PLAB 1 (UKMLA AKT) paediatrics questions

Respiratory distress syndrome results from surfactant deficiency in type II pneumocytes, which are structurally and functionally immature before around 34-36 weeks' gestation. Without surfactant, alveolar surface tension rises, causing widespread alveolar collapse (atelectasis), reduced lung compliance and the classic ground-glass, air-bronchogram appearance on X-ray. Antenatal corticosteroids given to the mother accelerate fetal surfactant production, and exogenous surfactant can be given to the neonate after birth to reduce severity. This infant's prematurity, lack of antenatal steroids and X-ray findings are typical of RDS rather than the other listed mechanisms.

• A. This describes persistent pulmonary hypertension of the newborn, which is a separate entity usually following perinatal asphyxia or sepsis.
• C. Meconium aspiration occurs typically in term or post-term infants with meconium-stained liquor, not a 29-week preterm infant.
• D. This describes transient tachypnoea of the newborn, which is usually milder and resolves within 24-72 hours, not this infant's presentation.
• E. Congenital pneumonia can mimic RDS but is less likely given the strong prematurity risk factor and classic radiographic findings described.

Transient tachypnoea of the newborn (TTN) is caused by delayed clearance of fetal alveolar fluid, most common after elective caesarean section without labour, which normally triggers clearance mechanisms. It presents with tachypnoea and mild respiratory distress shortly after birth, with chest X-ray showing perihilar streaking and fluid in the fissures rather than diffuse ground-glass changes. Unlike RDS, TTN is typically self-limiting and resolves within 24-72 hours with supportive care such as supplemental oxygen if needed. The term gestation, delivery mode, mild symptoms and rapid resolution in this infant are characteristic of TTN.

• B. RDS occurs mainly in preterm infants due to surfactant deficiency and causes a diffuse ground-glass appearance with air bronchograms, not fissure fluid, and does not resolve this quickly.
• C. Congenital pneumonia would typically be associated with risk factors such as prolonged rupture of membranes or maternal fever, and would not resolve so rapidly without antibiotics.
• D. Persistent pulmonary hypertension causes severe hypoxaemia with differential cyanosis and does not resolve spontaneously within 36 hours.
• E. Meconium aspiration syndrome occurs with meconium-stained liquor and causes patchy atelectasis and hyperinflation, with a more severe and prolonged course.

Current UK Resuscitation Council guidance for newborn life support no longer recommends routine oropharyngeal or tracheal suctioning before initiating ventilation in non-vigorous meconium-stained infants, because this delays establishing effective breathing without proven benefit. The priority in a floppy infant with poor respiratory effort and heart rate below 100 beats/min is to open the airway and deliver five inflation breaths with air, moving promptly to assess chest movement and heart rate response. Only if the airway appears obstructed by thick meconium should direct visualisation and suction under direct laryngoscopy be considered, and this should not delay ventilation. Chest compressions are reserved for a heart rate below 60 beats/min despite adequate ventilation.

• A. Chest compressions are not indicated at this stage since the heart rate is above 60 beats/min and effective ventilation has not yet been established.
• B. Routine suctioning before ventilation is no longer recommended and delays essential inflation breaths in a floppy, poorly breathing infant.
• D. Simple stimulation is insufficient in an infant with a weak respiratory effort and bradycardia; effective ventilation is required.
• E. There is no indication of opioid-induced respiratory depression here, and naloxone is not part of standard newborn resuscitation.

Jaundice appearing within the first 24 hours of life is always pathological and requires urgent investigation, because it usually indicates a haemolytic process such as ABO or Rhesus incompatibility, G6PD deficiency, or sepsis. Measuring the serum (or transcutaneous, confirmed by serum) bilirubin establishes the level and rate of rise, while a direct Coombs test (direct antiglobulin test) helps identify immune-mediated haemolysis, which is common with maternal group O and an infant of a different blood group. Prompt diagnosis is essential because unconjugated bilirubin can rise rapidly in haemolytic disease, increasing the risk of kernicterus if untreated. Physiological jaundice by definition does not appear before 24 hours of age.

• A. Breastfeeding advice is appropriate for suspected breast milk jaundice, which presents later and is a diagnosis of exclusion, not for jaundice in the first day of life.
• B. Biliary atresia presents with prolonged conjugated jaundice beyond 2 weeks of age, not jaundice within the first 24 hours.
• D. Jaundice within the first 24 hours is never considered physiological and must not be dismissed without investigation.
• E. Phototherapy may ultimately be needed but should only be started once the bilirubin level is measured and plotted against the treatment threshold chart.

Jaundice persisting beyond 14 days in a term infant (or 21 days in a preterm infant) is termed prolonged jaundice and requires a split bilirubin to differentiate unconjugated from conjugated causes. Breast milk jaundice, the most common cause of prolonged unconjugated jaundice, is a diagnosis of exclusion in a thriving infant with normal-coloured stools and urine, and typically resolves by 12 weeks of age. A raised conjugated fraction, or the presence of pale stools and dark urine, would instead point towards biliary atresia and prompt urgent same-day ultrasound and surgical referral. This infant's normal stool and urine colour and good weight gain make breast milk jaundice far more likely than biliary atresia, but the split bilirubin must be checked first to confirm this.

• A. Liver biopsy is invasive and reserved for cases where biliary atresia or other hepatic pathology is suspected after initial investigations.
• B. A HIDA scan is used to assess bile flow when biliary atresia is strongly suspected after initial bilirubin fractionation, not as a first-line test.
• C. Ultrasound is useful if conjugated hyperbilirubinaemia or biliary atresia is suspected, but the split bilirubin should be checked first to establish this.
• E. There is no clinical suggestion of urinary tract infection such as fever or poor feeding, so this is not the most useful next test.

