CCFP priority topic 21 of 105
Croup on the CCFP exam
6 key features, the mistakes that cost marks, and a practice question.
Checked by a Canadian family physician, MD, CCFP. Updated October 20, 2026.
What the exam tests
Key features
The CFPC’s 6 key features for Croup. Each one below has how the exam asks it, the common mistakes and the approach.
Practice question
Try one before you read
A real case from the bank, in the new short-menu format. Answer it first. Then read the key features.
Key feature 1 of 6
Airway danger
Spot the child with croup who is tiring out, and treat the airway fast.
CFPC skill Selectivity, clinical reasoningPhase Hypothesis generation, diagnosis, treatmentSources Canadian Paediatric Society
On the exam
A drowsy 11-month-old with soft stridor in your office, 45 minutes from hospital. Expect one best answer.
Pick the first treatment.
Common mistakes
Reading quieter stridor in a drowsy child as getting better. Or giving dexamethasone alone: it takes 2 to 3 hours to work.
Approach
- Check airway, breathing and circulation first. Then grade severity on cough, stridor (a harsh noise on breathing in), retractions, behaviour and colour.
- Retractions are skin sucking in between or under the ribs. Visible at rest, they mean at least moderate croup.
- Impending failure: drowsy or less alert, dusky or blue without oxygen. Cough and stridor can go quiet as the child tires.
- Moderate or severe croup: give nebulized epinephrine. The dose is 5 mL of 1:1000 L-epinephrine, the same at any age or weight.
- Give dexamethasone as well. Epinephrine works in 10 to 30 minutes; the steroid takes 2 to 3 hours.
- Epinephrine wears off by about 2 hours. After it and dexamethasone, watch 2 to 4 hours before the child goes home.
- Severe croup or impending failure with a poor or short-lived response: call intensive care or anaesthesia. Keep the child calm and avoid frightening them.
| Severity | Cough and stridor | Chest, behaviour, colour |
|---|---|---|
| Mild | Occasional bark. Little or no stridor at rest. | No or mild retractions. No distress. |
| Moderate | Frequent bark. Stridor easy to hear at rest. | Retractions at rest. Little distress. |
| Severe | Frequent cough. Loud stridor on breathing in, sometimes out. | Marked retractions. May be very drowsy. |
| Impending failure | Cough and stridor may go quiet as the child tires. | Retractions may ease. Drowsy or less alert. Dusky or blue without oxygen. |
Key feature 2 of 6
Croup mimics
Rule out the dangerous look-alikes before you settle on croup.
CFPC skill Clinical reasoning, selectivityPhase Hypothesis generation, diagnosisSources Canadian Paediatric Society
On the exam
A toddler with stridor and a high fever. Expect a short menu (pick several from a list) of findings.
Pick the findings that point away from croup.
Common mistakes
Calling every stridor croup. A toxic (very unwell-looking), drooling child, a choking spell, or sudden hives and wheeze each point to a more dangerous cause.
Approach
- Typical croup: age about 6 months to 3 years, a cold first, then barky cough, hoarse voice and stridor.
- Red flags for another cause: a very unwell (toxic) look, drooling, trouble swallowing.
- No barky cough argues against croup, above all with drooling and a sudden high fever.
- High fever and a poor response to nebulized epinephrine: think of bacterial tracheitis (a bacterial infection of the windpipe).
- Croup under 6 months, or croup that repeats, drags on or is unusually severe: look for a narrowed airway. Refer to ear, nose and throat.
- Long croup with fever may mean a bacterial infection on top.
| Cause | Clues |
|---|---|
| Epiglottitis | No barky cough. Sudden high fever, drooling, trouble swallowing. Looks toxic or anxious, sits forward in a sniffing position. |
| Bacterial tracheitis | High fever, toxic look, poor response to nebulized epinephrine. |
| Abscess behind or beside the throat | High fever, neck pain, sore throat, trouble swallowing. Later a twisted neck and drooling. |
| Inhaled foreign body | A choking spell, wheeze, hoarse voice, noise on breathing in and out, less air entry. |
| Anaphylaxis | Fast onset of trouble swallowing, wheeze and stridor, sometimes hives. |
Key feature 3 of 6
Upper or lower airway
In a child with cough or noisy breathing, sort upper airway signs from lower airway signs.
