Diagnosing Asthma in Young Children

Most children who have asthma develop their first symptoms before 5 years of age. However, asthma in young children (infants to children 5 years old) can be hard to diagnose.

Sometimes it's hard to tell whether a child has asthma or another childhood condition. The symptoms of asthma are similar to the symptoms of other conditions.

Also, many young children who wheeze when they get colds or respiratory infections don't go on to have asthma. A child may wheeze because he or she has small airways that become narrow during colds or respiratory infections. The airways grow as the child grows, so wheezing no longer occurs as the child gets older.

A young child who has frequent wheezing with colds or respiratory infections is more likely to have asthma if:

• One or both parents have asthma
• The child has signs of allergies, including the allergic skin condition eczema
• The child has allergic reactions to pollens or other airborne allergens
• The child wheezes even when he or she doesn't have a cold or other infection

The most certain way to diagnose asthma is with a lung function test, a medical history, and a physical exam. However, it's hard to do lung function tests in children younger than 5 years. Thus, doctors must rely on children's medical histories, signs and symptoms, and physical exams to make a diagnosis.

Doctors also may use a 4–6 week trial of asthma medicines to see how well a child responds.