Asthma is a disease characterized by a more or less important inflammation of the respiratory tracts, in the bronchi and small bronchi, the bronchioles. It results in difficulty breathing, shortness of breath, wheezing, or a feeling of tightness in the chest.
Asthma is a chronic disease most often manifested by attacks interspersed with periods when breathing is normal. In some people, however, asthma causes permanent difficulty in breathing, interfering with daily activities.
Asthma is often linked to an abnormal reaction of the airways to various stimuli (allergens in the air, smoke, etc.).
The asthma attack
An asthma attack is the sudden worsening of symptoms. In many people asthma manifests itself with occasional attacks, breathing is normal apart from the attacks.
An asthma attack often begins with a dry cough, followed by difficulty in breathing, which causes clearly audible wheezing. It is usually accompanied by the expectoration of mucus (coughing and spitting up).
During an attack, the opening of the bronchi is reduced due to a strong inflammatory reaction and contraction of the muscles in the wall of the bronchi.
Attacks can be relieved effectively with medication. However, they are potentially dangerous, especially in frail people (the elderly, suffering from a respiratory infection, etc.).
Prevalence of asthma
Since the 1960s, asthma has been steadily increasing in industrialized countries. It is estimated that in the United States, more than 25 million people have asthma. Women seem to be slightly more affected than men (9.4% against 6.7%).
Two periods in life seem to be more conducive to the onset of asthma: childhood and early 40s.
One in 8 children who have it (between 8% and 12% of children 11 and under) have asthma symptoms. It is a child’s first chronic illness. Fortunately, about half of these children will become completely asymptomatic during their teenage years.
Causes of asthma
The causes of asthma are not well known, although it is known that there are both genetic and environmental risk factors.
Inflammation of the airways results in the production of thick mucus inside the bronchi, which hinders the flow of air. At the same time, the muscles around the bronchi contract, causing the bronchi to “close” (bronchospasm). This is what causes breathing difficulties.
Asthma is associated with respiratory allergies in about 80% of cases, but it is not always allergic in origin. In people with asthma, there is excessive sensitivity of the bronchi (hyperreactivity) to one or more substances.
The following factors can help trigger an asthma attack or make your breathing more difficult, but they are not the cause of asthma.
- Airborne allergens (dust, pollen, animal hair, mites).
- Air pollutants (irritants in the workplace, smoke from wood fires, exhaust gases, air pollution, etc.).
- Tobacco smoke.
- Foods (food allergies) or food additives, such as sulphites.
- Certain medications (aspirin and other nonsteroidal anti-inflammatory drugs, beta-blockers).
- Respiratory tract infections (colds, bronchitis, sinusitis, etc.), because they cause local inflammation.
- Exercise, especially if done outdoors in the winter, in cold, dry weather.
- Strong emotions (laughter, crying, anger, excitement), especially in children.
In some people, asthma attacks are rare and do not have a serious impact on daily life. However, asthma can become more severe when the attacks are frequent and the symptoms are severe. In some cases, breathing difficulties and shortness of breath persist even between attacks.
Here are some signs of severe or poorly controlled asthma:
- symptoms during the night;
- limitation of activities during the day;
- the need to use inhalers several times a day or during the night;
- attacks that require hospitalization.
Poorly controlled asthma can cause permanent symptoms. Exceptionally, it can be complicated with respiratory distress and endanger the lives of people who suffer from it. Each day, around 10 adults die from an asthma attack in the United States. Most of these deaths could be avoided by good management of the disease.
Thus, the vast majority of people with asthma can live quite normally, provided they take their treatment properly. In addition, it is rare that seizures occur suddenly without warning signs. Learning to recognize these signs allows you to act in time to reduce the severity of seizures.
Symptoms of asthma
Symptoms can be intermittent or persistent. They can appear after exercise or in the presence of another trigger, and they are usually most noticeable at night and in the early morning.
- Difficulty breathing or shortness of breath (dyspnea)
- A feeling of tightness, chest tightness
- A dry cough
Note: For some people, asthma only results in a persistent cough that often appears at bedtime or after exercise.
In an asthma attack, the symptoms of shortness of breath, cough, and sputum worsen. If, in addition, the following symptoms are present, it is imperative to call for help or go to the emergency room, in order to control the crisis as quickly as possible:
- An increased heart rate;
- Difficulty speaking or coughing;
- Great anxiety, confusion and restlessness (especially in children);
- A bluish coloration of the fingers or lips;
- Disturbances of consciousness (drowsiness);
People at risk for asthma
- People with a genetic predisposition to allergies or having parents or siblings with asthma.