CFPC skill Clinical reasoningPhase History, physicalSources Canadian Paediatric Society
On the exam
A parent calls an 11-month-old wheezy after a cold. Expect a short menu (pick several from a list) of findings.
Pick the findings that locate the noise.
Common mistakes
Leaning on the cold, the fever or the daycare viruses. Both croup and bronchiolitis follow a cold with fever, so none of these places the noise.
Approach
- Upper airway, as in croup: harsh noise on breathing in, barky cough, hoarse voice.
- Lower airway, as in bronchiolitis: fast breathing, wheeze and crackles (fine popping sounds in the chest), with nasal flaring, retractions or grunting.
- Bronchiolitis affects children up to 24 months. It usually brings a first wheeze before 12 months.
- Two to three days of fever, cough and runny nose come before bronchiolitis. A cold comes before croup too, so it cannot separate them.
- Noise on breathing in and out with a choking spell and less air entry: think of an inhaled foreign body.
- Salbutamol is rarely useful in croup. In clear bronchiolitis, a salbutamol trial is not advised either.
| Croup: upper airway | Bronchiolitis: lower airway | |
|---|---|---|
| Main noise | Harsh noise on breathing in | Wheeze and crackles |
| Other signs | Barky cough, hoarse voice | Fast breathing, flaring, retractions, grunting |
| Usual age | About 6 months to 3 years | First wheeze, usually before 12 months |
| Salbutamol | Rarely useful | Not advised in routine cases |
Key feature 4 of 6
No tests needed
Diagnose typical mild or moderate croup from the story and exam alone.
CFPC skill Clinical reasoning, selectivityPhase Diagnosis, investigationSources Choosing Wisely Canada
On the exam
A father asks for a chest X-ray for his barking toddler. Expect a short menu (pick several from a list) of tests.
Pick which tests to order, if any.
Common mistakes
An X-ray to reassure the father. In typical croup it rarely finds anything, and it adds radiation, cost and antibiotics.
Approach
- Do not X-ray a child with croup. Films rarely show anything important and add radiation, cost and a longer emergency stay.
- X-rays that find nothing important are linked to antibiotics the child did not need.
- Image only with a strong reason: low oxygen, focal signs on the lung exam, a long illness or severe distress.
- Skip the viral panel for a suspected viral illness.
- Consider one only in a high-risk child, such as one with weak immunity, or when the result will change treatment.
Key feature 5 of 6
Steroids for all
Give a steroid to every child with croup, the mild cases included.
CFPC skill Clinical reasoningPhase TreatmentSources Canadian Paediatric Society
On the exam
A toddler with a barky cough who breathes quietly at rest. Expect one best answer.
Pick the treatment for mild croup.
Common mistakes
Holding back the steroid because the child is quiet at rest. Every severity gets one. Mist, steam or salbutamol in its place is wrong too.
Approach
- Give a steroid to every child with croup, mild to severe. Dexamethasone 0.6 mg/kg by mouth once is the dose most trials used.
- By mouth is preferred: less vomiting. Give it into the muscle if the child keeps vomiting or is in marked distress.
- It starts working in about 2 to 3 hours. The benefit lasts 24 to 48 hours.
- Lower doses of 0.15 to 0.3 mg/kg: it is unclear if they work as well. Oral prednisolone worked as well in two studies.
- Adding inhaled budesonide gave no extra benefit in children admitted to hospital.
- Humidified air has no evidence behind it, and mist tents are not advised. Treat fever and discomfort with a fever medicine.
- Antibiotics are rarely needed. Bacterial infection in croup is very uncommon.
