Croup vs Whooping Cough (Pertussis): Key Differences
Content reviewed against published CDC, AAP, WHO guidelines
Last reviewed:
Both croup and whooping cough cause distinctive coughing in children, but they have very different causes, durations, and treatments. Whooping cough is a bacterial infection that can be life-threatening in infants.
Key takeaways
- Croup lasts days; whooping cough lasts weeks to months
- Croup produces a single barking cough; whooping cough causes rapid-fire coughing fits with a "whoop" on inhalation
- Croup is viral and self-limited; whooping cough is bacterial and requires antibiotics
- Whooping cough is vaccine-preventable with DTaP; croup has no vaccine
: Cause
Croup: Viral (parainfluenza virus most common)
Whooping Cough (Pertussis): Bacterial (Bordetella pertussis)
: Typical age
Croup: 6 months to 3 years
Whooping Cough (Pertussis): Any age, most dangerous under 6 months
: Cough sound
Croup: Barking, seal-like cough
Whooping Cough (Pertussis): Rapid coughing fits followed by a "whoop" sound on inhale
: Duration
Croup: 2-5 days of barking cough
Whooping Cough (Pertussis): Weeks to months ("100-day cough")
: Onset
Croup: Sudden, often at night
Whooping Cough (Pertussis): Gradual; starts like a mild cold for 1-2 weeks before coughing fits begin
: Fever
Croup: Low-grade fever common
Whooping Cough (Pertussis): Often no fever or very mild
: Vomiting
Croup: Uncommon
Whooping Cough (Pertussis): Common after coughing fits (post-tussive vomiting)
: Treatment
Croup: Steroids (dexamethasone), cool mist
Whooping Cough (Pertussis): Antibiotics (azithromycin); most effective if started early
: Vaccine preventable
Croup: No
Whooping Cough (Pertussis): Yes (DTaP/Tdap vaccine)
: Contagiousness
Croup: Moderately contagious for a few days
Whooping Cough (Pertussis): Highly contagious for 3+ weeks without treatment
| Croup | Whooping Cough (Pertussis) | |
|---|---|---|
| Cause | Viral (parainfluenza virus most common) | Bacterial (Bordetella pertussis) |
| Typical age | 6 months to 3 years | Any age, most dangerous under 6 months |
| Cough sound | Barking, seal-like cough | Rapid coughing fits followed by a "whoop" sound on inhale |
| Duration | 2-5 days of barking cough | Weeks to months ("100-day cough") |
| Onset | Sudden, often at night | Gradual; starts like a mild cold for 1-2 weeks before coughing fits begin |
| Fever | Low-grade fever common | Often no fever or very mild |
| Vomiting | Uncommon | Common after coughing fits (post-tussive vomiting) |
| Treatment | Steroids (dexamethasone), cool mist | Antibiotics (azithromycin); most effective if started early |
| Vaccine preventable | No | Yes (DTaP/Tdap vaccine) |
| Contagiousness | Moderately contagious for a few days | Highly contagious for 3+ weeks without treatment |
When to Worry
- Baby turns blue or stops breathing during or after a coughing fit
- Coughing fits that last longer than 1 minute or cause vomiting
- Any infant under 3 months with a persistent cough needs urgent evaluation
- Signs of dehydration from inability to keep fluids down
- Stridor (harsh breathing sound) at rest in a child with croup
Frequently asked questions
What is the main difference between Croup and Whooping Cough (Pertussis)?
How can I tell if my baby has Croup or Whooping Cough (Pertussis)?
When should I worry?
Sources
All content follows our editorial policy and is reviewed against published clinical guidelines.
2,705 evidence-based guides6 authoritative medical sources
Bottom line
Both Croup and Whooping Cough (Pertussis) are common in young children. The key differences in symptoms can help you identify what your child may have, but when in doubt, consult your pediatrician.
Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.