Wednesday, February 27, 2008

Childhood Asthma, what you should know about it.

What Is Asthma?

Asthma is a chronic disease of the tubes that carry air to the lungs. These airways become narrow and their linings become swollen, irritated, and inflamed. In patients with asthma, the airways are always irritated and inflamed, even though symptoms are not always present. The degree and severity of airway inflammation varies over time.

Children with asthma can have symptoms start or worsen when they are exposed to many indoor substances such as

• Dust and dust mites

• Cockroaches

• Animals such as cats and dogs

• Molds

• Secondhand cigarette smoke

Children with asthma may also be sensitive to colds and other viral infections, cold air, and particles or chemicals in the air. Ongoing exposures to these substances will not only worsen asthma symptoms, but also continue to aggravate airway inflammation.

Inflammation of the airways causes them to be oversensitive and “twitchy,” often called “hyperreactive.” When the airways are hyperreactive, they can go into spasms, causing blockage and symptoms of wheezing, chest tightness, and shortness of breath.

Who Gets Asthma?

Asthma is a common condition in childhood. In the United States, 10% to 15% of children in grade school have or have had asthma. It can cause a lot of sickness and result in hospital stays and even death. The number of children with asthma is increasing, and the amount of illness due to asthma may also be increasing in some parts of the country. The reasons for these increases are not exactly known; however, outdoor air pollution and increased exposure to allergens are not likely causes.

Recent studies suggest that how often and how early a child is exposed to certain infections and animals can influence the development of asthma. For example, children who come from large families, live with pets, or spend a considerable amount of time in child care in the first year of life are less likely to develop asthma. This early exposure to common allergens may actually protect against the development of asthma.

Studies have also shown that a child’s exposure to infections early in life can determine whether he develops allergies or asthma. Some infections seem to decrease the risk of developing asthma, whereas one infection, respiratory syncytial virus, increases the risk.


How Is Asthma Treated?

Any child who has asthma symptoms more than twice per week should be treated. One of the most important treatments of asthma is to control the underlying inflammation of the airways. This can be done with medications or by avoiding environmental factors that cause or aggravate airway inflammation.

Knowing the causes and triggers for asthma can allow families to reduce or avoid these triggers and reduce ongoing airway inflammation and hyperreactivity. This can reduce the severity and frequency of asthma symptoms and, hopefully, the need for as much asthma medication.


How Is Asthma Diagnosed?

It is often difficult, especially in young children, to be entirely certain that asthma is the diagnosis. After a careful physical examination, your paediatrician will need to ask you specific questions about your child’s health. The information you give your paediatrician will help determine if your child has asthma. Your paediatrician will need information about

• Your child’s symptoms, such as wheezing, coughing, and shortness of breath

• What triggers the symptoms or when the symptoms get worse

• Medications that were tried and if they helped

• Any family history of allergies or asthma

It is very important that your paediatrician test your child’s airway function. One way to do this is with a pulmonary function test using a device called a spirometer. This device measures the amount of air blown out of the lungs over time. Your paediatrician may also want to test your child’s pulmonary function after giving her some asthma medication. This helps confirm that the blockage in the air passages that shows up on pulmonary function tests goes away with treatment.

Some children do not find relief from their symptoms even after using medications. If that is your child, your paediatrician may want to test your child for other conditions that can make asthma worse. These conditions include allergic rhinitis (hayfever), sinusitis (sinus infection), and gastroesophageal reflux disease (the process that causes heartburn).

It is important to remember that asthma is a complicated disease to diagnose, and the results of airway function testing may be normal even if your child has asthma. Also keep in mind that not all children with repeated episodes of wheezing have asthma. Some children are born with small lungs, and their air passages may get blocked by infections. As their lungs grow they no longer wheeze after an infection. This type of wheezing usually occurs in children without a family history of asthma and in children whose mothers smoked during pregnancy.


Non-pharmacological Approaches to Asthma Management

Asthma Triggers

Certain things cause asthma “attacks” or make asthma worse. These are called triggers. Some common asthma triggers are

• Things your child might be allergic to. These are called allergens. (Most children with asthma have allergies, and allergies are a major cause of asthma symptoms.)