- People with low birth weight.
- Obese people.
- People with gastroesophageal reflux disease. Although reflux is not a cause of asthma, it is considered to be a worsening factor or even a trigger for asthma symptoms.
The increase in the number of asthmatics in recent decades may be attributable to the following external factors:
- People who are frequently exposed in their work environment to chemicals, for example paint, hair styling products, metals, plastics, etc.
- Pollution. More and more people live in the heart of urban areas, where air pollution is high.
- Exposure to tobacco smoke. Maternal smoking during pregnancy also increases the risk of asthma in children.
- Active and passive smoking irritates the airways and makes asthma worse.
Prevention of asthma
Treatments aim to make asthma symptoms go away, but in some people, asthma remains a chronic disease with periods of improvement and worsening. Sometimes asthma goes away after adolescence, especially if it was treated properly in childhood and there is no allergic ground.
For the moment, the only recognized basic preventive measure is to avoid active and passive smoking. Tobacco smoke irritates the respiratory tract, which creates a breeding ground for respiratory disease. Currently, there is no known measure to prevent asthma; there is no medical consensus in this regard.
Eating enough fiber in fruits and vegetables may help prevent asthma. The development of asthma would depend on the amount of fruits and vegetables consumed. Intestinal bacteria ferment dietary fiber in the digestive tract from fruits and vegetables. This helps transport fatty acids into the blood that influence the immune response of the lungs. This is shown in mice, which have the same functions on this type of reaction as humans.
Breastfeeding a child also provides some protection against asthma. It seems to be linked to allergenic products which, consumed by the mother during breastfeeding, pass into the milk, subsequently leading to tolerance to these allergenic substances.
Various avenues of prevention have been explored with regard to asthma caused by allergies.
Early detection measures
Asthma can be detected early in its onset with spirometry tests. These are measurements of the capacity of the lungs (for example, the volumes and rates of air flowing through the lungs on inspiration and expiration), taken using a spirometer. For the patient, it suffices to blow into a small electronic device with a mouthpiece. Spirometry has been used for several years in the diagnosis of asthma and chronic obstructive pulmonary disease (COPD). This examination is carried out on prescription from the attending physician, at a pulmonologist, or at a hospital.
Measures to reduce the intensity and frequency of seizures
General measures to prevent asthma
When asthma is strongly linked to allergies, desensitization treatment can help prevent asthma attacks. To do this, allergy tests must be undertaken to find out the substance that triggers the symptoms.
With your doctor, discover the factors that provoke the attacks and avoid them as much as possible: allergies, activities, behaviors, etc. Watch for warning signs of worsening asthma, so you can act quickly as your doctor advises. These signs can vary from person to person:
- Dry cough or wheezing;
- Shortness of breath;
- Oppression in the chest;
- Symptoms occurring at night;
- More frequent use of the crisis medication (spray);
- If you are using a flow meter, the 30% drop in peak flow is a warning sign of an exacerbation.
It is important for a person with asthma to always carry their medication with them so that they can relieve symptoms from the onset of the attack and prevent it from getting worse. Also at school, children with asthma should have their inhalers handy. If your child has asthma, it is good to tell the teachers to improve the child’s care in the event of a crisis.
More taking the following steps will greatly reduce the risk of having asthma attacks:
- Control mold, animals, pollens and other respiratory irritants, especially if asthma is allergic.
- Mold is found in damp and overly insulated rooms; to combat it, make sure that the rooms are well ventilated;
- In case of an allergy to animals, consider removing the animals from the house;
- Avoid exposure to pollen by keeping your house windows closed. Make sure that the filters of indoor ventilation devices are clean to properly recycle the indoor air;
- Avoid exposure to respiratory irritants.
- Control mites (dust mites). The mites feed mainly on fragments of dead skin and thrive in hot and humid environments. In case of allergy:
- Use an anti-parasite cover for the mattress and pillows;
- Wash the bedding with 60% water at least once or twice a month;
- Monitor the humidity level. Keep humidity levels low in the house and in the bedroom by ventilating daily if possible. Likewise, ventilate your bathroom and kitchen properly, as these are particularly humid rooms.
- Control dust. Controlling dust in the bedroom is a fundamental strategic element.
- Keep the closet clean.
- Avoid drapes and horizontal blinds that collect dust.
