Paeds DDx

Question 1

The tiny baby

Answer 1

1 Normal, constitutionally small baby.
2 Preterm delivery.
3 Intrauterine growth restriction.
4 Genetic syndrome

Question 2

The sick preterm baby

Answer 2

1 Septicaemia.
2 Meningitis.
3 Pneumonia.
4 Necrotizing enterocolitis.
5 Intraventricular haemorrhage.
6 Apnoea of prematurity.
7 Respiratory distress syndrome.
8 Patent ductus arteriosus.

Question 3

The baby with breathing difficulties

Answer 3

1 Transient tachypnoea of the newborn.
2 Meconium or milk aspiration.
3 Respiratory distress syndrome.
4 Congenital pneumonia.
5 Birth asphyxia.
6 Diaphragmatic hernia.
7 Tracheo-oesophageal fi stula.
8 Septicaemia.
9 Laryngomalacia.

Question 4

The blue baby

Answer 4

1 Respiratory causes:
• Congenital respiratory disorder.
• Acquired respiratory problem.
• Congenital obstruction.
• Acquired obstruction.
2 Congenital cyanotic heart disease:
• Tetralogy of Fallot.
• Transposition of the great arteries.
• Other rarer cyanotic defects.
3 Lack of respiratory drive:
• Seizure disorder.
• Congenital CNS malformation.
• CNS infection.
• Drugs.

Question 5

The jaundiced baby

Answer 5

1 Physiological jaundice.
2 Breast milk jaundice.
3 Hepatitis.
4 Biliary atresia or other obstructive cause.
5 Antibody-mediated haemolytic disorders (rhesus,
ABO incompatibility).
6 Red cell instability disorders (e.g. pyruvate kinase deficiency, spherocytosis, glucose-6 phosphate dehydrogenase
(G6PD) deficiency).
7 Infection (e.g. urinary tract infection).
8 Congenital hypothyroidism.
9 Metabolic disorders (e.g. galactosaemia, α1-antitrypsin
deficiency, Crigler–Najjar syndrome).

Question 6

Is my baby alright?

Answer 6

1 Female virilization:
• Congential adrenal hyperplasia – excessive
testosterone.
• Maternal androgen ingestion.
2 Male inadequate virilization:
• Cryptorchidism.
• Congential adrenal hyperplasia – testosterone
defi ciency.
• Androgen insensitivity.
3 True hermaphroditism.

Question 7

The febrile infant

Answer 7

1 Serious bacterial infection, e.g. meningitis,
septicaemia.
2 Localized infection, e.g. otitis media, pneumonia, UTI,
gastroenteritis, osteomyelitis.
3 Viral infection: self-limiting URTI or specifi c infection
(e.g. chickenpox)
4 Other systemic infection, e.g. malaria.
5 Infl ammatory disorders, e.g. infl ammatory bowel
disease.
6 Autoimmune disorders, e.g. juvenile idiopathic
arthritis.
7 Malignancy.
8 Kawasaki’s disease.

Question 8

The vomiting baby

Answer 8

1 Pyloric stenosis.
2 Gastro-oesophageal refl ux.
3 Posseting.
4 Gastroenteritis.
5 Bowel obstruction.
6 Respiratory tract infection.
7 UTI or other systemic infection.

Question 9

The lethargic baby

Answer 9

1 Meningitis.
2 Encephalitis.
3 Other focal bacterial infection, e.g. pneumonia, UTI,
otitis media.
4 Viral infection.

Question 10

The thin infant

Organic causes

Answer 10

1 Inability to get feed into the intestine (e.g. cleft palate
or coordination problems in cerebral palsy).
2 Gut malfunction – severe gastro-oesophageal refl ux.
3 Malabsorption (e.g. cystic fi brosis, coeliac disease).
4 Energy wastage in chronic disease (e.g. congenital
heart disease, renal failure, cystic fi brosis).
5 Problems with control of growth (e.g. hypothyroidism,
congenital adrenal hyperplasia, syndromes).

Question 11

The thin infant

Non-organic causes

Answer 11

The lack of intake could be due to:
• Poor breastfeeding technique.
• Inappropriate or inadequate diet.
• Poor meal time environment, e.g. hurried meals, distractions,
force feeding.
• Child abuse.
Other possibilities are erroneous: such as a mischarted
weight, or a small but normal child.

Question 12

The odd-looking baby

Answer 12

1 Trisomy 13, 18 or 21.
2 Sex chromosome disorder.
3 Intersex conditions.
4 Chromosome deletion or microdeletion syndrome.
5 Fragile X syndrome.
6 Teratogenic cause (e.g. fetal alcohol syndrome).
7 Intrauterine disruption.
8 Other fetal developmental disorder.

Question 13

Ralph’s lumpy groin

Answer 13

1 Hydrocoele.
2 Hernia.
3 Lymphadenopathy.
4 Haematocoele.
5 Tumour.

Question 14

The noisy breather

Answer 14

1 Croup.
2 Tracheitis.
3 Epiglottitis.
4 Asthma with infection.
5 Pneumonia (bronchopneumonia or lobar
pneumonia).

Question 15

The disruptive little boy

Answer 15

1 Hyperactivity disorder.
2 Abuse or neglect.
3 Hearing impairment.
4 Autistic spectrum disorder.
5 Intellectual impairment.
6 Bullying or similar specifi c reason for unhappiness.
7 Normal toddler.

