Clear the air

Asthma is on the rise. Find out what causes it and how you can deal with it 

Asthma is a complicated disease, which can cause great discomfort for both children and adults. Although there isn’t a cure for this condition just yet, asthmatics can certainly manage and control symptoms for an easier life.

According to the Ministry of Health Malaysia’s Annual Report (2012), occupational asthma is among the top three types of occupational lung diseases. Asthma was also among the top five new diagnoses among the elderly in health clinics.  Urban Health spoke to Dr. Kent Woo, Consultant Allergy and Immunology (Paediatric and Adult) and Consultant Physician (Internal Medicine) at Gleneagles, Kuala Lumpur to find out more about this condition.

A tight squeeze

According to Dr. Woo, asthma is caused by inflammation of the airways in the lungs, which causes the airways to be hyper-reactive and sensitive. Upon exposure to irritants such as smoke, cold air or allergens, the inflamed airways will squeeze shut (bronchoconstriction).

Bronchoconstriction is what causes the symptoms of asthma, such as wheezing and shortness of breath. “The key feature about asthma is that bronchoconstriction is not permanent. The use of medicines called bronchodilators can reverse this airflow obstruction,” explains Dr. Woo.

Childhood disease…or is it?

Dr. Woo adds, “Around 60 % of children who wheeze in the first three years of their life will have their symptoms resolved by the time they are six years old. This group of children is labelled ‘transient wheezers’ and we think it is because they have small airways. This will be resolved once their lungs mature with age.” These children also have no allergies.

Conversely, children who wheeze and have allergies tend to be persistent wheezers and are eventually diagnosed as an asthmatic according to Dr. Woo. He also states that with some patients, the asthma can go into remission during adolescence and it may or may not recur later in their life.

Strange connection

In very young children, asthma can be a challenge to diagnose. Dr. Woo explains that this is because to measuring a child’s lung function as well as his airway hyper responsiveness is no easy task as the instruments involved aren’t always suitable for children.

“An allergist can evaluate the risk of a child developing asthma by looking at the child’s family history of asthma, presence of atopic dermatitis and through skin testing for sensitisation to aeroallergens (airborne substance that triggers an allergic reaction), “ says Dr. Woo. “Once an allergic trigger is identified, environmental control to reduce the allergen, can help reduce symptoms.”

Asthma Predictive Index

Dr. Woo explains that wheezing accompanied by symptoms such as tightness in the chest and shortness of breath, can be a sign of asthma. “A chronic cough (one that lasts more than eight weeks) can also be an indicator. In children, it can present as coughing after activities such as running or as night time cough.”

A doctor will obtain a proper history of the patient followed by a physical exam to look for the symptoms of asthma. “Pulmonary function testing (complete evaluation of the respiratory system) is also important in the diagnosis and management of asthma as it reveals the degree of lung obstruction caused by airway inflammation,” emphasises Dr. Woo.

After these tests are performed and a patient is diagnosed with asthma, he’ll be classified as having either intermittent or persistent asthma. “Persistent asthma is further subdivided into mild, moderate and severe. This will act as a general guideline for medication use for asthma control.”

To predict the risk of a child developing asthma, doctors formulated the Asthma Predictive Index. Its indicators are:

Parental history of asthma

-A diagnosis of Atopic Dermatitis or eczema

-A physician diagnosis of allergic rhinitis in the patient

Wheezing despite not having respiratory infections (temperature changes and exercise)

High eosinophils (white blood cells along with mast cells that control mechanisms related to allergy and asthma) in the blood > 4%. This can be detected with a blood test.

 

Triggers and ways to help

Dr. Woo lists exercise, exposure to air-borne irritants, such as pollution and allergen exposure, as triggers in sensitised individuals. In some patients with aspirin sensitivity and nasal polyps, the ingestion of nonsteroidal anti-inflammatory agents can cause an asthma attack. “For many asthmatics, viral respiratory tract infections can increase airway inflammation and trigger an attack, which is why asthmatic patients are recommended to undergo yearly influenza virus vaccination,” says Dr. Woo.

For wheezing, the use of a bronchodilator via puff inhalers should relieve symptoms. If the wheezing does not subside within an hour or if repeated doses of three times or more within a day are necessary, the person should see a doctor immediately or find closest urgent care centre such as the accident and emergency department at your local hospital.

Airway inflammation

The two important components of asthma are airway inflammation, which causes bronchoconstriction. “Many patients are focused on the bronchoconstriction component, as this is what causes the shortness of breath and wheezing. The use of bronchodilators, such as albuterol or salbutamol can quickly relieve their symptoms,” shares Dr. Woo. The airway inflammation component is the silent but most important part of the disease. “Taken as directed, inhaled corticosteroids are safe, well-tolerated and one of the most effective medications to treat airway inflammation. Inhaled steroids are not dangerous or addictive, and are different from the anabolic steroids that are abused for body-building.”

A common fear is that inhaled corticosteroids may reduce the rate of growth in children. “However studies have shown that children with uncontrolled asthma have poorer growth compared to children with controlled asthma on inhaled steroids. Proper use of asthma medications can reduce airway inflammation and lead to less medication use overall.”

Find, remove and follow up

Dr. Woo says asthmatics or the carers of asthmatics should take measures to identify and then avoid triggers. This may range from pet dander to dust mites and if found to be the trigger, weekly allergen control (washing bed sheets and vacuuming) is highly recommended.

“Asthmatics should also visit their doctor regularly so that their lung function can be measured to see if their airway inflammation is under control,” advises Dr. Woo. “Medication should be used as prescribed and patients shouldn’t stop taking their medication prematurely without supervision.”

Never fear, allergists are here!

Asthma can limit a person’s level of activity because it causes shortness of breath and wheezing. This is especially true for uncontrolled asthmatics who may shy away from physical activities because of the symptoms. With proper medication and good asthma symptom control, patients can lead a normal life.

It is best to speak to an allergy and immunology specialist to help identify the allergic triggers for their asthma. “We are trained in allergen specific immunotherapy for the treatment for allergies and asthma. Allergen immunotherapy has been shown to prevent development of asthma and can reduce symptoms and medication use in asthmatics,” assures Dr. Woo.

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