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Croup
Keep them calm, give steroids — and know the mimics that kill. Croup is common, usually mild, and responds to a single dose of dexamethasone. Grade the severity, give nebulised adrenaline for severe distress, and look out for the toxic child who has something else. Built for revision, not live patient decisions.
Settle them, and check the basics
calm · steroidRed flags — what each should make you think
Don't upset a child with stridor. Avoid examining the throat, taking blood or forcing a mask on: crying can worsen obstruction. Keep them sitting on a parent's lap and do what you need to do quietly.
Treatment
- DxOral dexamethasone
- AdNebulised adrenaline (severe)
- O₂Oxygen
- ⏱Observe after adrenaline
- ☎Senior, anaesthetics, ENT
- 🧸Keep calm
Understand the child
recognise · gradeTypical croup
- Age 6 months to 6 years (peak around 2)
- Coryzal prodrome, then barking "seal-like" cough, hoarse voice, inspiratory stridor
- Worse at night, often comes on suddenly
- Usually viral (parainfluenza)
Severity
- Mild — barking cough, no stridor at rest, minimal recession
- Moderate — stridor at rest, recession, no distress or agitation
- Severe — stridor at rest with marked recession, agitation or lethargy, tachycardia
- Impending respiratory failure — reduced consciousness, cyanosis, reduced stridor and recession from exhaustion (sounds "better" but isn't)
The Westley score can help grade severity.
Work A–E — assess and act as you go
The diagnoses you must not miss
tap to open eachWhat points toward it, what would rule it in, and how to manage it.
Rapid onset, high fever, toxic, drooling, sitting forward ("tripod"), muffled voice, little cough; unimmunised against Hib.
Clinical — don't examine the throat or X-ray the neck.
Keep calm, senior anaesthetist and ENT immediately for airway in theatre, then IV antibiotics.
Initially croup-like, then high fever, toxic, copious secretions, poor response to adrenaline.
Clinical, airway endoscopy.
Airway support (often intubation), IV antibiotics, PICU.
Sudden onset after a choking episode, no prodrome, unilateral signs.
History, CXR (may be normal), bronchoscopy.
ENT/respiratory; follow choking algorithm if obstructed.
Sudden stridor with urticaria, swelling, wheeze after a trigger.
Clinical.
IM adrenaline. See the anaphylaxis page.
Investigate — what to order, when, and what it tells you
test with a question in mindUsually none
SpO₂
Avoid
How the plan comes together
disposition · handoverhome
Mild croup after dexamethasone, no stridor at rest, or moderate croup much improved after observation.
Safety-net: stridor at rest, working hard to breathe, drowsy, blue, drooling, unable to drink → return or call 999.
admit
Severe croup, needed nebulised adrenaline (observe at least 2–4 h and usually admit), under 6 months, recurrent or atypical, or parental concern.
Hand over: severity, dexamethasone time, adrenaline doses and times, response.
Keep the child calm, give dexamethasone to everyone, nebulised adrenaline for severe croup, and watch for the toxic, drooling child who has something worse. Nicely done getting here.
Clerking template
copy or downloadCroup — documentation structure
A structure and prompt list to help you document and think systematically. It is not a completeness check and cannot guarantee nothing is missed — use your trust's own proforma, your seniors, and your clinical judgement.
Test yourself
active recallCover the answer, say it out loud, then reveal. Retrieval beats re-reading.
0 / 10 knownFrequently asked questions
quick answersWhat are the red flags for croup?
- Stridor at rest + recession — think moderate–severe croup
- Agitation or lethargy, cyanosis — think severe / impending failure
- Toxic, drooling, sitting forward, no cough — think epiglottitis
- High fever, toxic, poor response to adrenaline — think bacterial tracheitis
- Sudden onset after choking — think foreign body
- Rash, swelling, after a trigger — think anaphylaxis
What is the initial management of croup?
- Oral dexamethasone — 0.15 mg/kg single dose for all severities (higher doses used for severe croup per local protocol); alternatives: oral prednisolone or nebulised budesonide if vomiting
- Nebulised adrenaline (severe) — 1:1000 adrenaline, 0.5 mL/kg up to 5 mL, nebulised with oxygen
- Oxygen — if hypoxic — low SpO₂ is a late, severe sign
- Observe after adrenaline — 2–4 hours (effect wears off)
- Senior, anaesthetics, ENT — for severe or impending respiratory failure
- Keep calm — sit on parent's lap
Always alongside senior support and your local guideline.
What diagnoses must you not miss in croup?
- Epiglottitis — toxic · drooling
- Bacterial tracheitis — croup that doesn't respond
- Inhaled foreign body — sudden · choking
- Anaphylaxis — stridor + rash
Open each one in the must-not-miss section for what points toward it, how to rule it in, and how to manage it.
What investigations should a junior doctor order for croup?
- Usually none — Clinical diagnosis; tests distress the child.
- SpO₂ — Gently, without upsetting.
- Avoid — Unless senior decides — risk of worsening obstruction.
Admit or discharge: how is the plan decided for croup?
- Home — Mild croup after dexamethasone, no stridor at rest, or moderate croup much improved after observation.
- Admit — Severe croup, needed nebulised adrenaline (observe at least 2–4 h and usually admit), under 6 months, recurrent or atypical, or parental concern.
Is there a clerking template for croup?
Yes — there is a free clerking template for croup on this page, structured as presenting complaint, red flags asked, history, examination (A–E), investigations, differentials, plan and escalation. You can copy it or download it as a Word document. Jump to the template.
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