Published: May 3, 2007
Updated: Dec. 14, 2009
By Dennis Clements, MD, PhD
“My child coughs for weeks after every cold. What should I do?”
It’s one of the most common questions I hear from parents—and one with a wide range of possible answers. Chronic cough can be due to anything from persistent fluid in the middle ear to gastroesophageal reflux to tic syndromes or postnasal drip from allergies and colds. More and more often, though, we’re seeing chronic coughs caused by asthma—a serious illness that has become considerably more common over the past 25 years.
Asthma is an enormous public health problem in our country today, affecting over four million children under age 18. In the mid-1990s, asthma exacerbations were responsible for approximately 500,000 hospitalizations per year, 1.8 million emergency room visits, and around 5 million physician office visits. The indirect costs of missed school days and work days due to asthma exacerbations were estimated at over 2 billion dollars in 1998.
Asthma doesn’t just cause problems for society, of course—it can be a troublesome and sometimes scary illness for children and their parents, as well. Fortunately, pediatricians can do more than ever to help children manage asthma, as Duke pediatric pulmonologist Dr. Judy Voynow explains below.
--Dennis Clements, MD, PhD
Asthma is a chronic respiratory disease that can be triggered by viral infections, allergen exposure, exercise, tobacco smoke, air pollutants, and even changes in the weather. In patients with asthma, these “triggers” activate the body’s immune system; white blood cells enter the airway and release mediators that cause inflammation. This inflammatory response causes smooth muscles in the airway to contract (bronchospasm), increases mucus production, and causes the airway lining to swell (airway edema). These changes all contribute to the airway obstruction which we know as asthma.
The most common symptoms associated with asthma in children are cough, wheezing (a high-pitched noise during exhalation), increased shortness of breath, and/or the sensation of chest tightness or pain. Children with these symptoms should be evaluated by their physician, as the same symptoms may also be caused by other lung diseases such as cystic fibrosis, viral bronchiolitis, and other disorders of the lung, heart, or gastrointestinal tract. (It is important to note that bronchitis in children may be an exacerbation of asthma and, if it is, it should be treated like asthma.)
Asthma is classified as mild, moderate, or severe depending on the severity of a child’s symptoms. These definitions help determine what treatment is necessary.
Mild asthma is defined as asthma symptoms that occur less than three to six times per week. Moderately severe asthma is defined as asthma symptoms that occur daily or nighttime symptoms more than once per week. Severe asthma is characterized by continual symptoms and frequent nighttime symptoms.
While symptoms can be a useful sign that asthma is acting up, older school-age children can also monitor their airway obstruction by measuring peak expiratory flow through a peak flow meter at home. Each child records their peak flow number at the same time of day and at the same time in relation to when they take their medications. They establish their personal best peak flow. If their peak flow is between their personal best and 80 percent of their personal best, this is the “green zone” and they continue their current asthma regimen. If their peak flow is between 80 percent and 60 percent of their personal best, they are in the “yellow zone” of lung function and will require extra doses of rescue medication (short acting beta-2 agonists) and doubling of their inhaled glucocorticoids. Finally, patients with peak flows less than 50 percent of personal best require evaluation by their doctor.
Some children with asthma may be symptom-free between asthma attacks. However, asthma is a chronic disease that does not go away--even when they have no symptoms, children need maintenance therapy to stay healthy.
Asthma therapy is divided into two categories -- “maintenance” (or long-term) therapy and “quick relief” therapy.
Maintenance therapy reduces inflammation, which decreases the risk of bronchospasm and helps to diminish airway swelling and mucus production when asthma is triggered. Anti-inflammatory maintenance therapy includes inhaled glucocorticoids (Pulmicort or Flovent), an effective broad spectrum anti-inflammatory medicine; or an oral leukotriene modifier (Montelukast or Singulair), a once-a-day medication that blocks an inflammatory receptor. Other maintenance therapies include a combination of an inhaled glucocorticoid and a long-acting beta-2 agonist that reduces bronchospasm (such as Advair) or oral theophylline.
For children with mild persistent asthma, either a low-dose inhaled glucocorticoid or leukotriene modifier are used daily to keep symptoms under control. For moderately severe asthma, the inhaled glucocorticoid dose may be increased to the medium range, and used along with a second maintenance medicine such as a leukotriene modifier and/or a long-acting beta-2 agonist. For severe asthma, inhaled glucocorticoids are used at the highest end of the dosage range, in combination with a leukotriene modifier and a long-acting bronchodilator--either a beta-2 agonist and/or theophylline.
For “quick relief” or rescue medication, which is used during asthma attacks, the most commonly used drugs are the inhaled short-acting beta-2 agonists (such as Albuterol). Inhaled medications may be administered through a nebulizer, through hand-held inhalers with spacers, or through special devices that don’t require spacers. It is important that a trained professional evaluate whether the device is working for your child and effectively delivering medication to the lungs.
During severe exacerbations of asthma, the most potent therapy for outpatients is oral glucocorticoids. Although glucocorticoids are very effective to resolve asthma symptoms, they should only be used for a limited time as regular long-term use can cause unwanted side effects. Antibiotics are not effective therapy for asthma except in the setting of a bacterial infection such as an ear infection, sinusitis, or pneumonia.
It is important that families seek the advice of specialists if asthma is severe (requiring hospitalizations) or if the child fails to respond to therapy. Children with difficult-to-control asthma should also be evaluated for conditions that can exacerbate asthma, including allergic rhinitis, sinusitis, and gastroesophageal reflux.
Although asthma is a challenging problem, it can be managed. Our goal is to help every child with asthma keep their condition well under control so they can grow, develop, and exercise to their potential.
Judy Voynow, MD, is a professor of pediatrics at Duke.
Dennis Clements, MD, PhD, is the chief of primary care pediatrics atDuke Children's Hospital.