Membership of the Royal College of Paediatrics and Child Health (MRCPCH) General Paediatrics and Systems Medicine Syllabus

Why does transposition of the great arteries (TGA) present with severe cyanosis, and what drug maintains life pre-surgery?

In TGA the aorta arises from the RV and pulmonary artery from the LV, creating two parallel circulations; survival depends on mixing. Prostaglandin E1 (alprostadil) keeps the ductus arteriosus open; a balloon atrial septostomy improves mixing before arterial switch.

List the clinical signs of heart failure in an infant.

Poor feeding/sweating with feeds, faltering growth, tachypnoea, tachycardia, hepatomegaly, gallop rhythm, cardiomegaly and recurrent chest infections. Note: peripheral oedema is uncommon in infants (hepatomegaly is the key sign).

What is the most common cause of a regular narrow-complex tachycardia (SVT) in infancy and its rate?

Re-entry SVT (often via an accessory pathway, e.g. WPW), with heart rate typically $>220\,\text{bpm}$ in infants, narrow QRS, and little beat-to-beat variation.

What is the stepwise management of stable (haemodynamically stable) SVT in a child?

(1) Vagal manoeuvres (ice to face / Valsalva); (2) IV adenosine by rapid bolus with escalating doses; (3) if unstable or refractory, synchronised DC cardioversion. Adenosine causes transient AV block to break the re-entry circuit.

State the modified Jones criteria framework for diagnosing acute rheumatic fever.

Evidence of preceding Group A Strep infection PLUS either 2 major, or 1 major + 2 minor criteria. Major: carditis, polyarthritis, chorea, erythema marginatum, subcutaneous nodules. Minor: fever, arthralgia, raised ESR/CRP, prolonged PR interval.

List the diagnostic criteria for Kawasaki disease and its most serious complication.

Fever $\geq 5$ days plus $\geq 4$ of: bilateral non-purulent conjunctivitis, cracked lips/strawberry tongue, cervical lymphadenopathy, polymorphous rash, changes of extremities (erythema/oedema then desquamation). Complication: coronary artery aneurysms. Treat with IVIG + aspirin.

What are red-flag features of vomiting in an infant that point away from simple GORD?

Bile-stained (green) vomit, projectile vomiting, haematemesis, abdominal distension/tenderness, blood in stool, bulging fontanelle, faltering growth, or vomiting starting after 6 months — these suggest obstruction, sepsis or surgical pathology.

Describe the classic presentation, electrolyte/acid–base disturbance and management of pyloric stenosis.

Projectile non-bilious vomiting at 2–8 weeks, hungry infant, palpable 'olive' mass, visible peristalsis. Hypochloraemic, hypokalaemic metabolic alkalosis. Correct fluids/electrolytes first, then Ramstedt pyloromyotomy.

Name the commonest cause of acute gastroenteritis in children and the key management priority.

Rotavirus (now declining due to vaccination); norovirus also common. Priority is assessment/correction of dehydration with oral rehydration solution; avoid routine antibiotics and antidiarrhoeals.

List common causes of chronic diarrhoea by mechanism in childhood.

Toddler's diarrhoea (commonest, well child), post-gastroenteritis lactose intolerance, coeliac disease, cow's milk protein allergy, inflammatory bowel disease, and cystic fibrosis/pancreatic insufficiency.

What are the red flags in childhood constipation suggesting an organic cause rather than functional?

Failure to pass meconium within 48 h (Hirschsprung), onset $<6$ weeks, ribbon stools, abdominal distension/vomiting, faltering growth, abnormal lower limb neurology or spine (spina bifida), and abnormal anal position/anus.

Explain the mechanism of overflow soiling in functional constipation.

Chronic stool retention causes rectal distension and reduced sensation; liquid/soft stool leaks around the impacted faecal mass (overflow/spurious diarrhoea). Management: disimpaction with macrogol (osmotic laxative) then maintenance plus behavioural support.

What are the warning ('red flag') features in a child with recurrent abdominal pain that warrant investigation?

Pain waking the child at night, weight loss/faltering growth, GI blood loss, persistent vomiting, dysphagia, fever, mouth ulcers, perianal disease, family history of IBD/coeliac, and pain away from the umbilicus.

List the main causes of jaundice in a child beyond the neonatal period, by bilirubin type.

Unconjugated: haemolysis (e.g. spherocytosis, G6PD), Gilbert syndrome. Conjugated: viral hepatitis (A/B/C/E), autoimmune hepatitis, Wilson disease, drug-induced, and biliary obstruction. Conjugated jaundice is always pathological.

Differentiate IgE-mediated from non-IgE-mediated food allergy.

IgE-mediated: rapid onset (mins–2 h) urticaria, angioedema, vomiting, wheeze, anaphylaxis; diagnosed by skin-prick/specific IgE. Non-IgE-mediated: delayed (hours–days) eczema, GI symptoms (e.g. cow's milk protein allergy proctocolitis); diagnosed clinically by elimination/reintroduction.

What is the first-line antibiotic and imaging approach for a child under 6 months with a first UTI?

