Challenge Tests for Asthma - Topic Overview
Exercise challenge and inhalation challenge tests are sometimes used
asthma and workplace asthma (occupational asthma).
Exercise challenge test
In an exercise challenge test,
spirometry is done before and after you exercise on a
treadmill or an exercise bicycle. Spirometry measures how much and how quickly
you can breathe air in and out. An exercise challenge test can see what effect
exercise has on airflow.
Most people with asthma have some decreased airflow during or after
exercise. But most people who have asthma do not need an exercise challenge
Inhalation challenge test
An inhalation challenge test measures how much and how quickly you
can breathe air in and out before and after taking medicine. Spirometry may
be done before and after you are given an inhaled medicine, such as
methacholine or histamine, or after breathing cold air. The test may be
repeated for different doses of the medicine.
An inhalation challenge test is rarely needed to diagnose asthma.
But it may be used to:
- See whether the tubes that carry air to the
lungs (bronchial tubes) overreact to breathing cold air or to inhaling
methacholine or histamine. This may support a diagnosis of
- Document that asthma is present when the diagnosis is
unclear based on medical history, physical exam, and initial treatment.
You may also have a specific inhalation challenge. In this test, your
doctor exposes you to a small amount of the material that may be
causing your symptoms and then measures your lung function.