Prescribed bronchial challenge: why after normal spirometry?

New breathlessness without signs of respiratory distress needs medical assessment the same day. In France, call 15 or 112 immediately if it prevents you from finishing sentences or comes with bluish lips or changes in alertness. Do not wait for a planned bronchial challenge with these signs.

The doctor may propose a bronchial challenge when symptoms suggest asthma but spirometry is normal. This test examines airway reactivity: how the bronchi respond to an inhaled substance. The prescription addresses an unresolved question in the assessment; it does not confirm asthma on its own.

In the test described by Ameli, a substance such as methacholine may narrow the airways. Breathing measurements are repeated to observe their response. A reversibility test answers a different question: measurements are repeated after a medicine that opens the airways. Clarify which test is planned.

A methacholine challenge requires specialist medical supervision. Its official product information requires a trained doctor, immediate availability to intervene and emergency equipment. The airway narrowing induced during the examination explains this supervision. Ask the team which symptoms to report during the test and how it manages them.

A positive response shows airway hyperreactivity, which can also occur in other circumstances. The official product information lists allergic rhinitis without asthma, smoking and recent respiratory infections among the factors to consider. The doctor therefore interprets the result alongside your history and the other examinations.

Before the appointment, give the team your medication list and report a recent respiratory infection. Some medicines affect the reactivity being measured. Confirm the instructions for each medicine, including regular asthma treatments; the doctor decides whether any should be paused. Also ask who will discuss the result and its interpretation limits with you.