PGIM MD Paediatrics common mistakes
PGIM MD Paediatrics · Understand the traps and how to avoid them.
Reading a vignette and immediately selecting the first diagnosis that fits the headline symptom (e.g., 'fever plus rash' → measles) without checking the discriminating features the stem deliberately supplies (rash sequence, Koplik spots, conjunctivitis, vaccination status).
Time pressure and pattern-recognition bias lead candidates to anchor on the salient symptom and skip the second half of the stem, where the distractor is usually excluded.
What to do instead
Before answering, write down the two or three features in the stem that must be explained, then test each option against all of them. Reject any option that leaves a stated feature unexplained.
Confusing the age-specific normal ranges and physiological differences in neonates, infants, and older children (heart rate, respiratory rate, haemoglobin, blood pressure, urine output), and applying adult thresholds to a paediatric stem.
Adult medicine habits dominate; candidates memorise a single set of 'normal' values and do not recalibrate by age band.
What to do instead
Build a one-page age-band table (neonate, 1–12 months, 1–5 years, 5–12 years, adolescent) for vitals, Hb, and fluid rates, and rehearse it against sample stems until thresholds are automatic.
Incorrectly calculating paediatric drug doses and fluid volumes: using weight-based mg/kg without checking the maximum dose, misplacing the decimal, or using Holliday-Segar maintenance without subtracting ongoing losses or adjusting for dehydration.
Arithmetic is done mentally under time pressure, and candidates skip the safety step of comparing the calculated dose to the maximum adult dose.
What to do instead
Always show the calculation on the scratchpad, state the weight used, and finish with a maximum-dose check. Practise a fixed set of maintenance, bolus, and resuscitation calculations until the steps are habitual.
Missing the non-accidental injury red flags in a trauma or injury stem (inconsistent history, delay in presentation, injury pattern not matching developmental stage, repeated presentations) and treating the case as an ordinary accident.
Candidates focus on managing the visible injury and do not systematically interrogate the mechanism, timing, and developmental plausibility.
What to do instead
Adopt a checklist for any injury stem: mechanism versus age, consistency of accounts, delay, previous injuries, and examination findings off the injury line. If any flag is present, the answer must include safeguarding action.
Failing to recognise the sick child who needs immediate resuscitation: spending time on diagnostic workup in a stem describing lethargy, poor perfusion, grunting, or a non-blanching rash instead of selecting the resuscitation or escalation step.
Examination-style questions often reward diagnosis, so candidates default to the diagnostic option even when the stem is testing prioritisation of immediate management.
What to do instead
Sort options by urgency first: any 'call for help / start resuscitation / give antibiotics now' option is evaluated before diagnostic options. Learn the paediatric sepsis and anaphylaxis first-hour bundles as fixed sequences.
Mismanaging the newborn jaundice stem: not applying age-in-hours to the treatment threshold, confusing physiological with pathological jaundice timing, or omitting the need to check bilirubin against a chart rather than a single number.
Candidates memorise 'jaundice after 24 hours is physiological' and stop there, ignoring that the threshold for phototherapy depends on postnatal age in hours and risk factors.
What to do instead
Practise plotting bilirubin against age in hours on a treatment threshold chart, and memorise the pathological timing boundaries (within 24 hours, prolonged beyond 14 days in term infants) as absolute triggers for investigation.
Confusing developmental milestones across domains (gross motor, fine motor, language, social) and misjudging the significance of a single missed milestone versus a consistent delay or regression.
Milestone lists are memorised as a flat set of ages without the concept of red flags, loss of skills, and the difference between variation and delay.
What to do instead
Learn milestones as age-band tables with a 'red flag at this age' column, and practise distinguishing isolated delay from global delay and regression, which always warrants urgent assessment.
Misapplying immunisation knowledge: wrong schedule age for a given vaccine, failing to recognise a true contraindication versus a precaution, or not identifying the catch-up action for a child who is behind.
Schedules change and candidates rely on outdated memory rather than a current national schedule, and they conflate live vaccines with inactivated ones when assessing contraindications.
What to do instead
Keep a current national immunisation schedule and a short contraindication table (live vaccines in immunosuppression and pregnancy; anaphylaxis to a component). Rehearse catch-up scenarios explicitly.
Choosing the wrong investigation or over-investigating: ordering a CT or invasive test when a clinical diagnosis or a first-line non-invasive test is the correct next step, or omitting the test that changes management in a suspected metabolic or genetic case.
Candidates equate thoroughness with correctness and select the most definitive test rather than the appropriate next step in the pathway.
What to do instead
For each common presentation, memorise the first-line investigation and the one test that changes management. Ask 'what will I do differently with this result?' before selecting any investigation.
Ignoring the communication and safeguarding dimension of a stem: answering only the biomedical question when the scenario tests breaking bad news, consent, adolescent confidentiality, or escalation to a child protection team.
Candidates from a biomedical background treat communication and ethics items as filler and pick the option that sounds most clinically active rather than the most appropriate professional response.
What to do instead
Treat communication and safeguarding items as a distinct domain: practise the standard sequences (explain, explore concerns, agree a plan; escalate concerns rather than investigate alone) and always choose the option that involves the child and family and documents the escalation.