Asthma

ASTHMA
Resource Sites
· http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Asthma
· http://www.mayoclinic.com/health/asthma/DS00021/DSECTION=4
· http://www.healthinsite.gov.au/topics/Asthma
· http://www.mayoclinic.com/health/asthma/AS00003
Asthma is a common condition which affects the small air passages (bronchi) of the lungs. These passages become swollen and inflamed, and this leads to the production of mucus (fluid). During an asthma attack, these small airways become narrow. This reduces the flow of air in and out of the lungs. This may lead to wheezing, coughing and difficulty with breathing. Not all children who have asthma will wheeze or cough.Asthma attacks can be controlledAn asthma attack can be controlled with medication. Asthma is an illness that comes and goes at different times. Most children with asthma will have an occasional attack, while a few will have symptoms every day.Asthma is triggered by different thingsAsthma tends to run in families. It is also associated with other conditions such as eczema, hayfever and allergies. Asthma is triggered by different things for different children. Some common triggers are:
Colds
Changes in the weather
Cigarette smoke
Dust and dust mites
Pollen
Some animals.
Coughing is a symptomWheezing and coughing are common symptoms of asthma. Coughing is most likely to happen:
At night
During the early hours of the morning
In cool weather
During exercise.
Things to remember
The common signs of asthma are coughing and wheezing.
Different triggers bring on asthma in different people.
Asthma can be controlled with reliever and preventer medication.
See your doctor if your child does not respond to reliever medication.
Find out more about asthma and its treatment to help you feel more confident to look after your child.

