31 August 2026Chapter 2: Respiratory diseasesPDF page 76Source update: October 2024
Croup
Clinical guide to croup symptoms, stridor severity, home observation, and urgent breathing signs.
This guide supports clinical education and care navigation. It does not replace bedside judgement, emergency care, specialist advice, or local treatment protocol.
Seek urgent care
- Stridor at rest, chest indrawing, blue lips, exhaustion, drooling, altered consciousness, or severe breathing difficulty.
- Poor feeding, dehydration, age under 6 months, or symptoms that worsen quickly.
- Fever with toxic appearance, severe throat pain, or concern for epiglottitis or bacterial tracheitis.
Definition and usual patient
Croup is viral laryngotracheitis or laryngotracheobronchitis, most common between 6 months and 3 years of age.
Airway swelling below the vocal cords causes the classic barking cough, hoarse voice or cry, and inspiratory stridor. Bronchial involvement can add wheeze.
Severity can change quickly, so treatment decisions are based on stridor pattern, work of breathing, oxygenation, drinking ability, and general appearance.
Clinical features and severity
- Stridor is an abnormal high-pitched inspiratory sound. Stridor at rest is a danger sign, especially with recession, tachypnoea, hypoxia, cyanosis, or fatigue.
- Keep the child calm; agitation can worsen obstruction.
- Consider another diagnosis when the child is critically ill, has drooling or tripod position, has high fever without barking cough, or fails to improve with croup treatment.
| Severity | Clinical pattern | Typical action |
|---|---|---|
| No stridor/retractions | Barking cough or hoarse voice without inspiratory stridor and without intercostal, subcostal, or sternal retractions. | Symptomatic care, hydration, and return precautions. |
| Mild croup | Inspiratory stridor only when agitated, with ability to drink and no danger signs. | Hydration, single-dose corticosteroid, and observation after treatment. |
| Severe croup | Stridor at rest, respiratory distress, hypoxia, inability to drink, exhaustion, cyanosis, or altered consciousness. | Hospital admission, oxygen if needed, IV access/hydration, nebulised epinephrine, corticosteroid, and close monitoring. |
Mild croup treatment
- Ensure adequate hydration and advise urgent return for respiratory difficulty, noisy breathing at rest, inability to drink, cyanosis, lethargy, or worsening symptoms.
- Give dexamethasone PO 0.15 to 0.6 mg/kg as a single dose, maximum 16 mg. Use the lower dose only when caregivers can return easily if symptoms recur or deteriorate; otherwise use 0.6 mg/kg.
- If dexamethasone is not available, give prednisolone PO 1 mg/kg once.
- Observe for at least 30 minutes after oral corticosteroid. Consider admission or observation longer than 4 hours if the child is under 6 months, dehydrated, or lives far from care.
Severe croup treatment
- Admit when stridor is present at rest, respiratory distress or hypoxia is present, or the child cannot drink.
- Give continuous oxygen if respiratory distress or SpO2 is below 92%; target 94% to 98% when monitoring is available. If SpO2 cannot be measured, give at least 5 litres/minute.
- Insert a peripheral IV line and provide IV hydration when oral intake is unsafe or inadequate.
- Give epinephrine by nebuliser only: 0.5 mg/kg, maximum 5 mg. Repeat every 20 minutes while danger signs persist.
- Monitor heart rate during nebulisation and stop if heart rate rises above 200/minute.
- Give dexamethasone 0.6 mg/kg once, maximum 16 mg, orally if possible; use IM or IV if vomiting prevents oral treatment. Prednisolone PO 1 mg/kg once is an alternative if dexamethasone is unavailable.
| Weight | Dose | Volume of 1 mg/ml solution | NaCl 0.9% to add |
|---|---|---|---|
| 6 kg | 3 mg | 3 ml | 1 ml |
| 7 kg | 3.5 mg | 3.5 ml | 1 ml |
| 8 kg | 4 mg | 4 ml | None usually needed |
| 9 kg | 4.5 mg | 4.5 ml | None usually needed |
| 10 to 17 kg | 5 mg | 5 ml | None usually needed |
| Weight | Dose | 2 mg tablet equivalent | 4 mg/ml ampoule volume |
|---|---|---|---|
| 6 to 8 kg | 4 mg | 2 tablets | 1 ml |
| 9 to 11 kg | 6 mg | 3 tablets | 1.5 ml |
| 12 to 14 kg | 8 mg | 4 tablets | 2 ml |
| 15 to 17 kg | 10 mg | 5 tablets | 2.5 ml |
Differential diagnosis and complications
- Suspect bacterial tracheitis when a critically ill child with croup does not improve after corticosteroid and nebulised epinephrine, especially with fever and copious purulent secretions.
- Suspect epiglottitis when onset is rapid with high fever, drooling, difficulty swallowing, tripod or sniffing position, and little or no barking cough.
- Complete airway obstruction requires intubation if possible or emergency tracheotomy by trained staff.
- Complications include hypoxia, dehydration, exhaustion, complete airway obstruction, respiratory arrest, bacterial tracheitis, pneumonia, and death.
Prevention, discharge, and handover
- Prevention is mainly general respiratory-infection prevention: hand hygiene, ventilation, reducing smoke exposure, keeping immunisations up to date, and early review of worsening breathing.
- Before discharge, ensure stridor at rest has resolved, breathing effort is improving, hydration is adequate, caregivers understand return signs, and access to urgent care is realistic.
- Handover should include age, weight, duration, stridor at rest or agitation only, retractions, SpO2, oxygen given, epinephrine dose/time/response, corticosteroid dose/route, hydration route, fever, suspected alternative diagnosis, and observation plan.
Medicines in this guide
Dexamethasone oralSingle-dose corticosteroid for mild and severe croup.Dexamethasone injectableIM or IV option when vomiting prevents oral treatment.Prednisolone and prednisone oralAlternative single-dose corticosteroid when dexamethasone is not available.Epinephrine = adrenaline injectableUsed via nebuliser for severe croup; not IM or IV for croup.Sodium chloride 0.9%Added to the nebuliser chamber when needed to reach the required volume.Ringer lactateIV hydration fluid if the child cannot drink or has dehydration.
Source
MSF Clinical guidelines - Diagnosis and treatment manual (December 2024)
This page is a paraphrased clinician-oriented guide derived from the source topic on PDF page 76. Medicine-specific details should be checked against local protocol and the linked drug-information pages.