What is wheezing?
Wheezing refers to a musical breathing sound made when air flowing in and out of the lungs is temporarily impaired or blocked. The wheezing sound is produced as air is forced through airways which have become narrowed and it is this narrowing which leads to breathing difficulty.
Why does wheezing happen?
Children who experience wheezing have airways which are sensitive to specific triggers. Once exposed to these triggers, the airways or breathing tubes become irritated and three events occur: 1) the muscles of the airways constrict and the airway becomes narrow, 2) an inflammatory reaction or swelling occurs in the walls of the airways, and 3) thick mucus is produced in the airways. Together, these three events cause an obstruction in the airways. It is the flow of air through these narrowed airways which produces the sound known as wheezing and the conditions known as bronchiolitis, reactive airway disease and asthma. There are many different triggers, which can cause an infant, child, or adolescent to wheeze including allergens (pollens, mold spores, pets, and dust mites) irritants (cigarette smoke, paint, cleaning fumes and pollutants), viral respiratory infections (colds), exercise, cold air, emotions and stress.
What is Bronchiolitis?
Bronchiolitis refers to wheezing associated with an upper or lower respiratory tract viral illness (i.e. cold). Many infants and toddlers will have one or two isolated episodes of wheezing, usually during the fall and winter months, which are associated with colds. These isolated episodes are termed bronchiolitis or inflammation of the small airways (not bronchitis, a disease of adults, which is inflammation of the large airways). While any cold virus can cause a susceptible child to wheeze, a specific few (RSV, Parainfluenza) will cause large numbers of infants and toddlers to wheeze
What is Reactive Airway Disease?
Of those children who have had an episode of bronchiolitis, some will go on to have recurrent wheezing episodes associated with any cold virus. The term reactive airway disease (RAD) is used to describe those infants and toddlers who have multiple episodes (i.e. more than two per year) of wheezing associated with colds. As a matter of fact, the most common trigger for wheezing episodes in infants and toddlers are respiratory tract viral illnesses (i.e. colds) and the chances are very good that these patients will outgrow this condition by the early school years.
What is Asthma?
Asthma is defined as multiple wheezing episodes associated with multiple triggers. Unlike RAD, asthma is more commonly associated with exposure to allergens (pollen, mold spores, pets, and dust mites) and irritants, (including cigarette smoke, pollutants, exercise, cold air, stress and emotions) although colds or viruses can also trigger an asthma attack. Most children diagnosed with asthma will outgrow their disease by age 5 and still others by age 10. Those who do not outgrow asthma by age 10 are likely to have it persist into adulthood.
It is best to view bronchiolitis, reactive airway disease, and asthma as related, but separate conditions. Real life experience has taught us that many children will overlap between these three conditions and wheeze when exposed to both cold viruses and allergens. Moreover, wheezing patterns may differ from season to season and year to year. The terms reactive airway disease and asthma are often used interchangeably among health care providers.
It is difficult to predict which children will develop reactive airway disease or asthma. However, there are two groups of children whom are predisposed to having sensitive airways: those with a family history of wheezing or asthma and those exposed to second hand cigarette smoke, especially those children whose parents smoke at home and in the car.
What are other symptoms associated with wheezing?
The main symptoms of any wheezing episode include shortness of breath, tightness in the chest and/or recurrent cough. Symptoms vary among patients. In fact, some patients do not actually wheeze; so called “cough equivalent wheezing” may be seen with persistent cough as the first and only symptom, especially for young children and especially at night. If the wheezing is triggered by a virus, the child will also experience the typical “cold” symptoms of runny nose, congestion and possibly fever. If the wheezing is triggered by an allergen the child may not have symptoms other than wheezing and shortness of breath.
How is Reactive Airway Disease or Asthma treated?
There are two aspects to treating a patient with reactive airway disease: 1) Treatment of wheezing once it has already started and 2) prevention of wheezing episodes.
The ways in which we administer medication to children include:
- Aerosol: the medication is placed in a cup, which is connected to an aerosol machine, and the patient either wears a mask over the nose and mouth or breathes through a tube. Although efficient, this is the most cumbersome and inconvenient method of giving medicine, as it requires the machine and an electrical source or battery.
- Inhaler: Many medications can be given as an inhaler, also known as a “puffer.” While actually using an inhaler by itself requires a fair amount of coordination between hand, mouth and breathing, there are a number of spacer (or extender) devices available which allow us to use an inhaler in a child beginning as young as nine months.
- Pills and Liquids: Occasionally, your child may be asked to take a medication by mouth.
The types of medications used to treat RAD and asthma include:
- Bronchodilators (such as Albuterol, Ventolin or ProAir) which act to open narrowed airways; these medications are most useful during acute episodes of wheezing symptoms.
- Anti-inflammatory agents, like inhaled steroids (such as Flovent or Pulmicort), which interrupt the development of airway swelling, these agents act during acute wheezing episodes and are also useful for prevention of wheezing exacerbations.
- Leukotriene receptor inhibitors (such as Singulair), which blocks the effects of leukotrienes, on cells. The release of leukotrienes is the body’s first reaction to a foreign substance (such as a virus or allergen) which then leads to lung inflammation and muscle constriction. Therefore these medications help prevent an asthma attack and can help control asthma symptoms for a full 24 hours.
- For individuals with chronic asthma, there are also medications that combine bronchodilators and steroids into one inhaler (such as Symbicort or Advair).
In general, the goals of Reactive Airway Disease and Asthma management include:
- Maintenance of normal activity levels, including exercise,
- Prevention of chronic and troublesome symptoms such as coughing,
- Prevention of recurrent episodes of wheezing,
- And avoidance of adverse effects from medication.
Prevention refers to the prevention of acute episodes of wheezing. Such prevention involves medications, and often more importantly, environmental controls to reduce exposure to airway irritants and allergens. To help control common asthma triggers, it is essential that patients with asthma not smoke tobacco and that exposure to passive smoke be eliminated.
While asthma and reactive airway disease are chronic diseases of the lungs and airways without a specific cure, the primary symptoms and the wheezing episodes are treatable, and more importantly, preventable. As your child’s health care providers, we will work closely with you to develop a treatment and management plan, which works well for your child, family and school. Our goal is to have our patients with reactive airway disease and asthma lead as normal a life as possible with minimal interference from either wheezing or the medications used to help prevent the wheezing symptoms.