The NICE threshold charts plot serum bilirubin against postnatal age in hours, with separate lines for starting phototherapy and for exchange transfusion, specific to gestational age. This infant's bilirubin of 290 micromol/L lies above the phototherapy line (250 micromol/L) but well below the exchange transfusion line (400 micromol/L) at 50 hours, so phototherapy is the correct treatment. Phototherapy converts unconjugated bilirubin in the skin into water-soluble photoisomers that can be excreted without conjugation, lowering serum levels. The bilirubin level should be rechecked after 4-6 hours of phototherapy and then at least daily to confirm response and to decide whether treatment can be stopped.

• A. Intravenous immunoglobulin is an adjunct used in Rhesus haemolytic disease alongside phototherapy, not as a sole treatment, and is not indicated based on threshold alone.
• B. The bilirubin already exceeds the phototherapy threshold, so starting treatment now rather than waiting 24 hours is required to prevent further rise.
• C. Discharge is inappropriate since the bilirubin exceeds the treatment threshold for this postnatal age and gestation.
• E. Exchange transfusion is only indicated when the bilirubin reaches or exceeds the exchange transfusion line, which is not the case here.

This infant meets criteria for moderate-to-severe hypoxic-ischaemic encephalopathy: severe perinatal acidosis (pH less than 7.00, base deficit greater than 16 mmol/L), low Apgar scores needing resuscitation, and clinical signs of encephalopathy including altered tone, absent reflexes and seizure-like activity. Therapeutic hypothermia, cooling the infant to 33-34°C for 72 hours, should be started as soon as possible and within 6 hours of birth, as earlier cooling improves the chance of reducing secondary neuronal injury and improves neurodevelopmental outcomes. MRI brain is useful for prognostication but is performed later, around day 4-14, and does not determine the decision to cool, which is based on clinical and biochemical criteria. Seizures occurring during HIE are treated with anticonvulsants alongside cooling, not as an alternative to it.

• A. MRI is used later for prognosis, not to decide whether to initiate cooling, and should not delay treatment.
• C. Anticonvulsants may be needed for seizures but do not address the underlying hypoxic-ischaemic injury; cooling is the priority intervention.
• D. Routine observation is inappropriate given clear evidence of moderate-to-severe encephalopathy requiring neuroprotective treatment.
• E. Cooling should begin as early as possible within the 6-hour window and should not be delayed for an EEG.

NICE guidance (NG195) recommends intravenous benzylpenicillin plus gentamicin as first-line empirical therapy for suspected early-onset neonatal infection, covering group B streptococcus, Listeria and most Gram-negative organisms acquired perinatally. This combination is synergistic against GBS and other streptococci, and gentamicin extends cover to Gram-negative organisms such as E. coli. Ceftriaxone is avoided in neonates because it displaces bilirubin from albumin and can precipitate with calcium-containing infusions, risking kernicterus and precipitation in blood vessels and lungs. Co-amoxiclav is also avoided in neonates due to an association with increased risk of necrotising enterocolitis in preterm infants.

• A. Co-amoxiclav is avoided in neonates because of an association with necrotising enterocolitis and does not reliably cover early-onset sepsis pathogens alone.
• C. Vancomycin and meropenem is reserved for late-onset sepsis with suspected resistant organisms, not first-line empirical early-onset treatment.
• D. Flucloxacillin and gentamicin is used for suspected staphylococcal infection, not first-line for early-onset sepsis.
• E. Ceftriaxone is contraindicated in neonates due to bilirubin displacement and risk of calcium precipitation.

This baby has features of a congenital diaphragmatic hernia (scaphoid abdomen, displaced heart sounds, respiratory distress), confirmed antenatally or clinically, which allows abdominal viscera into the thoracic cavity. Bag-mask ventilation should be avoided because it forces air into the stomach and bowel within the chest, causing further distension that compresses the already hypoplastic lung and worsens respiratory compromise. The correct approach is early elective endotracheal intubation with gentle ventilation, together with nasogastric tube placement on free drainage to decompress the gut. Umbilical catheters are used for monitoring and access as part of standard supportive care.

• A. Continuous pulse oximetry is standard monitoring and should be used, not avoided.
• B. Elective endotracheal intubation is the preferred method of securing the airway in CDH, avoiding bag-mask ventilation.
• C. A nasogastric tube is essential to decompress the herniated bowel and reduce lung compression, so it is indicated, not avoided.
• E. Umbilical venous catheterisation is useful for vascular access and is not harmful in this condition.

The clinical findings describe a positive Ortolani test, consistent with developmental dysplasia of the hip (DDH). Ultrasound of the hips is the investigation of choice in infants under 4-6 months because the femoral head is still largely cartilaginous and not well visualised on plain X-ray; ultrasound also allows dynamic assessment of hip stability. NIPE guidance recommends ultrasound for babies with an abnormal or equivocal clinical examination, a positive family history of DDH, breech presentation at or after 36 weeks, or breech delivery. Plain radiography becomes useful after around 4-6 months once the femoral head ossifies.

• B. Plain radiography is unreliable in early infancy because the femoral head is not yet ossified; it is more useful after 4-6 months of age.
• C. Arthrography is an invasive procedure occasionally used during operative management, not for initial diagnosis.
• D. CT involves significant radiation exposure and is not used for screening or initial diagnosis of DDH in infants.
• E. MRI is not first-line for DDH assessment in neonates; it is reserved for surgical planning in selected cases.

UK Department of Health guidance recommends exclusive breastfeeding (or formula feeding) for around the first 6 months of life, with solid foods introduced at around 6 months alongside continued breastfeeding or formula. This timing aligns with the infant's developmental readiness, including the ability to sit with support, improved head control, and the disappearance of the tongue-thrust reflex, and allows adequate iron stores from birth to begin depleting before complementary feeding provides additional nutrients. Starting solids significantly before 6 months increases the risk of aspiration and does not confer nutritional benefit in a well-growing infant. Weaning should begin alongside continued milk feeds, not after stopping them.