Question 16

The grumpy toddler

Answer 16

1 Psychosocial or behavioural problem.
2 Inappropriate diet.
3 Coeliac disease.
4 Cystic fibrosis.
5 Cow’s milk protein intolerance.
6 Specific carrier protein defects.
7 Bile salt deficiency.
8 Obstructive sleep apnoea.

Question 17

The boy with fits

Answer 17

1 Epilepsy.
2 CNS infection.
3 Febrile convulsions. 
4 Metabolic causes – hypoglycaemia, hypocalcaemia,
hypo- and hypernatraemia or hypomagnesaemia.
5 Cerebral hypoxia.
6 Head trauma/non-accidental injury.
7 Toxins/poisoning.

Question 18

The colicky infant

Answer 18

1 Simple colic.
2 Gastroenteritis.
3 Intussusception.
4 Strangulated hernia.
5 Appendicitis.
6 Abdominal migraine.
7 Other surgical causes.

Question 19

The slow walker

Answer 19

1 Constitutional delay.
2 Global delay.
3 Motor cortex problem (e.g. cerebral palsy).
4 Neuromuscular disorder.
5 Deprivation.

Question 20

The toddler with diarrhea

Answer 20

1 Non-specific toddler diarrhoea.
2 Infective causes – gastroenteritis or infection of other
system.
3 Post-gastroenteritis syndrome.
4 Malabsorption – coeliac disease, cystic fi brosis, cow’s
milk protein intolerance.
5 Inflammatory bowel disease.

Question 21

The swollen child

Answer 21

1 Anaphylaxis.
2 Cellulitis – orbital, periorbital.
3 Angioedema.
4 Nephrotic syndrome.
5 Other causes of hypoalbuminaemia (i.e. other than nephrotic syndrome).

Question 22

Yet another chest infection

Answer 22

1 Normal, bad luck.
2 Asthma.
3 Cystic fibrosis.
4 Immunoglobulin abnormality.
5 Other immune deficiency.
6 Tuberculosis.
7 Primary ciliary dyskinesia, e.g. Kartagener’s
syndrome.

Question 23

The drowsy child

Answer 23

1 Meningitis Å} septicaemic shock.
2 Respiratory cause (e.g. asthma).
3 Metabolic cause (e.g. diabetic ketoacidosis).
4 Sickle cell crisis.
5 Trauma leading to raised intracranial pressure.
6 Poisoning.

Question 24

The breathless child

Answer 24

1 Acute asthma.
2 Inhaled foreign body.
3 Epiglottitis.
4 Croup.
5 Anaphylaxis.
6 Trauma (e.g. chemical ingestion/inhalation).

Question 25

A sore throat

Answer 25

1 Normal childhood viral infections.
2 Common childhood bacterial infections.
3 Allergy.
4 Immune deficiency due to steroid use.
5 Immune deficiency condition.
6 Bone marrow disorder.
7 Psychosocial issues.

Question 26

The short child

Answer 26

1 Familial short stature.
2 Endocrine problem (e.g. growth hormone deficiency
or hypothyroidism).
3 Nutritional/malabsorptive problem.
4 Steroid excess (endogenous or exogenous).
5 Syndrome (e.g. Turner’s syndrome).

Question 27

Swollen knees and a rash

Answer 27

1 Meningococcal disease.
2 Henoch–Schönlein purpura.
3 Juvenile idiopathic arthritis.
4 Idiopathic thrombocytopenic purpura.
5 Septic arthritis.
6 Osteomyelitis.

Question 28

The asthmatic teenager

Answer 28

1 Increasing severity of asthma.
2 Exposure to new or increased allergens.
3 Exposure to other trigger factor (e.g. infection,
exercise).
4 Poor compliance with medication.
5 Incorrect inhaler technique.
6 Mild cystic fibrosis.
7 Immunodeficiency.

Question 29

The limping boy

Answer 29

1 Trauma (soft tissue injury or fracture).
2 Transient synovitis.
3 Arthritis (infective or juvenile idiopathic arthritis)
4 Slipped femoral epiphysis.
5 Osgood–Schlatter disease.
6 Avascular necrosis of the femoral head.
7 Malignancy.

Question 30

A nasty chest infection

Answer 30

1 Asthma.
2 Tuberculosis.
3 Cystic fibrosis.
4 Immune deficiency.

Question 31

A bruised toddler

Answer 31

1 Non-accidental injury/neglect.
2 Bleeding disorder.
3 Brittle bones.
4 Copper defi ciency.
5 Rickets.

Question 32

The teenager who has taken

an overdose

Answer 32

1 Depression.
2 Bullying.
3 Child abuse.
4 Anorexia nevosa or other eating disorder.
5 Cry for help/attention.
6 Drug misuse.

Question 33

Cough

Answer 33

1 Asthma.
2 Upper respiratory tract infection (viral or bacterial).
3 Lower respiratory tract infection (viral or bacterial).
4 Habit cough.
5 Suppurative lung disease.
6 Inhaled foreign body.