Treat with empirical antibiotics (e.g. trimethoprim/cephalosporin per local sensitivity). Per NICE, infants $<6$ months with a first UTI need an ultrasound; atypical or recurrent UTI prompts further imaging (DMSA for scarring, MCUG for reflux).

What is vesicoureteric reflux (VUR) and why does it matter?

Retrograde flow of urine from bladder to ureters/kidneys (graded I–V) due to abnormal vesicoureteric junction; predisposes to recurrent pyelonephritis and renal scarring (reflux nephropathy), which can lead to hypertension and CKD.

State the diagnostic triad of nephrotic syndrome and the commonest underlying histology in children.

Triad: heavy proteinuria, hypoalbuminaemia ($<25\,\text{g/L}$) and oedema (often with hyperlipidaemia). Commonest cause is minimal change disease (~90% steroid-responsive).

Contrast the typical features of nephritic vs nephrotic syndrome.

Nephritic: haematuria, hypertension, oligo­uria, mild proteinuria, red cell casts (e.g. post-streptococcal GN). Nephrotic: heavy proteinuria, hypoalbuminaemia, oedema, normal/low BP (e.g. minimal change disease).

Describe the classic triad of haemolytic uraemic syndrome (HUS) and its commonest trigger.

Microangiopathic haemolytic anaemia, thrombocytopenia, and acute kidney injury. Commonest cause is Shiga-toxin-producing E. coli O157:H7 following bloody diarrhoea; management is supportive (avoid antibiotics).

How are the causes of acute kidney injury (AKI) classified, with paediatric examples?

Pre-renal (hypovolaemia, sepsis, dehydration — commonest), renal/intrinsic (HUS, glomerulonephritis, ATN, nephrotoxins), and post-renal (obstruction — posterior urethral valves, stones).

How is hypertension defined in children and what is the commonest secondary cause?

BP $\geq 95^{\text{th}}$ percentile for age, sex and height on $\geq 3$ occasions. Unlike adults, most paediatric hypertension is secondary — the commonest cause is renal/renovascular disease (e.g. reflux nephropathy, renal artery stenosis, coarctation).

What defines primary nocturnal enuresis and the first-line interventions?

Involuntary night-time wetting in a child $\geq 5$ years who has never been reliably dry. First-line after lifestyle/fluid advice: enuresis alarm; desmopressin for short-term/rapid control (e.g. sleepovers) or alarm failure.

How do you quantify clinically significant proteinuria in children?

Early-morning urine protein:creatinine ratio (uPCR) $> 20\,\text{mg/mmol}$ is abnormal; nephrotic-range is $> 250\,\text{mg/mmol}$. A 24-h collection $> 40\,\text{mg/m}^2/\text{h}$ is nephrotic. Orthostatic proteinuria is benign (absent in early-morning sample).

State the biochemical diagnostic criteria for diabetic ketoacidosis (DKA) in children.

Hyperglycaemia (blood glucose $>11\,\text{mmol/L}$), ketonaemia ($\geq 3\,\text{mmol/L}$) or significant ketonuria, and acidosis (venous $\text{pH} < 7.3$ or bicarbonate $< 15\,\text{mmol/L}$).

What is the most feared complication of DKA treatment in children and how is its risk reduced?

Cerebral oedema (the leading cause of DKA death in children). Risk reduced by cautious fluid rehydration over 48 h, delaying insulin until 1 h after fluids start, and avoiding rapid falls in glucose/osmolality; treat with hypertonic saline or mannitol.

How are the principal causes of congenital hypothyroidism and acquired hypothyroidism in children distinguished?

Congenital: thyroid dysgenesis/agenesis (commonest), dyshormonogenesis, iodine deficiency — detected on newborn screening (raised TSH), must be treated early to prevent intellectual disability. Acquired: most often autoimmune (Hashimoto) thyroiditis.

Define short stature and list the key 'pathological' patterns to recognise on a growth chart.

Height below the $2^{\text{nd}}$ centile (or $-2$ SD), or crossing down $\geq 2$ centiles. Pathological clues: low height velocity, height well below mid-parental target, or disproportion. Causes: familial/constitutional delay (commonest, normal velocity) vs endocrine (GH deficiency, hypothyroid), Turner syndrome, chronic disease.

Define precocious puberty and contrast central (gonadotrophin-dependent) vs peripheral types.

Onset of secondary sexual characteristics before age 8 (girls) or 9 (boys). Central (GnRH-dependent): early HPG-axis activation, raised LH/FSH, often idiopathic in girls. Peripheral (GnRH-independent): sex steroids from gonad/adrenal/tumour, suppressed LH/FSH (e.g. CAH, McCune–Albright).

Describe the typical presentation of classic salt-wasting congenital adrenal hyperplasia (21-hydroxylase deficiency).

Autosomal recessive 21-hydroxylase deficiency causes cortisol/aldosterone deficiency with androgen excess. Females: virilised/ambiguous genitalia. Both sexes: salt-wasting adrenal crisis at 1–3 weeks with hyponatraemia, hyperkalaemia, hypoglycaemia; raised 17-hydroxyprogesterone.