• B. Weaning should be introduced alongside continued breast or formula feeding, not after stopping milk feeds.
• C. Delaying until 9 months is later than recommended and risks inadequate nutrient and iron intake.
• D. 5 months is still earlier than the recommended age of around 6 months.
• E. Starting weaning at 4 months is earlier than UK Department of Health guidance recommends.

A fall of two or more centile spaces on the UK-WHO growth chart is one of the criteria used by NICE to define faltering growth and should prompt further assessment. This baby has dropped from the 50th to the 2nd centile, representing more than two centile spaces, despite normal length and head circumference, suggesting a primarily nutritional cause rather than a syndromic or endocrine one. The appropriate next step is a detailed assessment including feeding history, observation of a feed if possible, and examination for underlying illness, rather than reassurance or an unfocused intervention. Urgent admission is not indicated in a well, feeding infant without signs of acute illness or severe dehydration.

• B. The baby is clinically well with no signs of dehydration or acute illness, so immediate admission is not warranted.
• C. Changing formula without assessing the cause of growth faltering is not appropriate as a first step.
• D. Repeating in 6 months would delay necessary assessment of a significant centile drop.
• E. A drop of more than two centile spaces meets the threshold for faltering growth and should not be dismissed as normal variation.

Most infants can sit unsupported by around 8 months, and inability to do so by 12 months is considered a red flag for possible developmental delay. This finding, in combination with the absence of other expected gross motor milestones such as pulling to stand, warrants prompt referral for formal paediatric developmental assessment to identify an underlying cause, such as a neuromuscular or neurodevelopmental disorder. Early identification allows timely investigation and intervention, which improves outcomes in conditions affecting motor development. Reassurance or delayed review would risk missing a treatable or significant underlying condition.

• B. There is no indication of hearing impairment here; the concern is gross motor delay, which needs broader developmental assessment.
• C. Delaying review by 6 months risks missing early diagnosis and intervention for an underlying developmental problem.
• D. Failure to sit unsupported by 12 months falls outside the normal developmental range and should not be reassured without assessment.
• E. Home physiotherapy advice alone without specialist referral would not adequately investigate the underlying cause of delay.

Gower's sign and calf pseudohypertrophy in a young boy are classic for Duchenne muscular dystrophy. The first-line investigation is serum creatine kinase, which is markedly elevated (often >10-20 times normal) due to ongoing muscle fibre breakdown. A grossly raised CK supports the clinical suspicion and prompts referral for genetic testing to confirm the dystrophin mutation. Genetic testing is used to confirm the diagnosis after an abnormal CK, not as the initial screening test.

• B. MRI of the spine is used to investigate cord or nerve root pathology, not a myopathy.
• C. Muscle biopsy is invasive and now reserved for cases where genetic testing is inconclusive.
• D. Nerve conduction studies assess peripheral neuropathy, not primary muscle disease, and are not indicated here.
• E. Dystrophin gene sequencing confirms the diagnosis but is requested after an elevated CK, not as the first test.

Vitamin D deficiency causes reduced intestinal calcium absorption, leading to hypocalcaemia, which triggers a compensatory rise in parathyroid hormone. Secondary hyperparathyroidism increases renal phosphate excretion, causing hypophosphataemia, and stimulates osteoblastic activity, raising alkaline phosphatase. This combination of low calcium, low phosphate, raised ALP and raised PTH is the classic biochemical signature of nutritional rickets. Risk factors here include exclusive breastfeeding beyond 6 months without vitamin D supplementation and limited sun exposure.

• A. Hypoparathyroidism causes low PTH with hypocalcaemia and hyperphosphataemia, the opposite phosphate pattern seen here.
• B. Osteogenesis imperfecta presents with fractures and blue sclerae with normal calcium, phosphate and PTH.
• D. Chronic kidney disease typically causes hyperphosphataemia due to reduced renal excretion, not hypophosphataemia.
• E. X-linked hypophosphataemic rickets causes isolated hypophosphataemia with normal calcium and normal or low PTH, not secondary hyperparathyroidism.

A short father with delayed pubertal onset himself, a growth curve that tracks steadily along a lower centile, and an otherwise normal examination all point towards constitutional delay of growth and puberty, a normal variant. The most appropriate initial step is to confirm this pattern objectively by plotting serial height measurements and growth velocity on a growth chart, since a consistent growth trajectory parallel to the centile lines supports a constitutional cause rather than pathology. This simple, non-invasive step guides whether further investigation is needed before considering hormonal or genetic tests.

• B. Testosterone therapy is not started without confirming the diagnosis and is not first-line management even in confirmed constitutional delay.
• C. Urgent endocrinology referral is not required when the history and growth pattern are reassuring for a normal variant.
• D. IGF-1 testing is used to investigate suspected growth hormone deficiency, which is not suggested by this history.
• E. Karyotyping is reserved for short stature with dysmorphic features or suspicion of a chromosomal cause such as Turner syndrome, not for this reassuring picture.

This child has severe asthma that has not responded adequately to initial bronchodilator therapy and steroids, with persisting tachypnoea and recession despite treatment. BTS/SIGN guidance recommends continuing frequent nebulised salbutamol and ipratropium and escalating care by discussing with a senior paediatrician or paediatric intensive care unit when there is poor response to first-line treatment, as this indicates a risk of deterioration requiring intravenous therapies such as magnesium sulfate, salbutamol or aminophylline. Early critical care involvement avoids delay if the child continues to deteriorate.