- Avoid carpets, otherwise vacuum them frequently and steam wash them regularly.
- Avoid woolen blankets and down comforters.
- Wash soft toys and dolls regularly.
- Avoid exposure to tobacco smoke. It is recommended to avoid smoky places, and not to smoke in houses or cars. Parents of children with asthma or people with asthma should do everything they can to stop smoking because smoke is an irritant that makes asthma considerably worse.
- Avoid going out in the event of pollution peaks. Asthmatics should limit outings and especially physical effort in the event of a pollution peak.
- Be vigilant about medications. Certain drugs such as acetylsalicylic acid (Aspirin®) or certain antihypertensive drugs such as beta blockers can cause attacks in some asthmatics. We must therefore be vigilant. When you want to take medicines (even those that seem “harmless” for colds or flu), you should consult a doctor or pharmacist.
- Exercise. People with well-controlled asthma shouldn’t stop doing physical activities — on the contrary! Regular exercise in the open air and breathing exercises is recommended. Regular training improves lung capacity and dilation of the bronchi, and gradually lowers the threshold for onset of exercise-related asthma. In addition, physical activity helps, at all ages, improve the quality of life and reduce stress. It should be noted, however, that individual and endurance sports cause more asthma than team sports. Asthma can be prevented in part by warming up before strenuous exercise and gradually decreasing the effort at the end of the exercise period. People who react to cold, dry air can cover their mouth and nose with a scarf, which will warm and humidify the inspired air. If these preventative measures are not sufficient, the use of an inhaled bronchodilator 10 to 15 minutes before exercise is indicated. If exercise-related asthma is too severe, it may mean that the overall treatment is inadequate. It is then necessary to speak about it with his doctor.
- Take time to relax. Sometimes stress or anxiety causes asthma attacks. In this sense, anything that helps reduce stress and anxiety, such as deep breathing, massage, autogenic training, etc., helps to better control the disease. See also our cards in the Therapies section.
Treatment of asthma
Asthma is often a chronic disease that requires regular treatment, even between attacks. Medicines to control asthma do not provide a cure. They make breathing easier by increasing the opening of the bronchi (bronchodilation) and reducing inflammation. Most of them are taken by inhalation, which allows them to work quickly with as few side effects as possible. The doctor also tries to give the smallest dose of medication for symptom control with the best tolerability of the treatment.
Yet, despite effective treatment, 6 in 10 people with asthma fail to control their symptoms. The main causes are poor understanding of the disease, fear of side effects, and forgetting to take medication. However, the side effects of treatments taken by inhalation are minimal compared to the risks associated with severe and frequent asthma attacks
Inhalation technique. Using inhalers sounds simple, but it takes some techniques to be effective. However, less than half of asthmatics use their inhaler correctly. The different inhalers (metered-dose inhalers, dry powder inhalers, and nebulizers) each have a specific mode of use. The doctor and pharmacist can explain the right actions to you.
- Metered aerosols. You must shake the aerosol well and hold it vertically. After slowly emptying the lungs, breathe in slowly and very deeply through your mouth, triggering the aerosol during the first second of inspiration. You should then hold your breath for 5 to 10 seconds, then breathe out slowly.
- Dry powder inhalers (eg: Turbuhaler®). These systems are easier to use because they do not require coordination of inspiration and trigger. Breathe in as hard and as fast as you can, hold your breath for 10 seconds, and breathe out outside the inhaler.
- Inhalation chambers. They are used with a metered dose inhaler in children under 8 years old and the elderly. In young children, inhalation is done with a face mask, which should be kept on the face for at least 6 calm breaths.
People with asthma are increasingly called upon to monitor their respiratory condition. For example, people with severe asthma can measure their peak expiratory flow at home in order to adjust their treatment themselves according to the results. Training must have been taken beforehand.
Medicines to treat asthma
There are 2 categories of medicines to control asthma symptoms. The first, called crisis or rescue medications, should be taken if you have symptoms. They have an immediate relief action but do not help calm the inflammation of the bronchi.
The other drugs are the control or background treatment. They should be taken every day, even if there is no respiratory discomfort as soon as the asthma is moderate and persistent. They help reduce inflammation of the bronchi and space out attacks. If not taken regularly, the frequency and severity of seizures increase, as does the need for rescue medication.
Many people with asthma do not fully understand the difference between crisis treatment and control treatment. Make sure you understand what each of your medicines is for and how often you should use them.
