Question
Please tell me the details of cough-variant asthma, its diagnosis, and how it differs from other types of asthma.
C.D.S. Katoch, MD
Response from Richard J. Martin, MD
The 3 most common causes of chronic cough are sinusitis, gastroesophageal reflux, and asthma. A given patient may have all 3 of these conditions, producing the presenting complaint of cough. In regard to cough-variant asthma, wheezing is considered to be sine qua non of asthma; however, it has been recognized that chronic cough alone can be secondary to asthma. One of the first reports of cough-variant asthma reported on 6 patients whose symptom was persistent cough without wheezing or dyspnea.[1] There was no past history of asthma, and the baseline spirometry was normal. However, bronchial hyperresponsiveness testing was positive, and coughing abated with bronchodilators.
Cough-variant asthma should not be considered as a distinct entity separate from classic asthma. The reason for this is that these individuals also have significant airway inflammation with predominance of eosinophils.[2] Thus, treatment of cough-variant asthma is done with anti-inflammatory therapy (inhaled corticosteroids) and short-acting bronchodilator as needed. One can consider using ipratropium bromide (2 actuations, 4 times a day as needed). The cough receptors may be blocked by inhaled ipratropium. If this is used, it should be in addition to anti-inflammatory therapy.
Medscape Pulmonary Medicine. 2003;5(2) © 2003 Medscape
Cite this: Richard J Martin. Cough-Variant Asthma - Medscape - Dec 11, 2003.
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