• A. Inhaled corticosteroids are for long-term control, not for an acute attack, and do not replace systemic steroids already given.
• B. Montelukast has no established role in the acute management of a severe asthma attack.
• C. A chest X-ray is not routinely required unless there are signs suggesting a complication such as pneumothorax, and should not delay escalation of treatment.
• E. Discharge is inappropriate while the child still has significant respiratory distress and hypoxia despite treatment.

Episodic wheeze that occurs only in association with viral upper respiratory tract infections, with complete resolution of symptoms between episodes and no interval symptoms, is characteristic of viral-induced (episodic) wheeze in preschool children. This pattern, together with the absence of atopy, eczema or a family history of asthma, favours a viral trigger over true asthma, which typically features interval symptoms such as nocturnal cough, exercise-induced symptoms or multiple triggers. Many preschool children with viral-induced wheeze outgrow it by school age as airway calibre increases.

• B. Cystic fibrosis presents with failure to thrive, steatorrhoea and recurrent chest infections, not isolated episodic wheeze with normal growth.
• C. Gastro-oesophageal reflux causes symptoms related to feeding and may cause chronic cough, not episodic wheeze tied specifically to viral infections.
• D. Foreign body aspiration causes a sudden onset of unilateral wheeze or stridor following a choking episode, not a recurrent pattern linked to viral illnesses.
• E. Atopic asthma typically causes symptoms between infections too, such as night-time cough or wheeze with exercise, and is more likely with a personal or family history of atopy.

NICE guidance identifies persistent oxygen saturation below 92% on air as a clear indication for hospital admission in bronchiolitis, because it reflects clinically significant hypoxia requiring supplemental oxygen and monitoring. Other admission criteria include apnoea, severe respiratory distress, central cyanosis, and inadequate oral fluid intake (typically less than 50-75% of usual volume), but in this vignette the saturation level is the single most decisive abnormal finding. Crackles and wheeze are expected examination findings in bronchiolitis itself and do not by themselves indicate severity requiring admission.

• B. Wheeze is a typical auscultatory finding in bronchiolitis and does not alone indicate a need for admission.
• C. A short coryzal prodrome is the expected course of bronchiolitis and is not itself an admission criterion.
• D. Crackles are an expected clinical sign of bronchiolitis and do not independently indicate severity requiring admission.
• E. Age under 5 months can be a risk factor for severity but is less specific here than the measured hypoxia.

Bronchiolitis is a viral illness, most commonly caused by respiratory syncytial virus, and NICE guidance states that bronchodilators, corticosteroids, antibiotics and nebulised hypertonic saline have no proven benefit in otherwise healthy infants and should not be used routinely. Management is supportive, consisting of ensuring adequate fluid intake, monitoring oxygen saturation, and providing supplemental oxygen only if saturations fall below 92%. This infant currently has mild disease with saturations above the threshold for oxygen therapy and adequate feeding, so close monitoring alone is appropriate.

• A. Salbutamol has no proven benefit in bronchiolitis and amoxicillin is not indicated for a viral illness.
• B. Ipratropium bromide, like other bronchodilators, has no established role in the management of bronchiolitis.
• D. Hypertonic saline and antibiotics are not recommended in routine bronchiolitis management, as the illness is viral and self-limiting.
• E. Corticosteroids have not been shown to improve outcomes in bronchiolitis and are not recommended.

Croup is a clinical diagnosis based on a barking cough, hoarseness and stridor following a viral prodrome. A single dose of oral dexamethasone (0.15 mg/kg) is recommended for all children with croup, regardless of severity, as it reduces symptom duration, hospital admission and return visits. Nebulised adrenaline is reserved for moderate-to-severe croup with stridor at rest and significant distress. Antibiotics have no role because croup is viral.

• A. Nebulised adrenaline is reserved for severe croup with marked respiratory distress or stridor at rest, not mild cases.
• B. Croup is viral; intravenous antibiotics are not indicated and this child shows no signs of bacterial superinfection or epiglottitis.
• D. Nebulised budesonide is an alternative to oral dexamethasone only if the oral route is not tolerated; steroids should not be withheld.
• E. Oral amoxicillin has no role in viral croup.

This child's presentation, drooling, muffled voice, high fever, toxic appearance and absence of a barking cough, is classic for acute epiglottitis, most commonly caused by Haemophilus influenzae type b in unvaccinated children. Examining the throat or agitating the child can precipitate complete airway obstruction, so the throat must never be examined outside a controlled setting. The priority is to keep the child calm and urgently involve senior anaesthetic and ENT teams to secure the airway, ideally in theatre.

• A. Steroids and discharge are inappropriate; this is a airway emergency requiring senior input, not outpatient management.
• B. Examining the throat can trigger laryngospasm and complete airway obstruction and must be avoided.
• C. Imaging delays definitive airway management and is unnecessary when the clinical picture is classic for epiglottitis.
• E. Nebulised adrenaline is used for croup, not epiglottitis, and delaying senior airway support is dangerous.

The paroxysmal cough with post-tussive vomiting and inspiratory whoop in a young, incompletely immunised infant is highly suggestive of whooping cough (pertussis). Pertussis is a notifiable disease in the UK, and macrolides (such as azithromycin) are the first-line treatment if the cough has been present for less than 21 days, reducing infectivity. Young infants are at high risk of complications such as apnoea and pneumonia, so prompt treatment and public health notification are essential.

• A. A chest X-ray is not required to diagnose or treat classic pertussis and should not delay antibiotic treatment and notification.
• B. Pertussis in a young infant carries significant risk of apnoea and complications and should not simply be observed without treatment.
• D. Amoxicillin is not effective against Bordetella pertussis; a macrolide is required.
• E. Intravenous ceftriaxone is not first-line for pertussis and hospital admission for antibiotics alone is unnecessary if the infant is stable.

