Bronchial asthma (BA) is a chronic inflammatory disease of the airways characterized by bronchial hyperreactivity and a variable degree of airway obstruction. It is a condition in which your airways narrow and swell and may produce extra mucus. This can make breathing difficult and trigger coughing, a whistling sound (wheezing) when you breathe out and shortness of breath. (https://www.mayoclinic.org/diseases-conditions/asthma/symptoms-causes/syc-20369653)
Asthma affects more than 25 million people in the U.S. currently. This total includes more than 5 million children. Asthma can be life-threatening if you don’t get treatment. (https://my.clevelandclinic.org/health/diseases/6424-asthma)
What are the causes of BA?
Many factors have been linked to an increased risk of developing asthma, although it is often difficult to find a single, direct cause.
Asthma is more likely if other family members also have asthma – particularly a close relative, such as a parent or sibling.
Urbanization is associated with increased asthma prevalence, probably due to multiple lifestyle factors.
Events in early life affect the developing lungs and can increase the risk of asthma. These include low birth weight, prematurity, exposure to tobacco smoke and other sources of air pollution, as well as viral respiratory infections.
Exposure to a range of environmental allergens and irritants are also thought to increase the risk of asthma, including indoor and outdoor air pollution, house dust mites, moulds, and occupational exposure to chemicals, fumes or dust.
Asthma is more likely in people who have other allergic conditions, such as eczema and rhinitis (hay fever).
What is an asthma attack?
When you breathe normally, muscles around your airways are relaxed, letting air move easily and quietly. During an asthma attack, three things can happen:
Bronchospasm: The muscles around the airways constrict (tighten). When they tighten, it makes your airways narrow. Air cannot flow freely through constricted airways causing a “wheezing” sound while breathing.
Inflammation: The lining of your airways becomes swollen. Swollen airways don’t let as much air in or out of your lungs.
Asthma is broken down into types based on the cause and the severity of symptoms. Healthcare providers identify asthma as:
Intermittent: This type of asthma comes and goes so you can feel normal in between asthma flares.
Persistent: Persistent asthma means you have symptoms much of the time. Symptoms can be mild, moderate or severe. Healthcare providers base asthma severity on how often you have symptoms. They also consider how well you can do things during an attack.
Exercise-induced Asthma: This type is triggered by exercise and is also called exercise-induced bronchospasm.
Occupational Asthma: This type of asthma happens primarily to people who work around irritating substances.
Asthma-COPD overlap syndrome (ACOS): This type happens when you have both asthma and chronic obstructive pulmonary disease (COPD). Both diseases make it difficult to breathe.
Asthma symptoms vary from person to person. For example, you may have symptoms all the time or mostly during physical activity.
Most people with asthma have attacks separated by symptom-free periods. Some people have long-term shortness of breath with episodes of increased shortness of breath. Wheezing or a cough may be the main symptom.
Asthma attacks can last for minutes to days. An asthma attack may start suddenly or develop slowly over several hours or days. It may become dangerous if airflow is severely blocked.
Symptoms of asthma include:
Pulling in of the skin between the ribs when breathing (intercostal retractions)
Shortness of breath that gets worse with exercise or activity
Whistling sound or wheezing as you breathe
Pain or tightness in the chest
Difficulty sleeping
Abnormal breathing pattern (breathing out takes more than twice as long as breathing in)
Cough with or without sputum (phlegm) production
Emergency symptoms that need prompt medical help include:
Bluish colour to the lips and face (cyanosis)
Decreased level of alertness, such as severe drowsiness or confusion, during an asthma attack
The health care provider will use a stethoscope to listen to your lungs. Wheezing or other asthma-related sounds may be heard. The provider will take your medical history and ask about your symptoms. Tests that may be ordered include:
Allergy testing -- skin test or a blood test to see if a person with asthma is allergic to certain substances like pets, dust, mold or pollen.
Arterial blood gas -- often done in people who are having a severe asthma attack.
Chest x-ray or CT scan of the chest -- to check other conditions.
Lung function tests, including peak flow measurements or spirometry.
Provocative testing for exercise and cold-induced asthma measures airway obstruction before and after you perform vigorous physical activity or take several breaths of cold air.
The definitive endpoint of asthma management is the achievement of the best possible quality of life. Non-pharmacologic treatment include:
Removal of allergens (especially pets with feathers or fur).
Structured patient education: improved self-management leading to better symptomatic control, reduction of the number of asthma attacks and emergency situations, improved quality of life, and improvement in various other parameters of disease course including days taken off from school or work and days spent in hospital.
Physical training (reduction of asthma symptoms, improved exercise tolerance, improved quality of life, reduced morbidity).
Respiratory therapy and physiotherapy (e.g., breathing techniques, pursed-lip breathing).
Smoking cessation (with medical and non-medical aids, if necessary).
Pharmacologic treatment include preventive, long-term control medications reduce the swelling (inflammation) in your airways that leads to symptoms. Quick-relief inhalers (bronchodilators) quickly open swollen airways that are limiting breathing. In some cases, allergy medications are necessary.
Long-term asthma control medication are generally taken daily, and are the cornerstone of asthma treatment. These medications keep asthma under control on a day-to-day basis and make it less likely to have an asthma attack. Types of long-term control medications include:
Leukotiene modifiers such as montelukast (Singulair), zafirlukast (Accolate) and zileuton (Zyflo) — help relieve asthma symptoms.
Combination inhalers such as such as fluticasone-salmeterol (Advair HFA, Airduo Digihaler, others), budesonide-formoterol (Symbicort), formoterol-mometasone (Dulera) and fluticasone furoate-vilanterol (Breo Ellipta) — contain a long-acting beta agonist along with a corticosteroid.
Theophylline (Theo-24, Elixophyllin, Theochron) is a daily pill that helps keep the airways open by relaxing the muscles around the airways. It's not used as often as other asthma medications and requires regular blood tests.
Quick-relief (rescue) medication are used as needed for rapid, short-term symptom relief during an asthma attack. They may also be used before exercise if your doctor recommends it. Types of quick-relief medications include:
Short-acting beta agonist: These inhaled, quick-relief bronchodilators act within minutes to rapidly ease symptoms during an asthma attack. They include albuterol (ProAir HFA, Ventolin HFA, others) and levalbuterol (Xopenex, Xopenex HFA). Short-acting beta agonists can be taken using a portable, hand-held inhaler or a nebulizer, a machine that converts asthma medications to a fine mist. They're inhaled through a face mask or mouthpiece.
Anti-cholinergic agents: Like other bronchodilators, ipratropium (Atrovent HFA) and tiotropium (Spiriva, Spiriva Respimat) act quickly to immediately relax your airways, making it easier to breathe. They're mostly used for emphysema and chronic bronchitis, but can be used to treat asthma.
Oral and intravenous corticosteroids include prednisone (Prednisone Intensol, Rayos) and methylprednisolone (Medrol, Depo-Medrol, Solu-Medrol) — relieve airway inflammation caused by severe asthma. They can cause serious side effects when used long term, so these drugs are used only on a short-term basis to treat severe asthma symptoms. (https://www.mayoclinic.org/diseases-conditions/asthma/diagnosis-treatment/drc-20369660)
