Asthma is divided into two distinct types: extrinsic and intrinsic.
Extrinsic asthma occurs when an asthmatic person is exposed to allergens, which trigger respiratory symptoms. This type of asthma is usually seasonal and worsens during the spring months. It is the most common type of asthma in children.
If the trigger for an asthma episode is not an allergen, it is considered intrinsic asthma.
The triggers for intrinsic asthma include:
- Respiratory infections
- Exposure to cold air
- Intense physical activity
- Smoke or smoking
Intrinsic asthma usually appears in the early years of adulthood.
Asthma can be the result of genetics, allergies, or the living environment of a person. Despite its long history, the exact cause(s) that lead to the development of asthma has not been found.
However, research has identified several things that can increase the risk of developing asthma during a person’s lifetime (Asthma Canada, 2022). These factors include:
- If one or both parents have asthma, then any children will be about 3 times as likely to develop asthma
- Males (AMAB–assigned males at birth) are more likely to have childhood asthma
- Females (AFAB- assigned female at birth) are more likely to have asthma during adulthood, which has been linked to differences in hormones after puberty (Chiarella et al., 2021)
- Asthma is more common in people whose allergic reactions impact primarily their eyes and nose
- If a parent has allergies, their children are more likely to develop asthma
- Chronic exposure to lung irritants (smoke, pesticides, chemicals, pollution, etc.)
- Repeated childhood respiratory infections
- Work-related exposure to respiratory irritants
- Exposure to mold or mildew
- Poor air quality
Some common triggers for asthma include:
- Dog, cat, and other pet dander
- Strong smells
- Cold air
- High humidity environment
- Exercise that leads to a heightened breathing rate
- Respiratory illnesses, bacterial or viral
What are the symptoms of asthma?
- Shortness of breath
- Chest tightness or congestion
- Whistling sound while breathing out
- Blue lips or nails
- Trouble sleeping or excessive fatigue with no clear cause
- Excessive sweating overnight
PLEASE CALL 911 IF YOU ARE A FAMILY MEMBER HAVE THE FOLLOWING SYMPTOMS:
- Blue lips or nails
- Constant coughing with no relief after taking medication or drinking water
- Strong wheezing or whistling breath
- Trouble speaking due to a lack of breath
- An asthmatic person leaning forward with hands or elbows on their knees/hips to breathe with any of the above symptoms
Asthma has two distinct phases, which can lead to a visit to the emergency room if not monitored. The acute phase is the one most commonly seen, where asthma is triggered and the asthmatic quickly experiences symptoms, commonly starting with shortness of breath and coughing.
The late phase is the inflammatory phase, where the body reacts to the acute phase by causing inflammation in the airways, effectively reducing the space available for air to pass into and out of the lungs.
As this late phase can occur hours after the acute phase, it is important to monitor your or your family member's symptoms even after the acute phase has passed.
This is especially important when children are involved, as they may be tired after an acute asthma attack and fall asleep. Chronically untreated asthma can be fatal due to repeated inflammation of the airways, which can result in collapsed airways.
The Copenhagen Prospective Studies on Asthma in Childhood (COPSAC) used 25 years of research and patient information to establish ways to detect children at risk of developing asthma in infancy (2023).
These methods include testing for specific bacteria in an infant’s airway, for gut health, and verifying an infant’s lung capacity.
If you suspect you or a family member has asthma, the first thing to do is schedule an appointment with a physician. At this appointment, the physician will ask for the following information:
- Symptoms experienced
- How often do they occur
- Any triggers noticed
- If someone else in your family has/had asthma
They will listen to the lungs and may ask you or your family member to use a spirometer. A spirometer is a tool that measures how much air a person can quickly blow out.
This test may be done a second time after the doctor has given you or your family member a bronchodilator, the most common asthma treatment, and the results are then compared. If the spirometry results improve significantly (>12% in children, >20% in adults), then this is considered an asthma-positive test (Yang et al., 2021).
If the doctor wants to perform further testing, then they will provide a referral to a pulmonary clinic for a pulmonary function test (PFT). During this test, a methacholine challenge test may be requested.
Methacholine is a substance that provokes the constriction of airways. In such cases, the PFT will be performed three times: to establish a baseline, to verify if the methacholine provoked a change, and if needed, after being given a bronchodilator to verify that their results are back to normal.
If the methacholine reduces the baseline by at least 20% and 200 mL, or if taking the medication increases the results by 20%, then the test is considered positive.
Other tests that could be requested by a doctor are:
- Nasal or airway swab to check for a high white blood cell count
- Allergy test
- Exercise PFT challenge (if the methacholine test is not recommended or unclear)
The treatment options for asthma are based on the length and severity of the episodes, along with how well-managed the asthma is. The first line of treatment for asthma is using a short-acting bronchodilator, an inhaled medication that quickly opens up the airways for about 4 hours.
It is considered a “rescue medication” as it takes effect quickly, within 15-20 minutes (Asthma Canada, 2022b). If asthma continues to happen frequently despite the use of a short-acting bronchodilator, then a long-acting bronchodilator or a corticosteroid may be added to the treatment.
The long-acting bronchodilator starts working after the acute phase ends and helps limit or prevent the late asthma phase. Inhaled corticosteroids target the inflammation that occurs during the late phase and can be used to reduce it if used daily.
The doses of the bronchodilators and corticosteroids may need to be readjusted over time to ensure the best possible treatment. It is possible that your doctor may
recommend adding a combination inhaler — a mixture of the long-acting bronchodilator and the corticosteroid — instead of using two different inhalers.
Should the use of the above two steps not be enough to control asthma, then the doctor will refer you or your family member to a pulmonary specialist. They may add a fourth type of medication, called an anticholinergic, to help control asthma until the appointment with the specialist.
Asthma Canada has created an informational pamphlet on the different kinds of medication and how to best use them. Always follow the directives of your doctor when taking inhalers.
The Wilderman Medical Clinic includes an allergy testing clinic, where the staff will be able to test for any allergies you or your family member may have and provide advice on reducing allergen exposure in order to reduce the possible triggers for allergy-related (or extrinsic) asthma attacks.
Asthma Canada. (2022a, April 19). Understanding Asthma – Asthma Canada. https://asthma.ca/get help/understanding-asthma/
Asthma Canada. (2022b). BreatheEasy Medication Pamphlet. In Asthma Canada. https://asthma.ca/wp content/uploads/2020/06/BreatheEasy_Medications-Final-2022-EN.pdf
Bisgaard, H., Chawes, B. L., Stokholm, J., Mikkelsen, M., Schoos, A. M., & Bønnelykke, K. (2023). 25 Years of translational research in the Copenhagen Prospective Studies on Asthma in Childhood (COPSAC). The Journal of Allergy and Clinical Immunology, 151(3), 619–633. https://doi.org/10.1016/j.jaci.2022.11.022
Chiarella SE, Cardet JC, Prakash YS. Sex, Cells, and Asthma. Mayo Clin Proc. 2021 Jul;96(7):1955- 1969. doi: 10.1016/j.mayocp.2020.12.007. PMID: 34218868; PMCID: PMC8262071.
Yang, C. L., Hicks, E., Mitchell, P., Reisman, J., Podgers, D., Hayward, K. M., Waite, M., & Ramsey, C. D. (2021). Canadian Thoracic Society 2021 Guideline update: Diagnosis and management of asthma in preschoolers, children and adults. Canadian Journal of Respiratory, Critical Care, and Sleep Medicine,
5(6), 348–361. https://doi.org/10.1080/24745332.2021.1945887