A sudden choking episode followed by unilateral wheeze and reduced air entry is classic for an inhaled foreign body, and inspiratory/expiratory chest X-rays are the first-line investigation, which may show air trapping, mediastinal shift or, less commonly, a radio-opaque object. Many foreign bodies are radiolucent, so a normal X-ray does not exclude aspiration, but it helps guide further management and is quick and widely available. Definitive diagnosis and removal require rigid bronchoscopy under general anaesthesia if clinical suspicion remains high despite normal imaging.

• A. CT is more sensitive but is not the first-line investigation and involves higher radiation exposure in a young child.
• B. Flexible bronchoscopy is diagnostic but rigid bronchoscopy under general anaesthesia is used for removal; a chest X-ray is the appropriate initial step.
• D. Sputum culture is irrelevant to the acute presentation of a suspected foreign body aspiration.
• E. Peak flow measurement is unreliable and impractical in a 2-year-old and does not aid in localising a foreign body.

A raised immunoreactive trypsinogen on the newborn heel-prick screen is suggestive but not diagnostic of cystic fibrosis, and the sweat chloride test remains the gold-standard confirmatory investigation. A sweat chloride concentration greater than 60 mmol/L is diagnostic of cystic fibrosis, reflecting defective chloride transport across epithelial cells caused by CFTR gene mutations. Genetic testing for CFTR mutations can support the diagnosis but the sweat test is the definitive confirmatory step after a positive screen.

• A. Sputum culture is used to monitor infection in established disease, not to diagnose cystic fibrosis in a newborn.
• C. Nasal potential difference is a specialised research tool used in equivocal cases, not the standard confirmatory test.
• D. Faecal elastase assesses pancreatic exocrine function and is used to monitor pancreatic insufficiency, not to confirm the diagnosis.
• E. A chest X-ray may show changes in established cystic fibrosis lung disease but is not a diagnostic test in a newborn.

Innocent murmurs are typically soft (grade 1-2/6), systolic, vary with position or respiration, and occur in asymptomatic children with normal growth, pulses and no added sounds. A murmur that is loud (grade 4/6 or above), associated with a palpable thrill, diastolic, pansystolic, radiates widely, or is accompanied by symptoms (such as failure to thrive, cyanosis or weak femoral pulses) suggests structural heart disease and warrants echocardiography. The presence of a thrill indicates turbulent flow significant enough to be palpable, a hallmark of pathological murmurs.

• B. Positional variation (louder supine, softer sitting or standing) is typical of innocent murmurs, not a red flag.
• C. Murmurs confined to systole without radiation are typically benign findings.
• D. Normal growth and an asymptomatic child are reassuring features of an innocent murmur, not indications for referral.
• E. A soft grade 2/6 intensity is characteristic of an innocent murmur.

In a ventricular septal defect, blood shunts from the higher-pressure left ventricle to the lower-pressure right ventricle, but the degree of left-to-right shunting depends on the relative resistances of the systemic and pulmonary circulations. Pulmonary vascular resistance remains physiologically high for the first few weeks of life and then falls gradually, so symptoms such as heart failure, poor feeding and failure to thrive typically emerge over the following weeks as the shunt increases. This explains why many infants with VSDs are asymptomatic at birth but develop symptoms by 4-8 weeks of age.

• B. Ductal closure is unrelated to the pathophysiology of shunting across a ventricular septal defect.
• C. The foramen ovale is not the relevant mechanism in VSD physiology; the key determinant is pulmonary vascular resistance.
• D. Maternal antibodies have no protective role against volume overload in congenital heart disease.
• E. A VSD causes a left-to-right shunt due to the pressure gradient between the ventricles; a right-to-left shunt would cause cyanosis, which is absent here.

This is a hypercyanotic 'tet spell', precipitated by crying or exertion, in which infundibular spasm worsens right ventricular outflow obstruction, increasing right-to-left shunting and causing a quieter murmur due to reduced flow across the outflow tract. First-line management is to calm the child, position them in the knee-to-chest position (or squatting in older children), which increases systemic vascular resistance and reduces right-to-left shunting, and to give high-flow oxygen. If this fails, further measures include morphine, intravenous fluids, beta-blockers or phenylephrine to improve the spell.

• A. Intubation is reserved for spells refractory to initial measures and is not the first step in a conscious, breathing infant.
• B. Furosemide treats fluid overload, not the dynamic infundibular obstruction causing a tet spell.
• C. Bronchodilators treat airway obstruction from asthma or bronchospasm, not the cardiac outflow obstruction in a tet spell.
• E. Prostaglandin E1 maintains ductal patency in duct-dependent lesions diagnosed in the neonatal period, not acute tet spells in an older infant.

Mesenteric adenitis typically follows or accompanies an upper respiratory tract infection and presents with diffuse, often migratory abdominal pain, high fever relative to the degree of abdominal tenderness, and generalised lymphadenopathy. Abdominal examination shows soft, non-peritonitic findings without true guarding or rebound, unlike appendicitis. The preceding coryzal illness and palpable cervical nodes support a reactive mesenteric lymphadenitis rather than a surgical abdomen. It is a diagnosis of exclusion once appendicitis has been reasonably ruled out clinically or radiologically.

• A. Intussusception typically occurs in infants under 2 years with colicky pain, vomiting and redcurrant jelly stools.
• B. Meckel diverticulitis presents similarly to appendicitis with localised peritonism and is not linked to a preceding viral illness.
• D. Appendicitis typically causes localised right iliac fossa tenderness with guarding and rebound, not diffuse non-peritonitic tenderness.
• E. Pancreatitis causes epigastric pain radiating to the back with markedly raised serum amylase or lipase.

