Paediatrics

Biliary atresia is progressive obliteration of the extrahepatic bile ducts causing neonatal cholestasis; persistent jaundice with pale stools or dark urine needs prompt split bilirubin testing and urgent specialist referral because early surgery offers the best chance of preserving the native liver.

An acute viral small-airway infection in babies and young children causing coryza, cough, tachypnoea, wheeze or crackles and feeding difficulty; treatment is supportive, with escalation driven by work of breathing, hydration, apnoea and oxygenation.

Cerebral palsy is a permanent disorder of movement and posture attributed to a non-progressive disturbance in the developing brain; the neurological lesion is static, but tone-related musculoskeletal problems and associated impairments require proactive, lifelong multidisciplinary care.

Cow's milk protein allergy is an immune-mediated reaction to milk proteins in infancy, either immediate and IgE-mediated or delayed and non-IgE-mediated; diagnosis depends on an allergy-focused history and, for non-IgE disease, a supported elimination and reintroduction plan.

A usually viral upper-airway infection causing subglottic swelling and a barking cough, hoarse voice and inspiratory stridor; keep the child calm, give steroid treatment when indicated, and treat stridor at rest or deterioration as an airway emergency.

Cryptorchidism is failure of one or both testes to lie in the scrotum; persistent extrascrotal testes carry fertility, malignancy and torsion risks, so current NHS screening requires timely examination, referral and specialist orchidopexy planning.

Developmental milestones are approximate age-linked skills across several domains; the clinically important task is to assess the child's trajectory, pattern and examination, then act promptly on regression, sustained developmental arrest or guideline-defined referral thresholds.

Faltering growth is a concerning change in a child's growth trajectory, usually weight first; the commonest mechanism is inadequate intake, so accurate serial measurements, feeding observation and whole-child assessment come before indiscriminate investigations.

A seizure occurring with fever in a young child without evidence of CNS infection or another acute cause; most are brief and self-limiting, but the priority is seizure safety, assessment of the febrile illness and recognition of meningitis, prolonged, focal or recurrent seizures.

IgA immune-complex small-vessel vasculitis causes palpable purpura with variable joint, gastrointestinal and renal disease; the visible rash usually settles, but renal surveillance determines long-term safety.

A segment of bowel telescopes into the adjacent segment, dragging its mesentery with it and causing intermittent obstruction, venous congestion, ischaemia and potentially perforation; prompt paediatric-surgical assessment is essential.

An acute systemic medium-vessel vasculitis in childhood with persistent fever and mucocutaneous features; it is a time-critical diagnosis because coronary artery inflammation can lead to aneurysm, thrombosis and myocardial ischaemia.

Mesenteric adenitis is reactive inflammation of mesenteric lymph nodes, often after a viral illness, causing abdominal pain that can mimic appendicitis; it is a diagnosis reached after safe clinical exclusion and observation rather than by enlarged nodes alone.

Mumps is an acute mumps-virus infection classically causing painful parotid swelling; it remains vaccine-preventable and notifiable in England, and complications such as meningitis, orchitis, pancreatitis or hearing loss need active assessment.

Necrotising enterocolitis (NEC) is acquired ischaemic and inflammatory necrosis of the immature neonatal bowel, in which bacterial gas tracks into the bowel wall and portal veins and necrosis perforates.

Jaundice is common in newborns, but its timing, bilirubin fraction, rate of rise and effect on the baby distinguish physiological jaundice from haemolysis, sepsis, cholestatic liver disease and bilirubin neurotoxicity.

Suspected inflicted injury is a safeguarding and clinical emergency when the injury, account, timing or developmental stage do not fit; act on serious concern without waiting to prove abuse.

Progressive hypertrophy of the pyloric muscle causes gastric-outlet obstruction in a young infant, producing worsening non-bilious vomiting and dehydration; fluid and electrolyte correction must precede pyloromyotomy.

Fever is a common, non-specific response that ranges from self-limiting viral illness to life-threatening sepsis; structured assessment of airway, breathing, circulation, behaviour, hydration, age and source of infection determines urgency.

Pertussis is a highly contagious Bordetella pertussis infection causing prolonged paroxysmal cough; young infants may present with apnoea or cyanosis rather than a whoop and are at greatest risk of severe disease.