# PLAB 1 Paediatrics Questions: 10 Free Practice MCQs

> 10 free PLAB 1 paediatrics questions with answers and explanations, from a bank of 174 paediatrics questions. Try them now, no sign up.

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Last updated: 2026-10-29

Ten PLAB 1-style paediatrics questions with the answer and the reasoning behind it. They come from the UK.med bank, which has 174 paediatrics questions and many more across every topic.

1. 1 / 10  
A 4-year-old boy is brought to the clinic by his parents. They report that he does not make eye contact, does not respond to his name, and has not developed spoken language. He plays repetitively by lining up his toy cars and becomes extremely distressed if his routine is altered.  
What is the most likely diagnosis?  
Show answer

**Answer: A.** Autism Spectrum Disorder (ASD)

**Why:** Autism Spectrum Disorder (ASD) is characterized by persistent deficits in social communication and social interaction across multiple contexts, alongside restricted, repetitive patterns of behavior, interests, or activities. NICE guidelines emphasize early recognition of these signs and referral to a multidisciplinary child development team for formal assessment.

  * **B.** ADHD is characterized by hyperactivity, impulsivity, and inattention, rather than core deficits in social communication and repetitive routine behaviors.
  * **C.** This affects motor coordination (dyspraxia) and does not present with severe speech delay or repetitive play patterns.
  * **D.** While he has speech delay, the specific presence of repetitive play and insistence on routine point specifically to ASD rather than isolated global delay.  
Sources: NICE NG128
2. 2 / 10  
A 13-year-old has severe pyelonephritis and cefalexin is selected. The treating team considers age, clinical severity, ability to take oral treatment and prior microbiology.  
Which dose escalation is listed?  
Show answer

**Answer: B.** Up to 1 to 1.5 g three or four times daily

**Why:** For severe infection at ages 12 to 15 years, NICE lists cefalexin up to 1 to 1.5 g three or four times daily, for 7 to 10 days. Use age, size, severity and current culture information to apply the recommendation to the individual child.

  * **A.** 125 mg once daily is not the recommended action for which dose escalation is listed?. NICE NG111 recommends Up to 1 to 1.5 g three or four times daily instead. For severe infection at ages 12 to 15 years, NICE lists cefalexin up to 1 to 1.5 g three or four times daily, for 7 to 10 days. Use age, size, severity and current culture information to apply the recommendation to the individual child.
  * **C.** 12.5 mg/kg once daily is not the recommended action for which dose escalation is listed?. NICE NG111 recommends Up to 1 to 1.5 g three or four times daily instead. For severe infection at ages 12 to 15 years, NICE lists cefalexin up to 1 to 1.5 g three or four times daily, for 7 to 10 days. Use age, size, severity and current culture information to apply the recommendation to the individual child.
  * **D.** Single dose is not the recommended action for which dose escalation is listed?. NICE NG111 recommends Up to 1 to 1.5 g three or four times daily instead. For severe infection at ages 12 to 15 years, NICE lists cefalexin up to 1 to 1.5 g three or four times daily, for 7 to 10 days. Use age, size, severity and current culture information to apply the recommendation to the individual child.  
Sources: NICE NG111 recommendation 1.3.3 table 3
3. 3 / 10  
An asymptomatic 6-year-old has a continuous 'machinery' murmur heard at the upper left sternal edge.  
What is the likely diagnosis?  
Show answer

**Answer: A.** Patent Ductus Arteriosus

**Why:** Patent Ductus Arteriosus (PDA) causes a continuous 'machinery' murmur best heard at the left infraclavicular area because blood flows continuously from the higher-pressure aorta into the lower-pressure pulmonary artery during both systole and diastole. Ventricular septal defects produce a pan-systolic murmur, atrial septal defects cause a fixed split second heart sound, and innocent murmurs vary with posture.

  * **B.** Pan-systolic murmur.
  * **C.** Fixed split S2, ejection systolic murmur.
  * **D.** Usually systolic and changing with position.  
Sources: Oxford Handbook of Paediatrics
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5. 4 / 10  
A 6-year-old girl with a history of asthma is admitted with an acute severe asthma attack. She is speaking in single words, has a respiratory rate of 35 breaths/min, and oxygen saturation is 90% on room air. The team initiates treatment.  
What is the recommended initial drug therapy and dose of oral Prednisolone?  
Show answer

**Answer: C.** High-flow oxygen, nebulised Salbutamol (5mg) and Ipratropium bromide (250mcg), and oral Prednisolone 30mg

**Why:** BTS/SIGN guidelines for pediatric asthma attacks outline severity. Severe asthma in children: oxygen saturation < 92%, PEF < 50%, RR > 30 (age > 5) or > 40 (age 2-5), HR > 125 (age > 5) or > 140 (age 2-5), or unable to complete sentences. First-line therapy: oxygen to target 94-98%, nebulised Salbutamol 5mg + Ipratropium 250mcg, and oral Prednisolone (20mg for < 5 years, 30-40mg for >= 5 years) for 3-5 days.