In children with suspected appendicitis where the clinical diagnosis is uncertain, ultrasound is the first-line imaging investigation because it avoids ionising radiation and can identify a thickened, non-compressible appendix, free fluid, or an alternative diagnosis such as ovarian pathology. CT is more sensitive but is generally reserved for equivocal ultrasound results or atypical presentations because of radiation exposure concerns in children. Plain X-ray has poor sensitivity and specificity for appendicitis. Laparoscopy is a diagnostic and therapeutic surgical step, not a preoperative investigation.

• A. Plain abdominal X-ray has low sensitivity for appendicitis and is not routinely used to confirm the diagnosis.
• C. Barium enema is not used in the diagnosis of acute appendicitis and risks perforation.
• D. CT involves significant radiation exposure in children and is used only if ultrasound is inconclusive.
• E. Diagnostic laparoscopy is an operative procedure, not a preliminary investigation before surgery.

The UK schedule gives PCV only at 12 weeks during the primary infant series (not at 8 weeks), alongside the second doses of 6-in-1 and rotavirus vaccines. The 6-in-1 and rotavirus vaccines are given at both 8 and 12 weeks as part of the primary course. MenB is given at 8, 16 weeks and 1 year, so it is also given at 8 weeks, unlike PCV. MenACWY is given later, in adolescence.

• A. MenB is given at 8 weeks as well as 12 and 16 weeks, so it is not unique to the 12-week visit.
• B. MenACWY is offered to teenagers and new university entrants, not in infancy.
• C. The 6-in-1 vaccine is given at both 8 and 12 weeks, so it does not distinguish the two visits.
• D. Rotavirus vaccine is given at both 8 and 12 weeks as part of its two-dose primary course.

Measles is a notifiable disease under the Health Protection (Notification) Regulations 2010, and clinicians must notify the proconsultant in health protection or UKHSA on clinical suspicion alone, without waiting for laboratory confirmation. The clinical picture here, with Koplik spots followed by a cephalocaudal maculopapular rash, is classic for measles. Prompt notification allows public health follow-up, contact tracing and outbreak control measures. Laboratory testing (oral fluid or serum IgM) should also be arranged, but this does not replace or delay notification.

• B. Post-exposure MMR vaccination may help susceptible contacts but is not a treatment for an already symptomatic case.
• C. Aciclovir is not indicated for measles, which is managed supportively.
• D. Notification must not be delayed for laboratory confirmation; it should be done on clinical suspicion.
• E. Ceftriaxone is an antibiotic and has no role in uncomplicated viral measles.

In a pregnant woman with a significant varicella exposure and uncertain immune status, the first step is to check varicella zoster IgG serology urgently, as up to 80-90% of adults in the UK are already immune and would not require any further intervention. If she is found to be non-immune, VZIG should be given as soon as possible (ideally within 10 days of exposure) because varicella in pregnancy carries risks of fetal varicella syndrome and severe maternal infection. The live varicella vaccine is contraindicated in pregnancy. Prophylactic aciclovir may be considered in some non-immune women instead of VZIG depending on timing, but serology must be checked first.

• B. Aciclovir may be used in some non-immune women but checking immunity status takes priority over starting treatment.
• C. VZIG should only be given after confirming non-immunity, not empirically before checking serology.
• D. Immune status must be confirmed first, as a significant exposure in a non-immune pregnant woman requires prophylaxis.
• E. Live attenuated varicella vaccine is contraindicated during pregnancy.

Parvovirus B19 infects erythroid progenitor cells, and in pregnancy transplacental infection can suppress fetal erythropoiesis, leading to severe fetal anaemia, high-output cardiac failure and non-immune hydrops fetalis. The risk is highest when infection occurs before 20 weeks' gestation. Affected pregnancies require referral for serial ultrasound monitoring for signs of hydrops and fetal anaemia, with consideration of intrauterine transfusion if severe. Congenital cataracts and deafness are associated with congenital rubella, hepatitis with congenital CMV or herpes, and intracranial calcification with congenital toxoplasmosis or CMV.

• A. Neonatal hepatitis is a recognised feature of congenital CMV or herpes infection, not parvovirus B19.
• B. Limb reduction defects are associated with congenital varicella syndrome, not parvovirus B19.
• C. Congenital cataracts and deafness are classically associated with congenital rubella syndrome, not parvovirus B19.
• E. Intracranial calcification is characteristic of congenital toxoplasmosis or CMV infection.

Scarlet fever is caused by an erythrogenic exotoxin-producing strain of group A Streptococcus (Streptococcus pyogenes) and classically presents with fever, strawberry tongue, and a sandpaper-textured rash with circumoral pallor. First-line treatment according to UK guidance is a 10-day course of oral phenoxymethylpenicillin (penicillin V), which reduces the duration of symptoms, transmission risk, and the risk of suppurative and non-suppurative complications such as rheumatic fever and glomerulonephritis. Children should be excluded from school until at least 24 hours after starting antibiotics. In penicillin allergy, a macrolide such as azithromycin or clarithromycin is used instead.

• A. Doxycycline is not used in children for scarlet fever and is generally avoided under 12 years due to dental staining.
• B. Antibiotics are indicated in scarlet fever to reduce complications and transmission, so supportive care alone is insufficient.
• C. Azithromycin is reserved for patients with penicillin allergy, not first-line treatment.
• D. Amoxicillin is not the first-line choice for scarlet fever and a shorter 5-day course is not the recommended duration.

Hand, foot and mouth disease is a self-limiting viral illness, most commonly caused by coxsackievirus A16, and does not require exclusion from school or nursery according to UK Health Security Agency guidance. Management is purely symptomatic, with advice on adequate fluid intake, paracetamol for fever or discomfort, and good hand hygiene to reduce the (low) risk of spreading infection, since the child can return as soon as they feel well enough to participate in normal activities. Formal exclusion periods apply to other infections such as scarlet fever or diarrhoeal illness, but not to hand, foot and mouth disease.