Crisis (or rescue) treatment
Crisis medications have different terms, including rapid-acting bronchodilators or short-acting beta-agonists. They are only used to relieve the symptoms of an attack (cough, chest tightness, wheezing, and shortness of breath) or before exercise for asthma on exertion. In mild, intermittent asthma, seizure therapy may be the only medicine needed.
These medications include salbutamol ((Ventoline®, Ventilastin®, Airomir®, Apo-Salvent®, Novo Salmol®) or terbutaline (Bricanyl®). They are taken by inhalation and widen the airways very quickly, 1 to 3 minutes. There are few side effects if used occasionally, but in high doses, they can cause tremors, nervousness, and increased heart rate. When you feel the need to take it often (usually more than 3 times a week ), this means that asthma is not adequately controlled, and DMARDs are needed to treat the inflammation.
For someone with asthma, it is important to always have their bronchodilator with you, as an asthma attack can happen anywhere. It should be taken at the first symptoms of an attack and wait at least 30 seconds between 2 inhalations.
Ipratropium bromide inhalation (rarely). It is an anticholinergic that blocks the action of a chemical that causes the muscle in the airways to contract. Less effective than inhaled beta2 agonists, it is sometimes used in cases of intolerance to them. It takes 1 to 2 hours for maximum effect.
Drugs as a basic (control) treatment
Unlike seizure medications or rescue medications, DMARDs (control) medications do not immediately relieve symptoms. They are slow-acting and are long-term effects in reducing inflammation and the frequency of seizures. This is why it is important to take them daily.
- Corticosteroids. Corticosteroids decrease inflammation in the airways and therefore the production of mucus. They are usually taken in small doses as an inhalation (spray), on a daily basis (for example, Alvesco® and Pulmicort®). The doctor prescribes the lowest effective dose possible. They can also be taken as tablets in severe asthma for a short period of a few days (example: prednisolone, methylpredinosolone). Whether taken by inhalation or in tablets, they work the same way, but inhaling allows for much lower doses, a much more localized action and therefore fewer side effects. This class of drugs is the most effective in controlling asthma. Their effect is felt after a few days of use. Taken by inhalation and in moderate doses, corticosteroids have few side effects, even if taken for a long time. Hoarseness and hoarseness or the appearance of thrush (or candidiasis, due to yeast forming white patches on the tongue) are the most common side effects. Therefore, rinse your mouth after inhaling each dose. Corticosteroid tablets have more serious long-term side effects (weakening of the bones, increased risk of cataracts, etc.). They are reserved for cases of severe asthma, associated with other treatments.
- Long-acting bronchodilators. These are prescribed in combination when inhaled corticosteroids alone are not sufficient to control asthma symptoms. Long-acting beta2 agonists cause bronchodilation for 12 hours. Their effectiveness can be rapid in 3 to 5 minutes like formoterol® (ex Foradil®, Asmelor®) or slower after 15 minutes like salmeterol (Serevent®). They are used in combination with a corticosteroid. There are inhalers that combine the two types of drugs such as Seretide® (fluticasome / salmeterol). Combinations with formoterol (Symbicort®, Innovair® and Flutiform®) can also be used as a rescue medication, although they also act on inflammation in the long term.
- The Antileukotrienes. Taken orally, they decrease inflammation caused by leukotrienes, substances contributing to the inflammatory response.In France, an antileukotrienes is available: montelukast (Singulair®). In Canada, there is also lezafirlukast (Accolate®). They can be used alone or in combination with inhaled corticosteroids. They are indicated to prevent asthma during exercise, in mild asthma, for people whose asthma is not controlled by corticosteroids alone inhaled, and for those who misuse their spray.
- Theophylline. It is the oldest of the bronchodilators (eg: Theostat®). It is rarely used today because an effective dosage without side effects is difficult to find. It can be prescribed as a tablet to take with the evening meal in people who have difficulty taking the sprays.
- Anti-immunoglobulin E. This class of drugs is used to treat severe allergic asthma in people whose asthma is difficult to control with other treatments. Omalizumab (Xolair®) is the only drug in this class available in 2015. It is given as injections under the skin once or twice a month.
It is really important to use a controller medicine as directed by your doctor, even if there are no symptoms. Without regular use, inflammation of the bronchi persists and asthma attacks may become more frequent.
Mandell is currently working towards a medical degree from the University of Central Florida. His main passions include kayaking, playing soccer and tasting good food. He covers mostly science, health and environmental stories for the Scientific Origin.