28/11/2025
We are participating in the annual meeting of the Danish Respiratory Society in Odense. Today, we organized the symposium entitled «Use of the Provocholin Test to Exclude Asthma Diagnosis in Post-COVID Cough».
The session was chaired by Professor Vibeke Backer, and the lecture was delivered by Professor Ole Hilberg.
Use of Provocholin (Methacholine) Test to Exclude Asthma Diagnosis in Post-COVIDCough
Background
After COVID-19 infection, many patients experience persistent cough. It is important to differentiate whether this cough is caused by asthma or other reasons. One of the most commonly used methods to assess airway reactivity and hyperreactivity is the methacholine challenge test using Provocholin.
What is Provocholin (methacholine)?
Provocholin is a cholinergic muscarinic receptor agonist that, when inhaled, can induce bronchoconstriction, especially in individuals with hyperreactive airways as seen in asthma.
Purpose of the test
The Provocholin test is primarily used to detect or exclude airway hyperreactivity, a characteristic feature of asthma. A negative test has a high negative predictive value and can therefore be useful in excluding an asthma diagnosis in patients with persistent cough after COVID-19 (Cockcroft et al., 2012).
Interpretation
- Negative test: Indicates a low likelihood of asthma, and asthma diagnosis can be excluded with high confidence (Cockcroft et al., 2012).
- Positive test: Supports an asthma diagnosis but should always be interpreted in the context of clinical symptoms and other investigations (O’Byrne & Inman, 2003; Andersson & Janson, 2009).
Use in post-COVID cough
Since many patients with post-COVID syndrome have cough without a clear asthmatic cause, the methacholine challenge test can be a valuable tool to exclude asthma as the cause of symptoms. A negative test can thus spare patients unnecessary asthma treatment.
