Imagine a cough that’s more than just a nuisance — it could be a hidden sign of something called cough-variant asthma (CVA). This type doesn’t follow the expected pattern of a typical cough and might be easily overlooked.
Cough is common in children and isn’t always a sign of asthma. Cough-variant asthma is a specific type of asthma in which the only symptom may be a dry, nonproductive cough (a cough that doesn’t produce mucus). Diagnosing CVA can be difficult because many conditions and illnesses can cause a dry cough that lasts more than two months. In adults, asthma can cause a cough in 25 percent to 30 percent of nonsmokers with chronic (long-term) cough. With CVA, a certain substance or situation can trigger symptoms.
In this article, we’ll discuss what cough-variant asthma is, how it differs from classic asthma, and how it’s treated. The sooner you start treatment, the less likely you are to develop classic asthma later.
When you think of asthma, you probably think of classic asthma. This form of asthma can cause:
However, the only symptom of CVA may be a persistent, dry cough that lasts several days to weeks. You don’t have mucus in your lungs, so you don’t make wet, productive, or rattling sounds — instead, you might have bouts of hacking (short, dry coughing). However, if cough-variant asthma goes untreated, it will likely worsen and become more like classic asthma.
Of all the causes of coughing, CVA is one of the most common worldwide. In the United States, 10 percent to 20 percent of people have a chronic cough that may prompt them to seek help from their doctor.
Outside of asthma, several other conditions may cause chronic cough symptoms:
A combination of the above conditions can also cause chronic cough symptoms.
Doctors and researchers aren’t sure exactly what causes CVA, but there are a few potential culprits. Certain asthma triggers and medications can affect your airways, resulting in the characteristic dry cough.
Symptoms of cough-variant asthma tend to change with the seasons, suggesting that CVA may be an atopic condition. Atopy is “the genetic tendency to develop allergic diseases,” including asthma, according to the American Academy of Allergy, Asthma & Immunology. Atopy is sometimes referred to as an “atopic triad” consisting of eczema, allergies, and asthma. People can have some or all of these conditions.
Those with atopic conditions are more likely to develop responses to allergens (substances that set off an allergic response). Studies show that 40 percent to 80 percent of people with CVA also have atopy and react to allergens that are often carried in the air. Common environmental allergens include pollen, mold, and dust, which can cause inflammation and constriction (narrowing) of the bronchi (airways).
All medications come with side effects, and beta-blockers are no different. Beta-blockers help relax your blood vessels to treat heart disease, high blood pressure, and migraines. However, beta-blockers can also cause your airways to constrict, leading to cough symptoms.
CVA may be caused by other classic asthma triggers. Take note of when your cough begins and ends. For example, does it happen early in the morning, at night, or during exercise?
Other common triggers and irritants that may worsen your cough symptoms include:
Once you learn your CVA triggers, you can take steps to avoid or be prepared to handle them. For example, if you plan on hiking on a spring day and pollen or exercise triggers your cough, it may be a good idea to treat your allergies and bring an emergency or rescue inhaler.
Learn about other ways to prevent exercise-induced asthma attacks.
A persistent cough is the only symptom of cough-variant asthma, making it challenging to diagnose. Your doctor will ask about your medical history and symptoms to rule out any other causes of chronic cough. They’ll also likely perform tests to check lung function and diagnose classic asthma.
One of these tests is spirometry, a pulmonary function test that measures how much air you’re able to breathe in and out. Interestingly, many people with CVA have normal test results, meaning their ability to breathe isn’t affected.
Your doctor may also perform a methacholine challenge test to measure how reactive your airways are. Methacholine is a drug that causes your airways to constrict — the more sensitive your airways are, the more they will constrict. They can also measure how well you respond to albuterol after the methacholine challenge. People with CVA generally have some airway reactivity, but it’s not as severe as in those with classic asthma.
Other challenge tests can be used to see if they trigger CVA symptoms. For example, if your cough tends to get worse when you work out, your doctor may have you exercise so they can observe your symptoms.
Cough-variant asthma typically responds to similar medications as classic asthma, so your doctor will likely consider those for treatment. These drugs include medications taken with an inhaler and aerochamber and/or pills taken by mouth. Depending on how severe your CVA is, you may be prescribed a long-term maintenance medication or a rescue medication.
Inhaled corticosteroids (also known as inhaled steroids) are often the first choice for treating CVA. These medications help reduce airway inflammation, swelling, and airway reactivity to ease your cough and prevent asthma coughing attacks. Inhaled steroids are taken daily using an inhaler with aerochamber and can be used long term to manage CVA. Examples include:
Research shows that inhaled steroids are the most effective treatment for preventing CVA from worsening and progressing to classic asthma. You may need to increase your dose if the starting dose isn’t helpful enough and if you’re still having coughing attacks. A handful of studies have found that among adults who don’t take inhaled steroids to treat their CVA, between 30 percent and 40 percent eventually develop classic asthma, according to the journal Current Respiratory Medicine Reviews.
If inhaled steroids aren’t as effective and your cough continues, you may be prescribed an additional maintenance medication to help calm inflammation and open your airways.
Long-acting beta-agonists (LABAs) are bronchodilators that relax your airway muscles, helping you breathe easier. LABAs are often combined with inhaled steroids to help treat symptoms associated with CVA in a single inhaler.
Examples of combination medications include:
Your body releases leukotrienes when you come in contact with an allergen. Leukotrienes are responsible for causing many asthma symptoms, including cough. Maintenance asthma medications called leukotriene modifiers can either stop your body from making more of these chemicals or block their function.
Examples of leukotriene modifiers include:
For less frequent CVA symptoms that don’t affect your daily life and activities, your doctor may recommend using rescue medication only as needed rather than long-term daily maintenance therapy. Rescue medications can help treat your asthma cough, especially if it’s triggered only in specific situations.
Short-acting beta-2 agonists (SABAs) are bronchodilators that work fast to relax your airways and open them up. These drugs are to be used as an emergency treatment to stop sudden or severe asthma symptoms.
SABAs can also be used before exercising or going out into the cold to help prevent CVA symptoms related to those situations. However, these drugs aren’t meant for daily use. If you find yourself using your rescue inhaler frequently, talk to your doctor about maintenance therapy.
Learn more about how to be prepared for asthma attacks and recognize when it’s an emergency.
If you or your child experiences a persistent cough or one that worsens during certain activities, talk to your doctor. They can help rule out other causes and diagnose cough-variant asthma to optimize your asthma treatment plan. By controlling your CVA as soon as possible, you can better manage your condition and prevent it from progressing to classic asthma.
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