tap - diagnostic + therapeutic
• Chest tube drainage for empyema
• Intrapleural fibrinolytics (urokinase) if loculated
• IV antibiotics extended (3-4 weeks)
• Add cover for Staphylococcus if not already

4. Criteria for Discharge

• Afebrile for 24 hours on oral antibiotics
• SpO₂ ≥94% on room air
• Tolerating oral feeds
• Clinically improving

5. Prevention

• Pneumococcal conjugate vaccine (PCV13/PCV15) at 2, 4, 6, 12-15 months
• Influenza vaccine annually
• This child's lack of PCV vaccination was a modifiable risk factor

---

QUESTION 4 - School Age (5-12 years)

Scenario

---

ANSWER

A. Diagnosis

• Female sex (short urethra)
• Previous UTI (recurrence risk 30-50%)
• Need to investigate for vesicoureteric reflux (VUR) or anatomical abnormality

---

B. Causative Organisms

---

C. Investigations

Urine Collection (Critical - method determines validity)

• Positive dipstick (leucocytes + nitrites) AND
• Urine culture: ≥10⁵ CFU/mL of a single organism (clean catch) or ≥10⁴ (catheter)

Other Investigations

---

D. Management

1. Antibiotic Treatment

• Switch to oral cefalexin or co-trimoxazole once afebrile 24-48h and tolerating orally (guided by sensitivities)
• Oral amoxicillin-clavulanate is an alternative (check local resistance patterns - E. coli resistance to amoxicillin alone >50% in most regions)

2. Supportive Care

• IV fluids: maintain adequate hydration (oral if tolerating)
• Antipyretics: paracetamol ± ibuprofen
• Adequate analgesia for loin pain

3. Long-Term Management (Crucial for School-Age)

First febrile UTI in child >6 months
           ↓
Renal ultrasound within 6 weeks (urgent if atypical/recurrent)
           ↓
If abnormal or recurrent → MCUG (VUR grading)
           ↓
DMSA scan at 4-6 months post-infection (scarring assessment)

• Recurrent UTIs (≥2 episodes in 1 year)
• Grade III-V VUR
• Single functioning kidney

4. Bladder and Bowel Dysfunction (BBD)

• Screen for constipation and voiding dysfunction (extremely common cofactor)
• Treat constipation first - regular toileting, laxatives (polyethylene glycol)
• Bladder training: timed voiding, double voiding technique

5. Complications

• Renal scarring (reflux nephropathy) → hypertension, proteinuria, chronic kidney disease
• Recurrent pyelonephritis → progressive scarring
• Renal abscess (rare but occurs with delayed treatment)

---

QUESTION 5 - Adolescent (12-18 years)

Scenario

---

ANSWER

A. Diagnosis

• Travel to endemic area (South/Southeast Asia, Africa, Latin America) - essential context
• Step-ladder fever pattern - rises daily, falls partially overnight
• Relative bradycardia (pulse-temperature dissociation - Faget's sign)
• Rose spots - 2-4 mm blanching maculopapular spots on anterior trunk (pathognomonic; in ~30%)
• Constipation (early) - later may develop diarrhoea in week 2-3
• Splenomegaly
• Confusion / altered sensorium = typhoid encephalopathy - serious complication

• Malaria: cyclical fever, travel history overlaps - must exclude
• Dengue: haemorrhagic manifestations, thrombocytopenia, myalgia, no rose spots
• Infective endocarditis: heart murmur, embolic phenomena
• Infectious mononucleosis (EBV): pharyngitis, posterior cervical LN, monospot positive

---

B. Investigations

Definitive Tests

Supporting Investigations

---

C. Management

1. General Supportive Care

• Admit to hospital (this child is confused - severe disease)
• Bed rest, regular monitoring of vital signs
• Antipyretics: paracetamol (tepid sponging if needed)
• IV fluids if not tolerating orally or dehydrated
• Nutritious soft diet
• Isolation precautions: contact precautions; stool and urine are infectious
• Strict hand hygiene

2. Antibiotic Therapy

Exam point: Extensively drug-resistant (XDR) typhoid has emerged in Pakistan since 2016 (resistant to fluoroquinolones, ampicillin, chloramphenicol, co-trimoxazole, and 3rd-generation cephalosporins except ceftriaxone). Azithromycin is the current oral treatment for XDR typhoid.

3. Management of Complications

4. Monitoring Response

• Fever typically resolves in 3-7 days on ceftriaxone
• Failure to defervesce by day 5 → suspect resistance or complication → review cultures and sensitivities
• Repeat FBC, LFTs, blood culture at day 5-7

5. Prevention

• Typhoid vaccine: Vi polysaccharide vaccine (single IM dose, >2 years) or Ty21a oral live vaccine (>6 years) - recommended for travellers to endemic areas
• Food and water hygiene: eat thoroughly cooked food, drink bottled/boiled water
• Carrier state: Treat carriers (faecal excreters >12 months) with ciprofloxacin or ampicillin; may require cholecystectomy for chronic gallbladder carriers

---

EXAMINER'S MARKING GUIDE - What the Long Answer Must Include

Golden rule: Always start with ABC stabilisation before antibiotics, always state dose and route for every drug you mention, and always include age-appropriate causative organisms - these are the three commonest mark-losers.Your credits are exhausted. Your daily credits reset tomorrow, or you can purchase a top-up for more.