Risk is not destiny—but knowing the risk can help.
Asthma can seem to appear suddenly. A child gets a cold, starts coughing or wheezing, needs an inhaler—and eventually someone says, “This looks like asthma.”
But clues can appear long before the diagnosis is obvious.
We cannot look at a healthy baby and predict with certainty who will develop asthma. There is no single blood test, genetic test, or symptom that gives us the answer.
What we can do is recognize patterns that substantially change the risk.
Some important clues aren't breathing problems at all. They include eczema, food allergy, and having a parent with asthma.
Wheezing is another important clue—but one episode of wheezing with a viral infection does not predict asthma very well. Repeated episodes are much more meaningful, particularly when wheezing occurs without a cold.
Another under-recognized clue is recurrent croup. One ordinary episode of croup is common and does not tell us much about future asthma. But repeated episodes are different. Children with recurrent croup have a higher risk of later asthma, particularly when other clues such as eczema or allergies are also present.
Doctors have combined some of these findings into validated prediction tools. One of the best known is the Asthma Predictive Index (API). In a young child with recurrent wheezing, asthma becomes substantially more likely when that child also has eczema, a parent with asthma, allergic disease, or wheezing apart from ordinary colds.
Recurrent croup is not part of the traditional API, but it is another piece of the pattern worth paying attention to.
The important point is:
One clue tells us a little. A pattern can tell us much more.
For example, a young child with eczema, several wheezing episodes or recurrent croup, and a parent with asthma deserves particularly close follow-up. If breathing symptoms continue, recognizing that pattern early can help us diagnose and treat asthma sooner.