Childhood Asthma OSCE - Viral-Induced Wheeze

Case Overview

• Age/Sex: 8-year-old male
• Occupation: Schoolboy (Year 3)
• Setting: Emergency department / urgent clinic with parent as historian
• Chief complaint: "He's been wheezing and coughing"

Patient Script

Who I Am

I'm his mother — he's an 8-year-old schoolboy who's usually very active and plays football at breaktime.

What Brings Me In

He's had a bad cough and noisy breathing for a few days and tonight it's much worse so I brought him in.

My Story

He had a runny nose and sore throat starting on Monday, and then he began coughing more on Tuesday night. Over the last 3 days the cough has got worse and tonight he has noisy breathing — I can hear a wheeze when he breathes out. He has been worse in the evening and wakes at night coughing. He had a low-grade fever at home yesterday (about 38.2°C) but it came down with paracetamol. I gave him his blue inhaler once this morning from an old spacer at home and it helped him a bit but the wheeze came back after a couple of hours. He has had a couple of similar episodes with colds before when he was younger but he was never diagnosed with asthma and he doesn’t use an inhaler regularly. He has no difficulty swallowing and he is still drinking small amounts but not as much as usual.

My Medical Background

• Past medical history: occasional wheeze with colds as a toddler, no formal diagnosis of asthma
• Regular medications: none regularly; I keep a blue salbutamol inhaler and spacer at home from a previous episode (used once today)
• Allergies: none known
• Social: lives with both parents and a 5-year-old sibling; family have a pet dog at home
• Family history: my sister has asthma and uses an inhaler
• Vaccinations: up-to-date
• Red herrings: he had a chest infection 18 months ago and got antibiotics then; he had ibuprofen this afternoon for fever; his little brother had a croupy cough last week at school

What I Think & Worry About

• I think this is another cold but I worry his breathing sounds bad and he might stop breathing.
• I want to know if he needs antibiotics or a steroid inhaler to stop this now.
• I'm worried he might need to go to hospital if it gets worse tonight.

If You Ask Me About Other Symptoms...

• Fever: had a mild fever yesterday (around 38.2°C), down after paracetamol
• Feeding/drinks: drinking less than usual but taking small sips; no vomiting
• Cough: mainly dry with some rattly sounds; worse at night
• No choking episode or sudden onset that would suggest something stuck in the airway
• No rash, no tongue or lip swelling, no known new foods or obvious allergy exposure
• Activity: quieter than usual, sitting up more and not running about

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Clinical Summary

Examination

• General: alert, mildly distressed by coughing
• Temperature: 37.9°C
• Heart rate: 110/min (sinus, regular)
• Respiratory rate: 30/min (slightly elevated for age)
• SpO2: 95% on room air
• Work of breathing: mild intercostal retractions on exertion, no central cyanosis
• Chest auscultation: diffuse bilateral expiratory wheeze louder on forced expiration, no focal crepitations
• Upper airway: congested nasal mucosa, no stridor at rest
• Other systems: cardiovascular exam normal, no clubbing, peripheral perfusion normal

Investigations

• SpO2 on room air: 95% (mild hypoxia borderline)
• Peak expiratory flow (approx): 220 L/min (about ~65–75% predicted for his height — indicates reduced flow)
• Chest X-ray: hyperinflation, no lobar consolidation (interpretation: supports viral/reactive airways picture rather than focal bacterial pneumonia)
• Nasopharyngeal viral PCR: rhinovirus positive (interpretation: viral trigger likely)
• Full blood count: WCC 8.5 x10^9/L, neutrophils 4.5 x10^9/L, lymphocytes 3.0 x10^9/L (interpretation: no marked bacterial leukocytosis)
• C-reactive protein: 6 mg/L (interpretation: low, argues against significant bacterial infection)

Diagnosis

• Primary diagnosis: Viral-induced wheeze (post-viral/reactive airways exacerbation)

  • Evidence: recent upper respiratory tract prodrome, audible expiratory wheeze, radiographic hyperinflation, positive rhinovirus PCR, low CRP and non-elevated WCC, partial response to inhaled beta-agonist.

• Important differentials:

  • Asthma exacerbation: family history of asthma and previous episodic wheeze make this a consideration, but absence of chronic symptoms and typical pattern of onset with viral URTI favours viral-induced wheeze.
  • Bacterial pneumonia: considered because of fever and cough, but CXR shows no focal consolidation and inflammatory markers are low, making this less likely.
  • Foreign body aspiration: sudden onset and unilateral findings would be expected; this history is of gradual onset with bilateral wheeze so foreign body less likely.
  • Anaphylaxis/allergic reaction: would expect urticaria, angioedema, or hypotension; not present here.

Management

• Immediate
  • Give inhaled short-acting beta-2 agonist with spacer (salbutamol 100 mcg puffs): give 2–6 puffs via spacer, reassess after 10–20 minutes; repeat up to three doses as needed.
  • Monitor oxygen saturation and work of breathing; give supplemental oxygen only if SpO2 < 92% or if clinical distress increases.
  • If poor response or moderate–severe distress, give nebulized bronchodilator and consider urgent paediatric review.
• Pharmacologic
  • Consider a short course of oral prednisolone (e.g., 1 mg/kg once daily for 3 days) if there is significant airway obstruction or poor response to bronchodilator, noting steroids are of variable benefit in purely viral wheeze but are often used in school-aged children with severe symptoms.
  • Do not give antibiotics routinely unless there is clinical or radiological evidence of bacterial pneumonia.
• Discharge and follow-up
  • If improved and stable, discharge with salbutamol inhaler + spacer and instructions for use (demonstrate technique).
  • Provide a written safety-netting plan: return if increased work of breathing, difficulty feeding, SpO2 < 92% on room air, persistent high fever, or worsening over 24–48 hours.
  • Arrange follow-up with GP or paediatric clinic within 48–72 hours for review and consideration of asthma assessment if recurrent episodes.
  • Educate family about triggers, inhaler use, and when to seek urgent care.

Key Learning Points

• Viral-induced wheeze commonly follows an upper respiratory tract infection and presents with noisy breathing, cough, and expiratory wheeze, often improving with bronchodilator but not necessarily indicating chronic asthma.

• Differentiate from bacterial pneumonia (look for focal consolidation, high CRP/WCC) and foreign body aspiration (often sudden onset and focal findings); use clinical exam, CXR, and basic labs to guide management.

• Management prioritises bronchodilator therapy and supportive care, selective use of systemic corticosteroids based on severity and age, and avoidance of unnecessary antibiotics; ensure clear safety-netting and follow-up for recurrent or persistent symptoms.