What clinical clues should prompt suspicion of an inborn error of metabolism in a neonate/infant?

Encephalopathy/lethargy, poor feeding and vomiting after a symptom-free interval, hypoglycaemia, metabolic acidosis with raised anion gap, hyperammonaemia, unusual odour, and a history of consanguinity or unexplained sibling deaths.

Use red cell indices to classify the anaemias and give a paediatric example of each.

Microcytic (low MCV): iron deficiency (commonest), thalassaemia. Normocytic: acute blood loss, haemolysis, anaemia of chronic disease. Macrocytic (high MCV): $\text{B}_{12}$/folate deficiency, hypothyroidism.

Contrast the inheritance and lab findings of haemophilia A vs von Willebrand disease.

Haemophilia A: X-linked recessive Factor VIII deficiency — prolonged APTT, normal PT/platelets, deep bleeds/haemarthroses. von Willebrand disease: autosomal dominant — mucocutaneous bleeding, prolonged bleeding time/APTT, low vWF and reduced platelet adhesion.

What is the commonest childhood malignancy, its peak age, and classic presenting features?

Acute lymphoblastic leukaemia (ALL), peak age 2–5 years. Presents with marrow failure: anaemia (pallor, lethargy), thrombocytopenia (bruising/petechiae), neutropenia (infection), plus bone pain, hepatosplenomegaly and lymphadenopathy.

What are the 'red flag' features of lymphadenopathy in a child that suggest malignancy?

Nodes $>2\,\text{cm}$, hard/matted/fixed, non-tender, supraclavicular location, persistent $>4$–$6$ weeks or progressively enlarging, plus systemic 'B' symptoms (fever, night sweats, weight loss) or hepatosplenomegaly.

Distinguish neuroblastoma from Wilms tumour (nephroblastoma) as childhood abdominal masses.

Neuroblastoma: arises from adrenal/sympathetic chain, may cross the midline, raised urinary catecholamines (VMA/HVA), under age 5. Wilms tumour: arises from kidney, usually does not cross midline, haematuria, associated with WT1 syndromes (WAGR, Beckwith–Wiedemann).

List the 'traffic light' / NICE red features that mark a febrile child as high risk for serious illness.

Pale/mottled/blue skin, no response to social cues / appears ill / weak high-pitched cry, grunting, RR $>60$, moderate–severe chest indrawing, reduced skin turgor, non-blanching rash, bulging fontanelle, neck stiffness, status/focal seizures, age $<3$ months with temp $\geq 38^{\circ}\text{C}$.

What are the commonest causes of bacterial meningitis by age group in children?

Neonates: Group B Streptococcus, E. coli, Listeria. Infants/children: Neisseria meningitidis and Streptococcus pneumoniae; Haemophilus influenzae type b now rare due to vaccination.

Interpret typical CSF findings in bacterial vs viral meningitis.

Bacterial: cloudy, raised neutrophils (polymorphs), high protein, LOW glucose (CSF:plasma ratio $<0.4$), high opening pressure. Viral: clear, lymphocytes, normal/mildly raised protein, normal glucose.

Match these childhood exanthems to their classic features: measles, rubella, erythema infectiosum, roseola, scarlet fever.

Measles: Koplik spots, descending maculopapular rash, coryza/conjunctivitis. Rubella: pink rash + suboccipital lymphadenopathy. Erythema infectiosum (parvovirus B19): 'slapped cheek'. Roseola (HHV-6): high fever then rash as fever resolves. Scarlet fever (Group A Strep): sandpaper rash, strawberry tongue, perioral sparing.

How does primary pulmonary tuberculosis typically present in children and what is the standard treatment regimen?

Often asymptomatic or with chronic cough, fever, weight loss, lymphadenopathy (Ghon focus + hilar nodes = primary/Ghon complex). Treatment: 2 months of Rifampicin, Isoniazid, Pyrazinamide, Ethambutol (RIPE), then 4 months Rifampicin + Isoniazid.

List the routine UK childhood immunisations given at 8, 12 and 16 weeks.

8 weeks: 6-in-1 (DTaP/IPV/Hib/HepB), MenB, rotavirus. 12 weeks: 6-in-1, pneumococcal (PCV), rotavirus. 16 weeks: 6-in-1, MenB. (MMR given at 1 year.)

What is the difference between live-attenuated and inactivated vaccines, with examples, and a key contraindication?

Live-attenuated (MMR, BCG, rotavirus, nasal flu, varicella): weakened organism giving strong durable immunity but contraindicated in significant immunosuppression/pregnancy. Inactivated/subunit (6-in-1, PCV, HPV): cannot replicate, safer in immunocompromise but often need boosters.

What pattern of infections suggests a primary immunodeficiency, and which type is most common?

Recurrent, Severe, Persistent, Unusual organisms/sites infections plus failure to thrive and family history ('SPUR'). Antibody (B-cell) deficiencies (e.g. selective IgA deficiency, common variable immunodeficiency) are the commonest, causing recurrent sinopulmonary bacterial infections.