  * **A.** Spacer is used for mild/moderate asthma. This child has severe asthma (sats 90%, unable to speak in sentences) requiring nebulised bronchodilators. A 10mg steroid dose is too low.
  * **B.** Oral or IV steroids must never be withheld in severe asthma. IV magnesium is a second-line therapy for life-threatening or refractory cases, not first-line.
  * **D.** Budesonide (inhaled steroid) and Montelukast (LTRA) are maintenance controller medications and have no role in hyperacute bronchodilatation for severe attacks.  
Sources: BTS/SIGN British Guideline on the Management of Asthma
6. 5 / 10  
A 5-year-old with UTI has poor urine flow and an abdominal mass. Urine findings are reviewed alongside the child's age, symptoms, response to treatment and previous UTI history.  
What is the appropriate interpretation?  
Show answer

**Answer: B.** Atypical UTI features

**Why:** Poor urine flow and an abdominal or bladder mass are atypical UTI features. Apply this recommendation using the child's age, symptoms, treatment response and previous UTI history; those details determine which NG224 pathway applies.

  * **A.** NICE NG224 recommendation 1.3.2 box 1 supports "Atypical UTI features". "Typical uncomplicated cystitis" does not follow the recommended approach for this presentation.
  * **C.** NICE NG224 recommendation 1.3.2 box 1 supports "Atypical UTI features". "Recurrent UTI by definition" does not follow the recommended approach for this presentation.
  * **D.** NICE NG224 recommendation 1.3.2 box 1 supports "Atypical UTI features". "Relevant only if nitrite positive" does not follow the recommended approach for this presentation.  
Sources: NICE NG224 recommendation 1.3.2 box 1
7. 6 / 10  
A 4-year-old girl is seen by her GP at home. She is lethargic, pyrexial (39.2°C), and has a non-blanching petechial rash on her torso and legs. The GP suspects meningococcal septicaemia and arranges an immediate blue-light ambulance transfer to the hospital.  
What immediate pharmacological action must the GP take before the ambulance arrives?  
Show answer

**Answer: D.** Administer intramuscular or intravenous Benzylpenicillin (1.2g) immediately

**Why:** NICE guideline NG203 recommends that for children with suspected meningococcal disease in the pre-hospital setting, a single dose of IM/IV Benzylpenicillin should be given as soon as possible, provided it does not delay transfer. Dose: <1 year: 300mg; 1-9 years: 600mg; >=10 years: 1.2g. Note: if the patient has a penicillin allergy, the dose should be withheld unless the allergy is mild and no cephalosporin is available. In-hospital treatment is with IV Ceftriaxone.

  * **A.** Meningococcal septicaemia can progress to death within hours. Delaying antibiotics for transfer is a major risk; pre-hospital benzylpenicillin is a life-saving intervention.
  * **B.** Oral antibiotics are ineffective and dangerous in a systemically shocked child; parenteral therapy is required.
  * **C.** Lumbar puncture is strictly contraindicated in the pre-hospital setting, and in the presence of signs of septicaemia or raised ICP (shock, purpuric rash) in the hospital.  
Sources: NICE NG203
8. 7 / 10  
A 2-year-old with UTI has not responded to suitable antibiotics within 48 hours. Urine findings are reviewed alongside the child's age, symptoms, response to treatment and previous UTI history.  
How is this classified?  
Show answer

**Answer: B.** Atypical UTI

**Why:** Failure to respond to suitable antibiotics within 48 hours is an atypical UTI feature, but does not by itself define recurrence. Apply this recommendation using the child's age, symptoms, treatment response and previous UTI history; those details determine which NG224 pathway applies.

  * **A.** NICE NG224 recommendation 1.3.2 box 1 supports "Atypical UTI". "Typical UTI" does not follow the recommended approach for this presentation.
  * **C.** NICE NG224 recommendation 1.3.2 box 1 supports "Atypical UTI". "Recurrent UTI by definition" does not follow the recommended approach for this presentation.
  * **D.** NICE NG224 recommendation 1.3.2 box 1 supports "Atypical UTI". "Not UTI unless imaging is abnormal" does not follow the recommended approach for this presentation.  
Sources: NICE NG224 recommendation 1.3.2 box 1
9. 8 / 10  
A 2-year-old has suspected UTI, both dipstick markers negative and no criterion for culture. Urine findings are reviewed alongside the child's age, symptoms, response to treatment and previous UTI history.  
What is the immediate approach?  
Show answer

**Answer: C.** Do not give antibiotics or send culture

**Why:** For age 3 months to under 3 years, if both leukocyte esterase and nitrite are negative, do not give antibiotics or send urine for microscopy and culture unless a specified culture criterion applies. Apply this recommendation using the child's age, symptoms, treatment response and previous UTI history; those details determine which NG224 pathway applies.