- House dust mites

- Animal dander

- Cockroaches

- Mold

- Pollens

• Infections of the airways

- Viral infections of the nose and throat

- Other infections, such as pneumonia or sinus infections

• Irritants in the environment (outside or indoor air you breathe)

- Cigarette and other smoke

- Air pollution

- Cold air, dry air

- Odors, fragrances, volatile organic compounds in sprays, and cleaning products

• Exercise (About 80% of people with asthma develop wheezing, coughing, and a tight feeling in the chest when they exercise.)

• Stress

Be sure to check all of your child’s “environments,” such as school, child care, and relatives’ homes, for exposure to these same things.

Help Your Child Avoid Triggers

While it is impossible to make the place you live in completely allergen- or irritant-free, there are things you can do to reduce your child’s exposure to triggers. The following tips may help.

• Do not smoke or let anyone else smoke in your home or car.

• Reduce exposure to dust mites. The most necessary and effective things to do are to cover your child’s mattress and pillows with special allergy-proof encasings, wash their bedding in hot water every 1 to 2 weeks, remove stuffed toys from the bedroom, and vacuum and dust regularly. Other avoidance measures, which are more difficult or expensive, include reducing the humidity in the house with a dehumidifier or removing carpeting in the bedroom. Bedrooms in basements should not be carpeted.


• If allergic to furry pets, the only truly effective means of reducing exposure to pet allergens is to remove them from the home. If this is not possible, keep them out of your child’s bedroom and consider putting a high-efficiency particulate air (HEPA) filter in their bedroom, removing carpeting, covering mattress and pillows with mite-proof encasings, and washing the animals regularly.

• Reduce cockroach infestation by regularly exterminating, setting roach traps, repairing holes in walls or other entry points, and avoiding leaving exposed food or garbage.

• Mould in homes is often due to excessive moisture indoors, which can result from water damage due to flooding, leaky roofs, leaking pipes, or excessive humidity. Repair any sources of water leakage. Control indoor humidity by using exhaust fans in the bathrooms and kitchen, and adding a dehumidifier in areas with naturally high humidity. Clean existing mould contamination with detergent and water. Sometimes porous materials such as wallboards with mould contamination have to be replaced.

• Pollen exposure can be reduced by using an air conditioner in your child’s bedroom, with the vent closed, and leaving doors and windows closed during high pollen times. (Times vary with allergens, ask your allergist.)

• Reduce indoor irritants by using unscented cleaning products and avoiding mothballs, room deodorizers, or scented candles.

• Check air quality reports in weather forecasts or on the Internet. When the air quality is poor, keep your child indoors and be sure he takes his asthma control medications.

• Decreasing your child’s exposure to triggers will help decrease symptoms as well as the need for asthma medications.


Pharmacologic Management of Asthma

Asthma Medications

The goals of treatment for asthma are to minimize symptoms and allow children to participate in normal physical activities with minimum side effects. It is also important to prevent emergency department visits and hospitalizations due to asthma attacks. Ideally, this means your child should not experience asthma symptoms more than once or twice per week, asthma symptoms should not wake your child at night more than twice per month, and your child should be able to participate in all play, sports, and physical education activities.

Asthma medications come in a variety of forms, including the following:

• Metered-dose inhalers

• Dry powder inhalers

• Liquids that can be used in nebulizers

• Pills

Inhaled forms are preferred because they deliver the medication directly to the air passages with minimal side effects.

Medications Used to Treat Asthma

Asthma is different in every patient, and symptoms can change over time. Your health care provider will determine which asthma medication is best for your child based on the severity and frequency of symptoms and your child’s age. Children with asthma symptoms that occur only once in a while are given medications only for short periods. Children with asthma whose symptoms occur more often need to take controller medications every day.

Sometimes it is necessary to take several medications at the same time to control and prevent symptoms. Your health care provider may give your child several medications at first, to get the asthma symptoms under control, and then decrease the medications as needed. Your health care provider may also recommend a peak flow meter for your child to use at home to monitor lung function. This can help you make decisions about changing therapy or following the effects of changes made by your health care provider.

Asthma medications are divided into 2 groups: quick-relief medications and controller medications.

Quick-Relief Medications

Quick-relief medications are for short-term use to open up narrowed airways and help relieve the feeling of tightness in the chest, wheezing, and breathlessness. They can also be used to prevent exercise-induced asthma. These medications are taken only on an as-needed basis. The most common quick-relief medication is albuterol.