• A. The 48-hour post-fever exclusion rule applies to diarrhoeal and vomiting illnesses, not hand, foot and mouth disease.
• B. Stool testing for viral clearance is not part of standard management or exclusion guidance for this condition.
• C. A fixed 5-day exclusion period is not required for hand, foot and mouth disease.
• D. There is no requirement to wait for crusting; hand, foot and mouth disease does not require school exclusion at all.

In neonates and infants under 3 months, empirical treatment for bacterial meningitis is cefotaxime plus amoxicillin (or ampicillin), covering Group B streptococcus, E. coli, and Listeria monocytogenes. Ceftriaxone is avoided in neonates because it displaces bilirubin from albumin and can cause kernicterus, and it can precipitate with calcium-containing intravenous fluids commonly used in this age group. Dexamethasone is not recommended in neonates and is reserved for older children with suspected or confirmed bacterial meningitis beyond the neonatal period. Amoxicillin specifically covers Listeria, which ceftriaxone or cefotaxime alone would not reliably treat.

• A. Benzylpenicillin alone does not provide adequate Gram-negative cover needed for E. coli in this age group.
• B. Ceftriaxone is avoided in neonates due to the risk of kernicterus and calcium precipitation, and does not cover Listeria.
• D. Vancomycin and rifampicin are not first-line empirical therapy for neonatal bacterial meningitis.
• E. Ceftriaxone is unsuitable in neonates, and dexamethasone is not recommended at this age.

The NICE traffic light system (NG143) classifies a respiratory rate above 50 breaths/min in a child aged 6-12 months, or nasal flaring, as amber features, indicating intermediate risk requiring further clinical assessment, a specific safety net, or follow-up arrangement rather than immediate emergency referral. Green features (normal colour, responding normally, no amber or red features) are reassuring but this child has amber features present. Red features such as reduced consciousness, mottled or ashen skin, grunting, or capillary refill time of 3 seconds or more would mandate urgent referral, which is not present here. The correct approach is structured amber-pathway management, such as a face-to-face review or clear parental safety-netting advice with a follow-up plan.

• A. Amber features still require a follow-up plan, not simple discharge.
• B. There is no indication for admission or antibiotics without further assessment in an amber-risk child.
• D. Green classification would be incorrect as he has amber features (tachypnoea, nasal flaring).
• E. Red features (e.g. grunting, mottled skin, CRT ≥3 seconds, reduced consciousness) are absent, so emergency referral is not required.

A simple febrile convulsion is generalised, lasts under 15 minutes, does not recur within 24 hours, and is followed by full recovery within an hour, all of which match this presentation. Management is reassurance and safety-netting: advise parents on antipyretic use for comfort (not seizure prevention), how to position the child safely during a seizure, and to call an ambulance if a seizure lasts longer than 5 minutes. Complex febrile convulsions involve focal features, duration over 15 minutes, or recurrence within 24 hours, none of which are present here. Routine investigations such as CT or lumbar puncture are not indicated for a straightforward simple febrile convulsion with a clear source of fever and normal examination.

• A. There is a clear febrile trigger and typical features of a febrile convulsion, not an afebrile epileptic seizure, and valproate is not indicated.
• B. Prophylactic antiepileptic medication is not recommended for simple febrile convulsions.
• C. This is a simple, not complex, febrile convulsion, and lumbar puncture is not routinely required.
• D. This does not meet criteria for a complex febrile convulsion (focal features, duration >15 minutes, or recurrence within 24 hours), and CT is not routinely indicated.

This presentation (clusters of flexor spasms, developmental regression, onset in infancy) is characteristic of infantile spasms (West syndrome), and the key diagnostic test is an EEG, which classically shows hypsarrhythmia, a chaotic pattern of high-amplitude slow waves with multifocal spikes. Confirming this pattern guides urgent treatment with vigabatrin or corticosteroids (prednisolone or tetracosactide), as early treatment improves developmental outcome. MRI brain may be performed to look for an underlying structural cause but does not establish the diagnosis, which is EEG-based. Metabolic screening and lumbar puncture may be considered in the work-up for an underlying cause but are not the primary diagnostic test for this syndrome.

• A. MRI may identify an underlying structural cause but does not establish the diagnosis of infantile spasms.
• C. Visual evoked potentials are not used to diagnose infantile spasms.
• D. Metabolic screening may be part of the aetiological work-up but is not the key diagnostic test for this syndrome.
• E. Lumbar puncture is not the diagnostic test for infantile spasms.

Prematurity with intraventricular haemorrhage is a major risk factor for cerebral palsy, and the findings described (delayed sitting, persistent fisting of the hands, scissoring of the legs suggesting lower limb spasticity) are early motor warning signs that should prompt referral for specialist neurodevelopmental assessment and physiotherapy input. Cerebral palsy is a clinical diagnosis based on evolving motor signs and history, and early referral allows prompt multidisciplinary input (physiotherapy, occupational therapy) which improves functional outcomes. These signs are outside normal developmental limits even accounting for corrected age, so reassurance and simple review would delay necessary assessment and intervention. Genetic testing for muscular dystrophy and nerve conduction studies are not indicated, as the clinical picture (spasticity, scissoring, history of IVH) points to a central, not peripheral or myopathic, cause.

• A. These findings are abnormal even for her corrected age and warrant assessment, not reassurance alone.
• B. The clinical picture and risk factors point to a central cause from IVH and prematurity, not a muscular dystrophy.
• C. The signs described (spasticity, scissoring) suggest an upper motor neurone/central cause, not a peripheral neuropathy.
• D. Physiotherapy alone without specialist neurodevelopmental referral would miss the need for formal diagnosis and multidisciplinary planning.

