Diseases & Conditions
A chronic inﬂammatory disease characterized by airways that have become sensitive to substances that trigger an allergic reaction: First, the lining of the airways become swollen and inﬂamed, the muscles that surround the airways tighten, and mucus production increases. All of these factors cause the airways to narrow, making it hard for the child to breathe air out of the lungs.
Asthma affects more than 4.8 million children in the United States, making it the most common serious and chronic disease among children; it is the third most common cause of childhood hospitalizations under the age of 15. Alarmingly, asthma cases and asthma deaths have been increasing. From 1979 to 1996, asthma deaths have risen 120 percent from 2,598 to 5,667. Hospitalizations for asthma have increased 256 percent from 1979 to 1996, to 474,100 people annually.
Although any child may develop asthma, it most commonly occurs in children by the age of ﬁve, a child with a family history of asthma, children with other allergies, or children exposed to secondhand tobacco smoke. Asthma is 26 percent more common in African-American children than in Caucasian children, and African-American children with asthma generally experience more severe disability from asthma and have more frequent hospitalizations.
The exact cause of asthma is not known, but experts believe it may be inherited; however, asthma also involves many other environmental, infectious, and chemical factors. Each child has different triggers that cause the asthma to worsen. Some children have exercise-induced asthma, which is triggered during or shortly after exercise.
The changes that occur in asthma are believed to happen in two phases: An immediate response to the trigger leads to swelling and narrowing of the airways, making it hard for the child to breathe. A later response, which can happen four to eight hours after the initial exposure to the allergen, leads to further inﬂammation of the airways and obstruction of airﬂow.
Each child may experience symptoms differently. It is important to remember that some children do not exhibit the characteristic wheeze of asthma— they may only cough. The cough may be either constant or intermittent, there may be wheezing (a whistling sound that may be heard while your child is breathing), or a child may have trouble breathing or experience shortness of breath while playing or exercising. Some children may complain that their chests hurt or feel tight. Other symptoms include fatigue, night-time cough, and noisy breathing.
Because the symptoms of asthma may resemble other problems or medical conditions, a physician or respiratory specialist should make the diagnosis.
To diagnose asthma and distinguish it from other lung disorders, physicians rely on a combination of medical history, physical examination, and laboratory tests, which may include
• spirometry—the evaluation of lung function— one of the simplest, most common pulmonary function tests
• peak ﬂow monitor—a device that measures the amount of air a child can blow out of the lungs. This is very important in evaluating how well or how poorly the disease is being controlled.
• chest X ray (to rule out PNEUMONIA)
• blood tests to analyze the amount of carbon dioxide and oxygen in the blood (less common unless child is hospitalized)
• allergy tests
• pulse oximetry to analyze the oxygen content of the blood