Are all “croup coughs” caused by croup?
© 2014 Roy Benaroch, MD
“I had to bring my son in again for that croup cough. What does it mean if he keeps getting that?”
“Croup” is one of those funny words that different people use to mean different things. And sometimes using the word locks us into a certain specific diagnosis that might be wrong. I try to get parents to just avoid the word entirely. Instead of saying “croup”, just tell me what the cough actually sounds like. Or better yet, bring a video.
To a pediatrician, a “croupy cough” or a “croup-like cough” is a very specific, odd sort of cough. It sounds—really—like a small dog or seal barking. It is not a deep cough (at least not the way I think of that word), nor is it “dry” or “wet” or “chesty”.
Here’s a very typical conversation:
Mom: “He’s got that croup again!”
Me: “What does the cough sound like?”
Mom: “You know, that croup cough.”
Me: “So, what does it sound like?”
Mom: “You know, all deep in his chest.”
Me: “That’s not what croup sounds like. Does it sound like a seal or a dog?”
Mom: “Yes. It’s a chesty croup cough.”
But croup doesn’t sound chesty or deep at all. Mom and I are getting tied up in the language and not really paying attention to what the child really sounds like. Conversations like these muddy the diagnosis. In my experience, most kids with recurrent “croup” don’t have recurrent croup at all—they just have a cough, and somewhere along the line someone called it croup, and that’s the diagnosis that has stuck.
Croup rule #1: Is the cough really barky, like a seal or dog? If not, it isn’t croup.
There’s more, too. Even if the cough does sound barky, your child still may not have croup. Other things cause a barky cough, too. “Croup”, the illness, is a viral infection of the upper airway usually caused by a virus called “parainfluenza” (occasionally, other viruses can cause croup, too). Other symptoms usually include a mild fever, hoarse voice, and a sore throat that’s lower down on the neck than a typical sore throat. Appetites might be low, and there will probably be some runny nose. A more-severe case of croup will be accompanied by a breathing noise called “stridor,” which is a high pitched inhaling noise that gets worse at night. A “croupy cough” that’s not accompanied by these other findings is less likely to really be a case of croup, and someone had better remember to at least think about that possibility. Other causes of croup cough can include:
- Asthma, especially if recurrent
- A foreign body in the airway
- A mass in the airway
- A loose kind of airway (some kids are born that way, and their coughs always sound kind of croupy, though it isn’t really “croup”)
Croup rule #2: Not all croupy coughs are caused by croup.
There’s no single test that definitively tells you that it’s croup. A viral swab of the nose can show if parainfluenza virus is around (though not all croup is caused by parainfluenza, and parainfluenza itself can cause infections other than croup.) An x-ray of the neck can reliably show swelling and changes that are very suggestive of croup—and can effectively “rule out” other possibilities. Sometimes a chest x-ray can be helpful, too. But the bottom line is that the diagnosis depends on the overall picture. The exact sound of the cough is important, but doesn’t make the diagnosis alone. Doctors and parents need to keep an open mind, and not label all that barks as croup.
By the way, that virus—parainfluenza—it’s confusing the way we’ve named these things. Parainfluenza has nothing much to do with influenza, which is a different virus completely. Influenza vaccines don’t prevent parainfluenza infections. Parainfluenza commonly causes croup in babies and young children, and also causes “laryngitis” (sore throat and hoarse voice) in older kids and adults. It can sometimes also cause a viral pneumonia in young people, or sometimes a wheezy chest infection called “bronchiolitis.” Yikes!
Next up: what to do when your child has the croup.