People with asthma are sensitive to different triggers in their environment. Triggers, or allergens, cause inflammation or swelling in your airways and make your asthma worse. An allergen is any substance that can bring on an allergic reaction. An allergy is your body’s response to a substance that is normally harmless to most people. If you are allergic to something, then eating it, breathing it or touching it can bring on an allergic reaction. Most people with asthma are atopic; that is, they have a general tendency to develop allergic diseases. More than 80 per cent of people with asthma find their symptoms get worse when they are exposed to allergens. Managing your asthma includes identifying the triggers that make your symptoms worse and doing all you can to avoid exposure to those triggers.Many allergens are carried in dust
Minute particles of dust float around in the air you breathe. Depending on the environment you’re in (such as city or country, home or work) and the time of year (such as spring), these dust particles can contain allergens such as:
House dust mite droppings
Skin, scales, fur particles (called ‘dander’) from animals
Insect debris
Food dust
Pollens
Moulds.
Other types of triggers
It’s not just allergens that can trigger asthma symptoms. Other common triggers include:
Respiratory infections (common cold)
Cold, dry air
Some medications
Exercise
Cigarette smoke
Wood fire smoke
Perfumes
Paint
Chemicals
Gases.
Identifying your triggers
It is important to know which particular triggers bring on your asthma symptoms. This can be easy with triggers you can see, such as cigarette smoke or animals. However, sometimes it can be tricky. Try to keep a diary of the times and situations when your asthma is worse. Some general tips to help you in your investigations include:
If you have asthma all year round, with symptoms worsening a little in autumn, you may be allergic to house dust mite droppings.
If your asthma symptoms are worse in spring and early summer, you may be allergic to pollens. Your symptoms will depend on what type of pollen you are allergic to.
Skin prick testing
Allergy testing can help to pinpoint your allergens. The doctor puts small dabs of different allergen solutions, such as pollen extract, along your arm. Then the doctor slightly pricks the skin underneath with a needle. If the skin swells or develops a welt, you are allergic to that substance. Blood tests are available too. However, these skin and blood tests are not conclusive. Just because your skin and blood reacts to the allergen, doesn’t mean your lungs will too. Think of these tests as a helpful starting point. Other types of allergic reactions
When a person with asthma is exposed to allergens, their asthma gets worse. Depending on the allergen and where it enters your body, you may experience different symptoms.Other allergic reactions may include:
Rhinitis (or hay fever) – sneezing, blocked and runny nose, itchy eyes and throat.
Eczema – dry, red, itchy skin.
Hives – skin rashes.
Investigation (Diagnosis)
Asthma symptoms raise a red flag, but firm diagnosis of asthma is more complicated.
If you have bouts of wheezing, coughing and shortness of breath, your doctor may suspect asthma. But symptoms alone aren't enough for him or her to arrive at a diagnosis of asthma. Your doctor will also need to understand how, when and where your symptoms occur. After gathering that information, your doctor will probably recommend a lung function test, followed by a trial of medication that helps people with asthma breathe more easily. If the medication works, you probably do have asthma.
Diagnosis of asthma: Medical history holds clues
During an assessment for asthma, your doctor may ask a series of questions about your symptoms. It's best if you can provide detailed answers. Here are some questions that explore symptoms of asthma and help with the diagnosis of asthma.
During the past 12 months, have you:
§ Had a sudden, severe episode or recurrent episodes of wheezing, coughing or shortness of breath?
§ Had colds that "go to the chest" or take more than 10 days to get over?
§ Had wheezing, coughing or shortness of breath only when you're in certain places, such as your home or workplace, or outdoors?
§ Had wheezing, coughing or shortness of breath when exposed to certain substances such as pollen, tobacco smoke, cat dander or perfume?
§ Used any medications that help you breathe better? If so, how often did you use them and how well did they work?
In the past four weeks, have you had wheezing, coughing or shortness of breath:
§ At night that has awakened you?
§ In the early morning?
§ After running, moderate exercise or other physical activity?
A "yes" answer to any of these questions may suggest that you have asthma.
Because the tendency to develop asthma may run in families, be prepared to talk about your family's health history. Your childhood illnesses and exposure to certain substances are also of interest. These questions may include:
§ Have your parents, brothers, sisters or children ever been diagnosed with asthma, allergies, sinusitis or nasal growths (polyps)?
§ Have you ever been diagnosed with an allergic condition such as hay fever or eczema?
§ As a young child, did you ever develop pneumonia?
§ As a young child, were you exposed to second-hand smoke from your parents or other family members?
Physical exam: Detecting signs of asthma
A physical examination of your upper respiratory tract, chest and skin generally follows the history. Using a nasal speculum, your doctor may look inside your nose for signs of allergic disease such as increased nasal secretions, swelling or polyps. These signs may suggest that allergies are responsible for triggering your suspected asthma.
Your doctor also may use a stethoscope to listen to the sounds your lungs make as you breathe. Wheezing sounds indicate one of the main signs of asthma: obstructed airways.
Finally, your doctor may examine your skin for signs of allergic conditions such as eczema or hives, which are often associated with asthma
answer to any of these questions may suggest that you have asthma.
Because the tendency to develop asthma may run in families, be prepared to talk about your family's health history. Your childhood illnesses and exposure to certain substances are also of interest. These questions may include:
§ Have your parents, brothers, sisters or children ever been diagnosed with asthma, allergies, sinusitis or nasal growths (polyps)?
§ Have you ever been diagnosed with an allergic condition such as hay fever or eczema?
§ As a young child, did you ever develop pneumonia?
§ As a young child, were you exposed to second-hand smoke from your parents or other family members?
MORE ON THIS TOPIC
§ Asthma
Lung function tests: Measurements of breathing to assess possible asthma
Although your symptoms, medical history and physical examination may suggest that you have asthma, one final step, a lung (pulmonary) function test, is required to confirm an asthma diagnosis. A pulmonary function test may include one or more of the following tests.
SpirometryThis noninvasive test, which takes 10 to 15 minutes and measures how well you breathe, is the preferred test for diagnosing asthma. During spirometry, you take deep breaths and forcefully exhale into a hose connected to a machine called a spirometer.
Spirometry measures three values that are important in diagnosing asthma:
§ Vital capacity, which is the maximum amount of air that you can inhale and exhale
§ Peak expiratory flow rate, also known as the peak flow rate, which is the maximum flow rate you can generate during a forced exhalation
§ Forced expiratory volume, which is the maximum amount of air you can exhale in one second
If certain key measurements are below normal for a person your age, it may be a sign that your airways are obstructed. Your doctor may ask you to inhale a bronchodilator drug used in asthma treatment to open obstructed air passages. Then you retake the spirometry test. If your measurements improve significantly, it's likely that you have asthma.
Spirometry isn't foolproof. Your doctor may still suspect that you have asthma even if your initial spirometry measurements are normal. If so, he or she may recommend the next test — a challenge test.
Challenge testDuring this test, you deliberately trigger airway obstruction and asthma symptoms by inhaling an airway-constricting chemical or taking several breaths of cold air. If you appear to have exercise-induced asthma, you may bring on symptoms by doing vigorous physical activity.
After inhaling the symptom-producing substance or engaging in physical activity, you retake the spirometry test. If your spirometry measurements are still normal, it's likely that you don't have asthma. But if your measurements have fallen significantly, it may be an indication that you have asthma.
Peak expiratory flowThis test, an alternative to spirometry, also measures how well you breathe. What you do is exhale forcefully into a peak flow meter, a small, hand-held device that measures the rate at which you can force air out of your lungs.
Although peak expiratory flow is less accurate than spirometry in measuring airway obstruction, it can still play a role in asthma diagnosis. If your spirometry and challenge tests are normal but your doctor still suspects asthma, he or she may send you home with a peak flow meter and a trial prescription for asthma medications.
Over a six- to eight-week period, you record your peak flow readings before and after taking your medications. If your readings improve significantly, it may be the evidence your doctor needs to make an asthma diagnosis.
Additional tests: Ruling out conditions other than asthma
Your doctor may suspect that you have a condition other than or in addition to asthma. Possibilities include chronic obstructive pulmonary disease (COPD), pneumonia, bronchitis, pulmonary embolism, panic disorder and heart failure, all of which may mimic asthma. Conditions that often accompany asthma include gastroesophageal reflux disease, hay fever and sinusitis.
If your doctor suspects that you have another condition, he or she may conduct other tests or assessments, such as:
§ Complete blood count
§ Chest and sinus X-rays
§ Computerized tomography (CT) scans
§ Gastroesophageal reflux assessment
§ Sputum induction and examination
Your doctor may also perform allergy tests. Although allergy tests aren't used to diagnose asthma, they can help identify substances that may be causing or worsening your asthma.
MORE ON THIS TOPIC
§ Double trouble: The link between allergies and asthma
§ Allergy skin tests: Identify the sources of your sneezing
Diagnosing asthma in children
When assessing children under age 5, doctors seldom conduct lung function tests because young children usually have trouble following the instructions. Instead, when a child's signs and symptoms, medical history and physical examination suggest asthma, the doctor may prescribe a bronchodilator — a drug that opens the airways. If your child's signs and symptoms improve after using the bronchodilator, an asthma diagnosis is likely.
MORE ON THIS TOPIC
§ Childhood asthma
A new diagnostic approach: Exhaled nitric oxide
Because diagnostic tests such as spirometry aren't always accurate, doctors are looking for better ways to diagnose asthma. One newer approach is to measure a chemical marker of asthma — nitric oxide — in exhaled air. In general, higher levels of nitric oxide correspond with higher degrees of asthma severity.

Prepared by Ji Keon
Note: Abridged version is emailed in a PPT form.