Croup vs Whooping Cough
Content reviewed against published AAP, CDC guidelines
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If your baby has been diagnosed with or you suspect croup vs whooping cough, here is what the evidence says.
The short answer
Croup and whooping cough (pertussis) are both respiratory infections that cause distinctive coughs in children, but they are different illnesses. Croup causes a characteristic barky "seal-like" cough with stridor and usually lasts 3-5 days. Whooping cough causes prolonged coughing fits followed by a "whoop" sound when gasping for air and can last weeks to months. Croup is usually mild and managed at home, while pertussis can be dangerous in young babies and requires antibiotics.
Key takeaways
- Croup and whooping cough (pertussis) are both respiratory infections that cause distinctive coughs in children, but they are different illnesses. Croup causes a characteristic barky "seal-like" cough with stridor and usually lasts 3-5 days. Whooping cough causes prolonged coughing fits followed by a "whoop" sound when gasping for air and can last weeks to months. Croup is usually mild and managed at home, while pertussis can be dangerous in young babies and requires antibiotics.
- Usually normal when: Toddler has a barky cough that is worse at night but improves during the day with no breathing difficulty
- Call your doctor if: Baby has stridor (noisy breathing) at rest that does not improve with cool air or steam
- Varies by age — see the age-by-age breakdown below
“Fever itself is not an illness — rather, it is a sign or symptom that the body is fighting an infection. Fever stimulates certain defenses, such as the white blood cells, which attack and destroy invading bacteria.”
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By Age
What to expect by age
0-3 months
Croup is uncommon in babies under 6 months. However, whooping cough is most dangerous in this age group. Young infants with pertussis may not make the classic "whoop" sound -- instead, they may have coughing spells followed by apnea (pauses in breathing), turning blue, or vomiting. Pertussis in unvaccinated or under-vaccinated young infants can be life-threatening. If your young baby has a persistent cough with any breathing pauses, seek immediate medical care.
3-6 months
Croup becomes more possible at this age. It typically starts with cold symptoms, then develops a barky cough and possibly stridor (noisy breathing) that worsens at night. Cool mist and sitting in a steamy bathroom can help mild croup. Whooping cough at this age starts with 1-2 weeks of cold-like symptoms, then progresses to severe coughing fits that can cause choking, vomiting, or exhaustion. Your baby should be up to date on DTaP vaccination.
6-12 months
Croup is most common between 6 months and 3 years. The barky cough, hoarse voice, and stridor are usually worst on the second or third night, then improve. Croup rarely lasts more than a week. Whooping cough, by contrast, can cause coughing fits for 6-10 weeks (the "hundred-day cough"). The cough is typically worse at night and can be triggered by feeding, crying, or activity. Between coughing spells, the child may seem relatively normal.
12 months+
Croup remains common in toddlers and typically causes a distinctive seal-like bark, hoarseness, and worsening symptoms at night. Most cases resolve in 3-5 days. Severe croup with persistent stridor at rest may require oral dexamethasone or nebulized epinephrine in the emergency department. Whooping cough in vaccinated toddlers tends to be milder but can still cause prolonged coughing fits. A nasal swab PCR test can confirm pertussis.
What Should You Do?
When to take action
- Toddler has a barky cough that is worse at night but improves during the day with no breathing difficulty
- Croup symptoms improve with cool air or steam and child can drink fluids comfortably
- Cough from a cold is getting better after 7-10 days
- Child has a brief coughing spell during a cold but recovers quickly and breathes normally between episodes
- Barky cough lasts more than 5 days or recurs frequently
- Child has persistent coughing fits lasting more than 2 weeks, especially with vomiting or a "whoop" sound
- Your baby or toddler has been exposed to someone with confirmed pertussis
- Baby has stridor (noisy breathing) at rest that does not improve with cool air or steam
- Baby turns blue, stops breathing, or becomes extremely lethargic during a coughing spell -- call 911 immediately
Doctor Visit Checklist
Bring this checklist to your next pediatrician visit to discuss Croup vs Whooping Cough.
Things to mention
- Barky cough lasts more than 5 days or recurs frequently
- Child has persistent coughing fits lasting more than 2 weeks, especially with vomiting or a "whoop" sound
- Your baby or toddler has been exposed to someone with confirmed pertussis
Observations to share
- Barky cough lasts more than 5 days or recurs frequently
- Child has persistent coughing fits lasting more than 2 weeks, especially with vomiting or a "whoop" sound
- Your baby or toddler has been exposed to someone with confirmed pertussis
Urgent signs to report immediately
- Baby has stridor (noisy breathing) at rest that does not improve with cool air or steam
- Baby turns blue, stops breathing, or becomes extremely lethargic during a coughing spell -- call 911 immediately
My notes
From ismybabyalright.com — free, evidence-based baby health guides
Related Resources
Frequently asked questions
Is croup vs whooping cough normal?
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Is croup vs whooping cough normal at 0-3 months?
Is croup vs whooping cough normal at 3-6 months?
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Does croup vs whooping cough go away on its own?
References
All content follows our editorial policy and is reviewed against published clinical guidelines.
2,705 evidence-based guides6 authoritative medical sources
Related Resources
Bottom line
Most cases of croup vs whooping cough are normal. Talk to your pediatrician if baby has stridor (noisy breathing) at rest that does not improve with cool air or steam.
Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.
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