Understanding Asthma
By Judy Voynow, MD and 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.

What are the symptoms of 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.)

How severe is the 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
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 an associate professor of pediatrics at Duke. Dennis Clements, MD, PhD, is interim chair of the Department of Pediatrics at Duke University Medical Center. For more information, visit: www.dukehealth.org

The information presented on this site is intended solely as a general educational aid, and is neither medical nor healthcare advice for any individual problem, nor a substitute for medical or other professional advice and services from a qualified healthcare provider familiar with your unique circumstances. Always seek the advice of your physician or other qualified healthcare professional regarding any medical condition and before starting any new treatment.