  * **A.** NICE NG224 recommendation 1.1.19 supports "Do not give antibiotics or send culture". "Give antibiotics and culture" does not follow the recommended approach for this presentation.
  * **B.** NICE NG224 recommendation 1.1.19 supports "Do not give antibiotics or send culture". "Culture but do not treat" does not follow the recommended approach for this presentation.
  * **D.** NICE NG224 recommendation 1.1.19 supports "Do not give antibiotics or send culture". "Repeat dipstick hourly" does not follow the recommended approach for this presentation.  
Sources: NICE NG224 recommendation 1.1.19
10. 9 / 10  
A 4-year-old girl is brought to the GP surgery. Her mother reports she suddenly developed a rash of small red spots on her chest and legs this morning. She had a mild viral URI 2 weeks ago. On examination, she is alert and active. She has diffuse petechiae and purpura, but no mucosal bleeding, hepatosplenomegaly, or lymphadenopathy. FBC shows: Hb 125 g/L, WBC 6.5 x 10^9/L, and platelets 12 x 10^9/L (low).  
What is the most likely diagnosis, and what is the recommended management for this presentation?  
Show answer

**Answer: D.** Immune Thrombocytopenia (ITP); watchful waiting and parental education on avoiding trauma

**Why:** Immune Thrombocytopenia (ITP) in children is usually an acute, self-limiting condition (resolves within 6 months in 80% of cases) triggered by viral infections. Management is guided by symptoms: (1) Cutaneous signs only (petechiae/bruising): observation regardless of platelet count. (2) Significant mucosal bleeding (epistaxis, GI bleed): IVIG (1g/kg) or oral Prednisolone. Platelet transfusions are reserved for life-threatening bleeding.

  * **A.** ALL presents with systemic signs: bone pain, fever, lymphadenopathy, hepatosplenomegaly, and pancytopenia (anaemia and neutropenia alongside thrombocytopenia). This child has isolated thrombocytopenia and is clinically well.
  * **B.** While meningococcal disease causes a petechial rash, the child is well, active, afebrile, and has normal hemodynamics, which rules out acute septicaemia.
  * **C.** Platelet transfusions and active treatments (corticosteroids, IVIG) are only indicated for severe, life-threatening mucosal bleeding, not for isolated cutaneous signs, as they do not change long-term remission rates.  
Sources: UK Guidelines on the Management of ITP in Children and Adults; NICE CKS
11. 10 / 10  
An 8-year-old with pyelonephritis is suitable for oral treatment. The treating team considers age, clinical severity, ability to take oral treatment and prior microbiology.  
Which cefalexin regimen is listed?  
Show answer

**Answer: D.** 12.5 mg/kg twice daily or 250 mg three times daily

**Why:** For ages 5 to 11 years, NICE lists cefalexin 12.5 mg/kg twice daily or 250 mg three times daily for 7 to 10 days. Use age, size, severity and current culture information to apply the recommendation to the individual child.

  * **A.** 125 mg once daily is not the recommended action for which cefalexin regimen is listed?. NICE NG111 recommends 12.5 mg/kg twice daily or 250 mg three times daily instead. For ages 5 to 11 years, NICE lists cefalexin 12.5 mg/kg twice daily or 250 mg three times daily for 7 to 10 days. Use age, size, severity and current culture information to apply the recommendation to the individual child.
  * **B.** 500 mg once daily is not the recommended action for which cefalexin regimen is listed?. NICE NG111 recommends 12.5 mg/kg twice daily or 250 mg three times daily instead. For ages 5 to 11 years, NICE lists cefalexin 12.5 mg/kg twice daily or 250 mg three times daily for 7 to 10 days. Use age, size, severity and current culture information to apply the recommendation to the individual child.
  * **C.** Single dose is not the recommended action for which cefalexin regimen is listed?. NICE NG111 recommends 12.5 mg/kg twice daily or 250 mg three times daily instead. For ages 5 to 11 years, NICE lists cefalexin 12.5 mg/kg twice daily or 250 mg three times daily for 7 to 10 days. Use age, size, severity and current culture information to apply the recommendation to the individual child.  
Sources: NICE NG111 recommendation 1.3.3 table 3

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