Controller Medications

Controller medications are used on a daily basis to control asthma and reduce the number of days or nights that your child has symptoms. Controller medications are not used for relief of symptoms. Children with symptoms more than twice per week or who wake up more than twice per month should be on controller medications.


Controller medications include the following:

• Inhaled steroids

• Long-acting bronchodilators

• Combination products that contain inhaled steroids and long-acting bronchodilators

• Leukotriene receptor antagonists (only available in pill form)

• Inhaled nonsteroids (such as cromolyn or nedocromil)

• Methylxanthines (for example, theophylline)

Inhaled corticosteroids are the preferred controller medication for all ages. When used in the recommended doses, they are safe for most children. In your child’s particular case, however, your health care provider may recommend another type of controller medication.

Asthma Management Plan

It is usually helpful to have an asthma management plan written down so you can refer to it from time to time. Such a plan should contain information on daily medications your child takes as well as instructions on what to do for symptoms. A plan should also be provided to your child’s school.

Exercise-Induced Asthma

Exercise can often trigger symptoms in children with asthma. It can almost always be prevented with use of quick-relief medications taken 10 to 15 minutes before exercise. If it occurs frequently, however, it may mean your child’s asthma is not under control. Proper asthma control can make a great difference in the ability for a child to exercise normally. It is important for parents to speak to their child’s physical education teachers and coaches about their child’s asthma management.


Management Aids

Devices to Help Deliver Asthma Medications

Medications for asthma can be given to your child using a variety of devices including the following:

• Nebulizer—This is often used with younger children. This device uses an air compressor and cup to change liquid medication into a mist that can be inhaled through a mouthpiece or mask. Inhaled steroids and quick-relief medications can be given this way.

• Metered-dose inhaler (MDI)—This is the most commonly used device for asthma medications. However, your child will need to learn how to use it properly, which means pressing (or actuating) the device while taking a deep breath at the same time. The technique is reviewed on the following pages. Some MDIs are “breath actuated,” that is, they give out a puff of medication when you start to take a breath. These types of MDIs are much easier to use, but are only available for one type of quick-relief medication. Spacers can be used to help relieve some of the coordination problems in using MDIs and should always be used when using inhaled steroids.

• Dry powder inhaler (DPI)—This device is available for some medications. It is easier to use because you do not need to coordinate breathing with actuation. It also has less taste, and often has a built-in counter to help keep track of doses taken and doses left.

Some asthma medications only come in pill form. However, inhaling the medication using one of the devices listed above is usually better because the medication passes straight into the airways. As a result, side effects are reduced or avoided altogether. Because there are several different inhalers on the market, your health care provider will suggest the one that is best for your child. There are important differences in the way they are used and in the amounts of medications they deliver to the airways. Your child will be taught how to use the inhaler, but her technique should be checked regularly to make sure she is getting the right dose of medication.

Peak Flow Meter

To help control asthma, your child may need to use a peak flow meter. This is a handheld device that measures how fast a person can blow air out of the lungs. Asthma treatment plans using peak flow meters use 3 zones—green, yellow, and red, like traffic lights—to help you determine


if your child’s asthma is getting better or worse. Peak flow rates decrease (the numbers on the scale go down) when your child’s asthma is getting worse or is out of control. Peak flow rates increase (the numbers on the scale go up) when the asthma treatment is working and the airways are opening up.

When to Use the Peak Flow Meter (if your health care provider has recommended one)

Check your child’s asthma using the peak flow meter at the following times:

• Every morning, before he takes any medications.

• If your child’s symptoms worsen or if he has an asthma attack. Check the peak flow rate before and after using medications for the attack. This will help you to see if the medications are working.

• Other times during the day, if your health care provider suggests.

Keep in mind, there are differences in peak flow rate measurements at different times of the day. These differences are minimal when asthma is well controlled. Increasing differences may be an early sign of worsening asthma. Also, children of different sizes and ages have different peak flow rate measurements.

Keep a record of your child’s peak flow numbers each day. This will help you and your health care provider see how your child’s asthma is doing. Bring this record with you when you visit the paediatrician.


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