Asthma is a chronic lung disease in which the bronchioles or airways narrow, often in response to a trigger such as exposure to an allergen, exercise, or emotional stress. It affects an average of one out of every 10 children1, and is a leading cause of school absenteeism2 and hospitalizations3 among children.
While there is no known specific cause of asthma, researchers think that it is caused by a combination of environmental and genetic factors. Asthma tends to run in families.
The symptoms of asthma can vary from person to person and they can vary in severity. The most common asthma symptoms are:
• Coughing
• Wheezing- a whistling sound- when exhaling
• Shortness of breath (after exercise or physical exertion)
• Difficulty breathing
• Tightness and pressure in the chest
• Dry cough, especially at night
Symptoms can worsen over hours or even minutes, leading to severe restriction of the airways, this is known as an asthma attack or episode.
While there is no known specific cause of asthma, what all people with asthma have in common is chronic airway inflammation. Their airways are highly sensitive to various triggers. When exposed to a trigger, the lining of their airways becomes inflamed, there is an increase in mucus production that may clog up the airways, and the muscles surrounding the airways tighten in response to the attack, causing them to further narrow. This makes breathing difficult and causes an asthma attack. During an asthma attack, a person may feel like he or she cannot breathe in enough air, but actually he or she has trouble getting the air out of their lungs. The stale air is trapped behind the inflamed, tightened airways leaving little room for new air to be inhaled.
The most accurate way to diagnose asthma is through a lung function test called spirometry, which measures how much air you can breathe in and out, and how fast you can the blow air out. It is difficult to for children under five to do lung function tests so their physician must rely only on their medical history and a physical exam. A young child who has frequent wheezing with colds or respiratory infections is more likely to have asthma if4:
• One or both parents have asthma
• The child has signs of allergies, including the allergic skin condition eczema
• The child has allergic reactions to pollens or other airborne allergens
• The child wheezes even when he or she doesn’t have a cold or other infection
While there is no known cure for asthma, and asthma attacks are not always preventable, it can be managed by avoiding triggers as much as possible, recognizing one’s symptoms or warning signs, taking medications as prescribed, and limiting outdoor activities when the air quality is poor.
The best way to treat asthma is to avoid the allergens or triggers that bring on an asthma attack. Triggers are anything that causes asthma symptoms in a person with asthma, and are different for every person. Irritants and allergens are the main types of triggers, and others include emotional stress, cold air, exercise, respiratory infections, and some foods. Allergens are inhaled substances which cause an allergic reaction such as mold, dust mites, pet dander and saliva, pollen, and cockroach droppings. Most children with asthma also have allergies. Irritants do not cause allergic reaction, but irritate the airways. Irritants include tobacco, wood or candle smoke, strong odors, household cleaners, perfumes and scented soap.
Avoiding triggers is not always possible, and prescription medications are often times necessary. Long-term “controller” medications prevent asthma flare-ups over time and are taken even with no symptoms. These are anti-inflammatory drugs which reduce inflammation, swelling and mucus production in the airways. Quick-relief “rescue” medications or bronchodilators provide immediate relief of symptoms. These medications act quickly to open up constricted airways by relaxing the muscles around the airways. Metered-dose inhalers are the most common way to deliver medications into the lungs, and young children also often use a nebulizer which allows the child with asthma to inhale the medicine using a mouthpiece or a facemask.
Asthma is caused by both environmental and genetic factors and there is no way to predict which children will develop asthma, but studies have identified certain predictors:
• A family history of allergies or asthma
• Diagnosed skin and food allergies
• Prenatal and postnatal exposure to tobacco smoke
• Obesity
• Airway infections at a very young age
• Living in areas with high pollution