Key feature 6 of 6
Talking to parents
Take the parents' fear seriously, explain that croup comes and goes, and plan for night flares.
CFPC skill Clinical reasoning, communicationPhase Treatment, follow-upSources Canadian Paediatric Society
On the exam
A worn-out father calls the night after the steroid: the bark is back. Expect a short menu (pick several from a list).
Pick what to tell the father tonight.
Common mistakes
Telling the father it is over because the child looks calm now. Croup often worsens at night for several days. Steam as the plan is wrong too.
Approach
- Name what the parents went through. Croup is frightening to watch; do not wave it off.
- Explain the course: symptoms usually last 3 to 7 days and are often worse at night.
- The bark settles within 48 hours in about 60% of children. Fewer than 5% have symptoms past five nights.
- A flare at night fits the usual course. One dose of dexamethasone covers 24 to 48 hours.
- Tell them the steroid also improves sleep and eases parents' stress.
- Stridor or retractions at rest, drowsiness or a dusky colour mean at least moderate croup. The child needs to be seen now.
- Fewer than 5% have a second episode. Repeated episodes go to ear, nose and throat.
Flashcards
Answer it first, then check.
KF 1A child with croup is drowsy and the stridor has gone quiet. What does it mean?
Possible impending respiratory failure. Give nebulized epinephrine; call intensive care or anaesthesia if the response is poor or short-lived. Source: Canadian Paediatric Society
KF 1What nebulized epinephrine dose does a 9 kg infant with severe croup get?
5 mL of 1:1000 L-epinephrine. The dose is the same at any age or weight. Source: Canadian Paediatric Society
KF 1How long do you watch a child after epinephrine and dexamethasone?
2 to 4 hours. Home is safe if symptoms do not come back in that time. Source: Canadian Paediatric Society
KF 2Stridor, drooling, a sudden high fever and no barky cough. What do you think of?
Epiglottitis. A toxic or anxious child sitting forward in a sniffing position fits it too. Source: Canadian Paediatric Society
KF 3Harsh noise on breathing in, a hoarse voice and a barky cough. Upper or lower airway?
Upper airway, as in croup. Wheeze and crackles with fast breathing point to the lower airway. Source: Canadian Paediatric Society
KF 4A child has typical croup. When would you order an X-ray?
Only for low oxygen, focal signs on the lung exam, a long illness or severe distress. Source: Choosing Wisely Canada
KF 5What steroid and dose do you give a child with mild croup?
Dexamethasone 0.6 mg/kg by mouth, as a single dose. Mild croup needs it too. Source: Canadian Paediatric Society
KF 6How long does croup usually last, and when is it at its worst?
Usually 3 to 7 days. Symptoms are often worse at night, so plan for tonight. Source: Canadian Paediatric Society
FAQ
Do I need an X-ray to confirm croup?
No. Choosing Wisely Canada advises against X-rays in croup. Diagnose it from the story and exam.
Why does the dose say L-epinephrine, not racemic epinephrine?
Racemic epinephrine is hard to get in Canada. The Canadian Paediatric Society gives 5 mL of 1:1000 L-epinephrine as the match for 0.5 mL of racemic epinephrine.
Does cool air or steam help croup?
Humidified air has no evidence behind it, and mist tents are not advised. On the exam, the steroid and a clear plan for night flares earn the marks, not steam.
What age is typical croup?
About 6 months to 3 years. Outside that range, or with repeated, long or unusually severe episodes, look for another cause and think about an ear, nose and throat referral.
Sources
Written from the CFPC Assessment Objectives and Canadian guidelines first. Checked by a Canadian family physician, MD, CCFP.
Last reviewed October 20, 2026For exam study. Not advice for a patient in front of you.
- Assessment Objectives for Certification in Family Medicine, 2nd editionCollege of Family Physicians of Canada · 2020
- Position statements and practice pointsCanadian Paediatric Society
- Choosing Wisely recommendationsChoosing Wisely Canada