Approximately 20 million Americans have asthma. Asthma is a
disease of all ages; in fact, 9 million children under age 18 have
asthma. Asthma is costly
– there are 5 million deaths due to asthma annually and the
total cost of asthma for health care and lost productivity is $16.1
billion annually.
Approximately 20 million Americans have asthma. Asthma is a disease of all ages; in fact, 9 million children under age 18 have asthma. Asthma is costly – there are 5 million deaths due to asthma annually and the total cost of asthma for health care and lost productivity is $16.1 billion annually.
Asthma is a chronic, inflammatory disease of the airways. The asthmatic lungs respond to various stimuli such as allergens, smoke, cold weather, pollution, exercise or aspirin. If untreated, the airways structure changes and loses its normal anatomy and function.
This week, we’ll take a look at the different types of asthma, what the symptoms of the disease are and the different ways it can be diagnosed. Next time, we’ll take a look at the treatment of the disease and tips to prevent asthma attacks.
Types of asthma
There are several types of asthma: allergic asthma, occupational asthma, exercise-induced asthma, aspirin-induced asthma, adult-onset asthma and cough variant asthma.
Allergic asthma
This is the most common type of asthma. In U.S., 10 million people suffer from it, and it usually starts in childhood. The asthma symptoms are due to underlying sensitivity to allergens.
Occupational asthma
The symptoms due to this type of asthma occur at work. Patients develop symptoms due to exposure to chemicals, vapors, aeroallergens and irritants at work. When off work, especially on weekends or days off, they feel better and as they return to work, the symptoms recur.
Exercise-induced
asthma
The symptoms due to this type of asthma develop with exercise, often heavy exercise, such as running. Usually, patients do not experience symptoms with light exercise or at rest.
Aspirin-induced asthma
In this type of asthma, symptoms occur after ingestion of aspirin or products in the aspirin family. I have a patient who has aspirin sensitivity; once, after ingesting an aspirin, she developed severe shortness of breath and had to be taken to the emergency room.
Adult-onset asthma
This type of asthma is not as common as allergic asthma. Some patients experience their asthma symptoms after a bout of bronchitis or pneumonia. The affected individuals have no history childhood asthma.
Cough variant asthma
The only symptom of this type of asthma is cough. Usually there is no shortness of breath or wheezing involved. The affected individuals mostly cough at night.
Symptoms of asthma
Asthma symptoms include shortness of breath, chest tightness, wheezing or cough. The affected individuals may awaken from sleep due to chest tightness or shortness of breath. Frequency and length of symptoms are indicators of asthma severity.
Diagnosis of asthma
Diagnosis of asthma is based on history of illness, physical examination and diagnostic testing.
History: your physician can suspect asthma by history alone. For example, if pollens or pet danders bring asthmatic symptoms, you may have allergic asthma. If taking aspirin causes shortness of breath, you may have aspirin-induced asthma.
Physical examination: During an asthma flare, asthmatics may have audible wheezing sounds. The physician can use a stethoscope to listen to the lungs and hear wheezing or ventilation of air coming into and going out of the airways. Asthmatics may have tightness in the chest during doctors visits as well as poor ventilation. If the asthma is controlled, a regular physical examination may not show any signs of lungs abnormality.
Tools for diagnosing asthma
Chest X- rays: Chest X- ray is not a diagnostic tool, but it may give information on conditions of the lungs. In severe asthma, the lungs appear hyperinflated, meaning increased air in the lungs has caused inflation. Asthmatics have obstruction of larger airways and cannot exhale normally. Chest X- rays can also exclude other lung abnormalities such as pneumonia or bronchitis that may have contributed to the asthma flare.
Peak flow meter: Diabetics need to monitor blood sugar by a device known as glucometer. Patients with high blood pressure need to monitor blood pressure by a device known as sphygmomanometer. Asthmatics need to measure their airway condition with a peak flow meter. This is a small hand-held device that has a mouthpiece and a graded hollow tube with a knob. The patient should take a deep breath, then place the mouth on the mouthpiece and blow hard and fast. As the patient blows into the device, the knob moves and you can read the number along the tube where the knob has stopped. This number is a peak of expiratory flow. In asthmatics, this number is low because there is an obstruction of the airways and not much air can come out with the exhalation. To know if the measurement is reasonable, it should be compared with a chart containing the measurements of normal lungs for various ages. For example, if you are 25 years old male with asthma, you should compare your peak flow measurements with a healthy 25-year-old male.
Spirometry: This is a machine that measures your lung function and diagnoses airway obstruction or asthma. Your allergist measures your lung function initially and periodically thereafter. The spirometry measurements guide your allergist to assess your respiratory condition and to make recommendations on your medication regiments.
Dr. Massoud Mahmoudi is an assistant clinical professor in the division of Allergy and Immunology at the University of California, San Francisco’s Department of Medicine and is in private practice in the South Bay. He is the author of the new book “Allergy Cure!” E-mail him questions at do************@***oo.com.
