Do you have a dry, hacking cough that just won't go away? Does it seem to get worse after you exercise, laugh, or cry? It's not uncommon to have a chronic cough and asthma. Or you might have what doctors call cough-variant asthma -- especially if you coughed mostly during the night at first but now cough constantly throughout the day.
So, what is cough-variant asthma? For starters, it's a type of asthma that's often difficult to diagnose, said Lauren Fine, MD, an allergist/immunologist and assistant professor of medicine at the University of Miami Miller School of Medicine. The issue, she explained, is that the cough may be your only symptom. You typically won't have other common symptoms of asthma, like wheezing, shortness of breath, and chest tightness.
More Than Just a Cold
“Cough-variant asthma is not something like a cold that you get and goes away,” Dr. Fine said. Your cough must last at least six to eight weeks before it’s considered chronic. If you have a chronic cough that's dry, meaning there's no phlegm or mucus, your doctor may order a lung function test to determine whether you could have cough-variant asthma.
If your lung function test is inconclusive, you may need to have a methacholine challenge test to see how your lungs are working. In this test, you're given increasing doses of the drug methacholine to inhale and then your doctor tests your lung function. If you have asthma, methacholine can trigger wheezing when it's inhaled. People with normal long function have little or no reaction to this drug.
“Cough-variant asthma is not something like a cold that you get and goes away.”Lauren Fine, MD
Anyone is susceptible to cough-variant asthma. Of those who see their doctor for a chronic cough, about 25 percent may be suffering from cough-variant asthma.
Why do some people get cough-variant asthma? That’s a good question, Fine said. “We don’t have an answer why some people get cough-variant asthma versus asthma that has typical symptoms.” Triggers for cough-variant asthma are the same as the ones for other types of asthma: exposure to dust, exercise, and low temperatures.
Sometimes, Fine said, the best way to diagnose cough-variant asthma is to try taking asthma medications. “If the cough gets better with the medication, you can make the assumption that it’s cough-variant asthma," she said. "If you treat them for asthma and they don’t get better, it’s not cough-variant asthma and you look for another cause.”
Cough-variant asthma is common in young children, which makes it even more difficult to diagnose. “Kids under 4 years of age may be too young to do the breathing test,” Fine explained. “It takes the intelligence of a 5-year-old to understand what we’re asking them to do.”
Asthma Medications May Improve Your Lung Function
Cough-variant asthma is treated the same way as other types of asthma. The severity and frequency of your symptoms help determine what medications are best. “If symptoms are pretty mild, you would start with montelukast (Singulair), a long-term control medicine,” Fine said. It helps block the chain reaction that can cause your airways to become swollen and inflamed.
The bronchodilator albuterol (Proventil) also can help prevent and treat symptoms of cough-variant asthma. “The main goal of treatment is to help ease discomfort,” Fine said. “The inhaler albuterol should do that.” Some people may need a more potent steroid for asthma, such as oral prednisone, for their cough to disappear completely.
If you think your constant hacking, dry cough might be cough-variant asthma, ask your doctor whether you should be tested to determine the best treatment for you. As with any type of asthma, it’s important that you stay healthy by eating a nutritious diet, getting regular exercise, and taking your medications as prescribed.