Wilms tumour (nephroblastoma) classically presents as a painless, smooth, unilateral flank mass confined to one side of the abdomen, often with hypertension (from renin secretion) and microscopic haematuria, in a child around 2-5 years old. Neuroblastoma, by contrast, typically arises from sympathetic chain tissue and presents as an irregular mass that often crosses the midline, with systemic features such as bone pain, periorbital bruising ('raccoon eyes') or proptosis from metastases, and raised urinary catecholamine metabolites. The smooth contour, lack of midline crossing, hypertension and haematuria in this child all favour Wilms tumour over neuroblastoma. Hepatoblastoma presents as a right upper quadrant mass arising from the liver rather than the flank. Mesoblastic nephroma is a renal tumour of infancy, typically presenting before 3 months of age.

• A. Usually presents with a mass related to muscle, genitourinary or head and neck sites, not a flank renal mass with haematuria.
• C. Typically presents in infants under 3 months old, not a 2-year-old.
• D. Arises from the liver causing a right upper quadrant mass, not a flank mass with haematuria.
• E. Neuroblastoma masses are typically irregular and cross the midline, often with systemic catecholamine-related features not seen here.

Leukocoria (a white pupillary reflex replacing the normal red reflex) in an infant or young child is a red-flag sign for retinoblastoma until proven otherwise, and NICE guidance mandates an urgent (within 2 weeks) referral to ophthalmology for suspected cases. Early referral allows prompt examination under anaesthesia and imaging to confirm the diagnosis, as retinoblastoma is sight- and life-threatening but highly curable when treated early. There is no infective sign (redness, discharge) to suggest conjunctivitis, so antibiotics are not indicated. A normal variant diagnosis without specialist examination risks a dangerous delay. Imaging is arranged by the specialist team after referral, not before, and should not delay referral.

• A. The suspicion of retinoblastoma warrants an urgent, not routine, referral pathway.
• B. There are no features of infection (redness, discharge, pain) to justify antibiotic treatment.
• D. Imaging should be arranged by the specialist team after urgent referral, not used to delay it.
• E. Leukocoria is never a normal finding and must not be dismissed without specialist assessment.

This presentation, an overweight adolescent boy with groin and referred knee pain, a limp, and restricted internal rotation with the leg held in external rotation, is classic for slipped upper femoral epiphysis (SUFE), which typically occurs in boys aged 10-15 years, especially those with obesity. The first-line investigation is a plain X-ray of the pelvis including both anteroposterior and frog-leg lateral views, which show posterior and inferior displacement of the femoral epiphysis relative to the metaphysis (widening and lucency of the growth plate, or a line along the superior femoral neck that no longer intersects the epiphysis, known as Trethowan's sign). Both hips are imaged because bilateral involvement is common. Ultrasound is useful for detecting a joint effusion in younger children with suspected transient synovitis or septic arthritis but does not show the epiphyseal slip. MRI, CT and bone scan may be used in equivocal cases but are not first-line.

• A. Ultrasound detects joint effusions but does not demonstrate the epiphyseal displacement characteristic of SUFE.
• B. CT is not first-line and involves higher radiation exposure than plain X-ray.
• C. There are no features suggesting a spinal cause for his hip pain and limp.
• D. Bone scan may help in equivocal cases but is not the first-line investigation for suspected SUFE.

This boy's presentation, a 4-10 year-old with an insidious limp and hip/groin pain without fever, is typical of Perthes disease, which results from idiopathic avascular necrosis of the femoral head epiphysis. Early X-ray changes include increased density (sclerosis) and flattening of the femoral head epiphysis, progressing over time to fragmentation and later remodelling; a 'frog-leg' lateral view can increase sensitivity for early changes. Widening of the growth plate with posterior displacement describes slipped upper femoral epiphysis, which occurs in older, often overweight adolescents. A lytic lesion with sunburst periosteal reaction suggests osteosarcoma, and periosteal reaction with soft tissue swelling of the diaphysis would raise concern for a bone infection or tumour such as Ewing sarcoma. Joint space narrowing with erosions suggests an inflammatory or septic arthropathy rather than Perthes disease.

• A. A sunburst periosteal reaction is characteristic of osteosarcoma, not Perthes disease.
• B. This pattern raises concern for infection or a bone tumour such as Ewing sarcoma, not Perthes disease.
• C. This describes the epiphyseal slip seen in slipped upper femoral epiphysis, typically in older overweight adolescents.
• E. Joint space narrowing with erosions suggests septic or inflammatory arthritis rather than avascular necrosis.

A spiral fracture of the humerus in a pre-mobile infant, bruises of varying ages in non-bony sites such as the buttocks and back, and an inconsistent or changing history from the carer are all strong indicators of non-accidental injury. Spiral fractures result from a twisting force and are rarely caused by simple falls, and an infant who is not yet crawling or pulling to stand has very limited capacity to sustain accidental injury from a fall off furniture. The appropriate next step is admission for safety and urgent referral to the paediatric safeguarding team, who will coordinate a full assessment including skeletal survey, child protection medical examination and liaison with social services, following GMC and RCPCH safeguarding guidance. Delaying action through outpatient follow-up, routine health visitor review, or discharge home risks the child's ongoing safety.

• A. Safeguarding concerns of this severity require urgent same-day escalation, not deferral to a routine health visitor review.
• C. Treating only the fracture and discharging home ignores the safeguarding concern and risks further harm.
• D. Discharging home risks ongoing harm; the injury pattern and history mismatch require same-day safeguarding action.
• E. Delaying assessment by 2 weeks leaves the child at risk; urgent same-day referral is required.