Asthma is one of the most common chronic conditions in the United States. It usually presents itself through distinct symptoms that include wheezing and a cough.
Sometimes asthma comes in a form called cough variant asthma (CVA), which doesn’t have typical asthma symptoms. Below we detail the differences between CVA and regular chronic asthma.
CVA is only defined by one symptom: a chronic cough that can’t be explained by other causes. This cough is usually dry and lasts at least six to eight weeks. It doesn’t include some of the other defining symptoms of asthma, such as:
- chest tightness
- wheezing when exhaling
- shortness of breath
- fluid in the lungs
- cough with phlegm or mucus
- trouble sleeping due to any of the above symptoms
Even though CVA doesn’t present symptoms other than coughing, it often causes increased inflammation in the airways. So, it’s very important to manage CVA properly.
If left untreated, CVA can progress into more severe, chronic asthma. A recent study notes “30 to 40 percent of adult patients with CVA, unless adequately treated, may progress to classic asthma.” Another study indicated that CVA is one of the most common causes of coughing worldwide.
Another study from Japan noted that in 42 percent of people, an unexplained, persistent cough was attributed to CVA. About 28 percent could be explained by cough-predominant asthma, which is closely related to CVA. Persistent coughing can also indicate other conditions such as postnasal drip and GERD.
Just like with standard chronic asthma, scientists don’t know what causes CVA. One potential reason is that allergens such as pollen may cause coughing. Another is that infections in the respiratory system may trigger coughing episodes.
Scientists believe that CVA in some people may be associated with taking beta-blockers. These drugs are generally used to treat a variety of conditions that include:
- heart disease
- heart failure
- abnormal heart rhythms
Beta-blockers are also found in eye drops used to treat glaucoma. Aspirin may also contribute to the cough associated with CVA.
Diagnosing CVA can be challenging. It only has one notable symptom. People with CVA may also have normal results for pulmonary tests, such as spirometry, used to diagnose regular asthma.
Doctors often use the methacholine challenge test to diagnose CVA. In this test, you inhale methacholine in the form of an aerosol mist while doing spirometry. Your doctor then monitors the airways as they expand and narrow. If your lung function declines by at least 20 percent during the test, then the doctor will diagnose asthma.
The methacholine challenge test is often done in a special facility. If a doctor suspects CVA, they may start asthma treatment without a definitive diagnosis. If it helps manage your cough, this can confirm CVA.
CVA can be treated with treatments for chronic asthma. These methods include:
- Inhaled corticosteroids (inhalers): One of the most important methods of treating CVA is to use inhaled corticosteroids, also known as inhalers. This medication controls cough, prevents the onset of wheeze, and reduces airway obstruction in people with CVA. If you have CVA or chronic asthma, it’s best to take inhalers daily as prescribed. Examples include budesonide (Pulmicort) and fluticasone (Flovent). You can learn more about which corticosteroid is best for you at Partners Healthcare Asthma Center.
- Oral medications: Doctors often supplement inhalers with oral pills called leukotriene modifiers. They help relieve asthma symptoms for 24 hours. Examples include montelukast (Singulair) and zileuton (Zyflo).
- Bronchodilators: These substances relax the muscles that tighten around the airways, leading them to open. They can act short-term or long-term. Short-term bronchodilators, such as albuterol, are used to relieve asthma symptoms during an attack or before intense exercise. They aren’t used in the daily treatment of asthma. In contrast, long-term bronchodilators are used with inhaled steroids on a daily basis to manage chronic asthma. Beta-2 agonists are another example of bronchodilators, and can be short-term or long-term acting.
- Nebulizers: Sometimes doctors will prescribe a nebulizer if other medications aren’t working for you. Nebulizers automatically spray medication in a mist through a mouthpiece. This allows the lungs to easily absorb the medication.
CVA is an unusual, but common form of asthma. It can be managed like regular chronic asthma. If you have a persistent, dry cough that lasts for six weeks or longer, visit an asthma specialist to get a proper diagnosis.
There are several ways to help prevent asthma attacks if you have CVA:
- Be consistent with your medication. This is perhaps the most important thing you can do to manage your asthma. Taking daily medications, such as inhalers, is essential for making progress. If you’re having coughing attacks, taking strong, short-acting medications is also important.
- Avoid allergens. Certain allergens can trigger or worsen asthma symptoms. These can include air pollution, animal fur, and pollens in the air. A study from 2014 indicated that allergens, especially pollen, might increase inflammation in the air pathways of people with CVA.
- Make lifestyle changes. Humidifiers can improve moisture in the air, which is favorable for people with asthma. An analysis of research in the Cochrane Review suggests that yoga may improve asthma symptoms. However, more trials are needed to confirm this.
- Avoid smoking. Smoking will trigger coughing if you have CVA, and other symptoms if you have chronic asthma. It will also increase your risk for other lung and breathing conditions.
- Use your peak flow meter. This is a great way to see your progress with asthma and whether or not you should see you doctor for a follow-up.
- Exercise regularly. Exercise improves blood flow and lung capacity, and reduces anxiety. Many people who take the proper medication find exercise to be a wonderful way to manage their symptoms of CVA.