One of my daughters was diagnosed with cough variant asthma. We had never heard of such a term, so we spent some time doing the research. It turns out that most people who are diagnosed with this form of asthma are also children with childhood asthma, like our daughter.
The main symptom of cough variant asthma is a dry, non-productive cough. This cough may worsen at night, with exercise or when exposed to asthma triggers. Most people with cough variant asthma do not exhibit any of the "classic" asthma symptoms, like wheezing or shortness of breath. This type of asthma may lead to "classic" symptoms down the line.
Cough variant asthma can be very difficult to diagnose because it mimicks many other things. Even a cold or sinus infection could present with the same symptoms. If your child's doctor thinks they may have cough variant asthma there are several tests they may want to run.
This exam will check the basics and may catch other reasons for the cough. A physical exam on a child may include (but is not limited to): listening to the lungs, assessment of overall appearance, height and weight, family history, blood pressure along with any other basics the doctor feels may be prudent. If your child has not had a recent Well Check then expect some form of a physical exam.
Pulse Oxygen Screening
This basic test involves an electrode being placed over your child's finger to measure the amount of oxygen circulating in the blood as a percentage. If you have an infant then the test may also be done on the toe. The test takes a few seconds and a percentage of oxygen saturation will show up on the device. This percentage lets the doctor know how well your child's lungs are functioning. A reading of 100 percent is the score you want to have. The lower the percentage, the more likely there is to be an issue. Be sure to remove any fingernail polish for this test to insure an accurate reading.
During a chest X-ray two images will be taken of you child's lungs: one is usually a front view and one is a side view. This allows your doctor a good look at what is going on inside the lungs in order to rule out things like pneumonia, bronchitis, pleurisy, tumors or other factors. Sometimes, in severe asthma, the chest X-ray can also show damage to the lung tissue if the asthma has been untreated.
Spirometry is a test that measures the amount of air you can inhale, exhale and how quickly you can empty your lungs. This test is a good indicator of lung function but it can be very hard for a child under 5 to do this test accurately, so they are generally not used in children of that age.
During this test your child will take a deep breath through a mouthpiece and then push all of the air out of the lungs as hard and fast as they can. This data is then used to compare to normal levels and determine whether your child is having issues breathing. Sometimes a fast-acting asthma medication like albuterol may be given after the initial test and then the test is repeated. This lets doctors know if the asthma medication opens the airway and resolves or improves breathing.
Methacholine Challenge Test
This test is a last resort in most cases and is used only when the other tests do not identify asthma and asthma is still suspected. During this test the child inhales a mist of methacholine that is made to induce airway spasm and narrowing.
The dose of the mist will be gradually increased until the lung function drops by 20 percent. Once that is noted, a medication to counteract the airway spasm and narrowing is always given. The amount of the methacholine needed to induce symptoms indicates whether asthma is present. In children with asthma, it will not take much of the methacholine mist to decrease the lung function by 20 percent.
Once your child has been diagnosed with cough variant asthma, it will be treated just like regular asthma is treated. Your child's physician may prescribe a long-acting inhaler (like Flovent or QVAR) to use daily to prevent attacks. They may also provide an albuterol inhaler (like ProAir or Ventolin) for quick relief in the case of an immediate attack. If allergies are thought to be a factor in triggering your child's symptoms, medications like Zyrtec, Singulair or others may also be used.
The main problem we have come across with cough variant asthma is the lack of education. Especially in a classroom setting, it can be very hard for a teacher to distinguish this type of cough from the run-of-the-mill type of cough they hear in the classroom every day. It is important to inform your child's teacher about this potential issue and empower your child to ask for help when they need it.
In our daughter's instance, she starts with symptoms of cough variant asthma and if she is not treated it progresses very rapidly into full-blown wheezing. Unfortunately, by the time she is wheezing she won't be able to find someone to help. Again, this is when it becomes so important to keep caregivers informed and paying attention.
If you think your child may have this form of asthma, talk with their pediatrician. They may want to do one or more of these tests to determine what is going on. When it comes to lung function it is always better to get things checked.
Published On: October 23, 2014