Asthma is a chronic disease that results from a constricted airway. The airway consists of two bronchial tubes that branch into several tertiary bronchi. The bronchial tubes allow air to pass in and out of the lungs, but when they are persistently inflamed, the airway tightens. Most often, this leads to symptoms such as shortness of breath, chest tightness, coughing, and wheezing.
Asthma symptoms can be worsened by pre-existing allergies to allergens such as pollen, mold, and dust. This is known as allergic asthma.
Many children develop asthma before 5 years of age. However, 20% of children are able to outgrow their asthma by age 19.
Asthma that presents predominantly as a dry cough and without symptoms of wheezing, shortness of breath, or chest tightness is called cough-variant or cough-dominant asthma. Generally, cough-variant asthma does not resolve with over-the-counter cough medicines. Instead, asthma specific medications such as bronchodilators and low dose inhaled corticosteroids must be prescribed for treatment.
Quickly breathing in dry air during high intensity physical activity can dehydrate the bronchial tubes, causing the airway to narrow. This is known as exercise-induced asthma, or exercise-induced bronchoconstriction. Many people, including professional athletes, suffer from exercise-induced asthma.
Exposure to irritants like dust, chemicals, gases, and other harmful substances at work may lead to occupational asthma. Some workers are at a higher risk of developing occupational asthma, including farmers, laboratory personnel, and those who handle plastics, metal, and wood.
Symptoms of asthma include wheezing, shortness of breath, chronic dry cough, chest tightness or pain, and increased mucus in the lungs. Many of these symptoms can worsen at night and can cause difficulty sleeping. Asthma symptoms can present and worsen during physical activity, with stress, with exposure to allergens, and with other illnesses such as a cold. Pollution, smoke, cold air, and weather changes may trigger a flare-up in asthma symptoms, causing an asthma attack.
Pediatric Asthma Symptoms
Coughing and wheezing are the two most common asthma symptoms in children. Wheezing is a high-pitched, musical sound produced by air forced through narrow airways. Wheezing is considered the most distinctive indicator of asthma in childhood, but in some pediatric patients, a chronic dry cough may be the only symptom. Most children with asthma develop symptoms before age 5. These symptoms include: Coughing – at night, seasonally, with exercise, and when exposed to allergens; a dry cough that lasts more than three weeks raises suspicion for asthma Wheezing – a whistling sound when your child exhales Fatigue – from poor sleep as a result of coughing and difficulty breathing at night. Rapid breathing or shortness of breath Chest tightness or pressure Poor school attendance or performance Decreased participation in sports and other physical activities
Spirometry Breathing Tests
A spirometer is a small instrument that can be used to measure how much and how well you can breathe air in and out. You will be asked to breathe in as much air as possible and then exhale as hard and as fast as possible. Spirometry helps to assess asthma severity and also reveals how well treatments are working when a before and after test is done. For infants and children below five years, spirometry often cannot be performed, so a trial of medications may help to confirm an asthma diagnosis.
Additional allergy testing may help identify specific triggers that worsen asthma symptoms. Your doctor may suggest a blood test or skin test.
Asthma Management & Treatment
Asthma cannot be cured, but it can be well managed with therapies that control symptoms. Chronic asthma management is intended to: 1) decrease the intensity and frequency of asthma symptoms, 2) minimize the adverse side effects of current therapies, and 3) prevent hospitalizations for severe asthma flare-ups that can result in reduced lung growth or loss of lung function over time.
Because the types and doses of asthma medicines will vary depending on asthma severity, patient age, and drug side effects, medication compliance is important. Identifying and avoiding triggers of asthma symptoms is also critical. Your asthma management plan may change over time, so monitor your symptoms and notify your doctor of any changes.
Controller medications are those that are taken long term to prevent asthma symptoms and attacks. Examples of controller medications include inhaled and oral corticosteroids, long-acting beta agonists (LABAs), combination inhalers containing both a corticosteroid and a LABA, as well as leukotriene modifiers and anticholinergics.
Rescue medications provide rapid relief and are short-acting. They are used to quickly relax and open the airways during an asthma attack. Examples of rescue medicines include short-acting inhaled beta2-agonists such as pirbuterol, albuterol, and levalbuterol as well as oral and IV corticosteroids. Rescue medications stop asthma symptoms, but they do not control the airway inflammation that leads to these symptoms. Asthma that requires the use of quick-relief medicine more than two times per week is not well controlled.
Immunotherapy: Biologic Injections & Allergy Shots
FDA approved biologic drugs such as reslizumab, omalizumab, mepolizumab, dupilumab, and benralizumab can be injected under the skin or by IV to control and prevent severe asthma symptoms. Your allergist will run blood tests to determine the most effective biologic injection for you.
Patients with allergy-induced asthma may benefit from allergy shots (immunotherapy) and/or other allergy medications. Allergy shots work by injecting small quantities of the allergen so that your body eventually develops a tolerance and desensitization to the allergen.
Preventing Asthma Exacerbation: Vaccinations
Viral respiratory infections can create complications for individuals with asthma, triggering up to 50% of asthma exacerbations in both school-aged children and adults. Respiratory viruses such as influenza promote inflammation in the airway, which can lead to wheezing. Asthma patients should have all of their vaccinations up to date to reduce their risk of developing complications from respiratory infections.
 Sujani Kakumanu, MD. Role of viruses in wheezing and asthma: An overview. UpToDate. Accessed February 2020.
 Julie M Marchant, MBBS, FRACP, PhDAnne B Chang, MBBS, FRACP, PhD, FAPSR, FAHMS. Causes of chronic cough in children. UpToDate. Accessed February 2020.
 Christopher H Fanta, MD. An overview of asthma management. UpToDate. Accessed February 2020.
 Augusto A Litonjua, MDScott T Weiss, MD, MS Natural History of Asthma. UpToDate. Accessed February 2020.