Asthma is a chronic respiratory condition characterized by inflammation and narrowing of the airways, leading to difficulty breathing, wheezing, chest tightness, and coughing.
It affects people of all ages, with varying degrees of severity, and can significantly impact daily life.
Despite extensive research and advancements in treatment, asthma remains a prevalent health concern globally, requiring ongoing management and awareness to mitigate its effects and improve the quality of life for those affected.
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What is Asthma?
Asthma is a chronic, obstructive respiratory condition that causes inflammation and narrowing of the airways in the lungs. This leads to recurring episodes of dyspnea and wheezing. The severity of asthma varies, and an episode can occur due to certain triggers and other causes.
Causes
The exact cause of asthma is not fully understood, but it is believed to result from a combination of genetic and environmental factors. These factors can lead to inflammation and narrowing of the airways, affecting breathing.
Key contributors to the development of asthma include:
- Genetic Susceptibility: A family history of asthma or allergic conditions can increase the risk of developing asthma.
- Environmental Allergens: Exposure to allergens such as pollen, dust mites, mold spores, pet dander, and cockroach waste can trigger asthma in genetically susceptible individuals.
- Respiratory Infections: Early childhood infections, particularly viral respiratory infections, can damage lung tissue and increase the risk of developing asthma.
- Air Pollution: Exposure to pollutants, such as ozone, nitrogen dioxide, and particulate matter, especially in early childhood, can contribute to developing asthma.
- Occupational Exposures: Inhaling chemical irritants, industrial dusts, gases, or fumes in the workplace can lead to occupational asthma.
- Tobacco Smoke: Both prenatal exposure to maternal smoking and postnatal exposure to secondhand smoke are risk factors for developing asthma in children.
- Dietary Factors: Some evidence suggests that obesity, as well as a lack of certain nutrients (such as vitamins D and E, omega-3 fatty acids), might play a role in asthma development.
- Hygiene Hypothesis: This theory suggests that reduced exposure to bacteria and other infections in early childhood could increase susceptibility to allergic diseases by suppressing the natural development of the immune system.
- Psychological Stress: High levels of stress and anxiety can weaken the immune system and increase the risk of asthma.
Note: Understanding these factors helps in identifying individuals at risk and potentially mitigating those risks through lifestyle changes and environmental management.
Signs and Symptoms
The signs and symptoms of asthma can vary from mild to severe and may include:
- Wheezing
- Dyspnea
- Shortness of breath
- Chest tightness
- Coughing
- Pursed-lip breathing
- Difficulty speaking
- Rapid breathing
- Increased A-P diameter of the chest
- Hyperresonant chest percussion note
- Diaphoresis
- Accessory muscle usage
- Diminished breath sounds (during a severe episode)
Note: Symptoms often vary over time and can flare up in response to certain triggers, such as allergens, cold air, physical activity, or stress.
Diagnosis
Diagnosing asthma involves a combination of medical history evaluation, physical examination, and specific tests to assess lung function and identify possible asthma triggers.
Here’s a typical diagnostic process:
- Medical History: The doctor will ask about symptoms, their frequency, and any family history of asthma or allergic conditions. Understanding when and how symptoms occur can help identify potential asthma triggers.
- Physical Examination: This may include listening to the patient’s lungs and checking for signs of allergic conditions, such as eczema or allergic rhinitis.
- Spirometry: A pulmonary function test (PFT) that measures how much air one can inhale and exhale and how quickly one can exhale, which helps detect the narrowing of the bronchial tubes.
- Peak Flow Meter: A simple device used to measure how hard one can exhale. Decreased peak flow readings can indicate that asthma is worsening or not well-controlled.
- Methacholine Challenge Test: Used if initial tests are inconclusive. Methacholine, when inhaled, will cause mild narrowing of the airways in people with asthma, indicating the presence of reactive airways.
- Allergy Testing: Skin tests or blood tests can be performed to identify specific allergic triggers, which is helpful for managing allergic asthma.
- Exhaled Nitric Oxide Test: Measures the amount of nitric oxide in the breath, which can indicate inflammation in the lungs.
- Imaging Tests: Chest x-rays or CT scans can rule out other conditions that might be causing symptoms, such as a foreign body or a structural abnormality.
- Fractional Exhaled Nitric Oxide Test: Assesses airway inflammation, a sign of asthma, by measuring the levels of nitric oxide in the exhaled breath.
Note: The results from these tests help healthcare providers confirm an asthma diagnosis, assess its severity, and tailor a management plan for the patient.
Treatment
Asthma treatment focuses on controlling symptoms and preventing asthma attacks. It typically involves a combination of medication and lifestyle adjustments to avoid triggers.
The approach may vary based on the severity and type of asthma, and it can include:
Long-term Control Medications
These are used regularly to maintain control of persistent asthma, reduce inflammation, and prevent symptoms.
- Inhaled Corticosteroids: Reduce airway inflammation and are considered the most effective long-term control medication for most people.
- Long-acting Beta Agonists (LABAs): Used in combination with inhaled corticosteroids, they help to keep the airways open.
- Leukotriene Modifiers: Oral medications that reduce airway inflammation and help control symptoms.
- Theophylline: A daily pill that helps keep the airways open by relaxing the muscles around the airways.
- Biologic Therapy: Targeted for severe asthma, these drugs target specific molecules or cells involved in the inflammatory process.
Quick-Relief (Rescue) Medications
Used to quickly relax and open the airways during an asthma attack.
- Short-acting Beta Agonists (SABAs): Inhaled drugs that are the first choice for quick relief of asthma symptoms.
- Anticholinergics: Inhaled medications that can help to quickly relieve asthma symptoms in certain individuals.
Lifestyle and Home Remedies
- Avoiding Triggers: Identifying and avoiding environmental triggers can help control asthma symptoms.
- Breathing Exercises: Can help to improve lung capacity and reduce asthma symptoms.
Healthcare providers often develop a personalized asthma action plan for their patients, detailing daily treatment, such as which medications to take and when, and how to handle worsening asthma or attacks.
For those with allergic asthma, treatments may also include allergy medications and immunotherapy (allergy shots) to reduce the body’s reaction to specific allergens.
Note: The goal of asthma treatment is to keep symptoms under control and prevent asthma attacks, allowing individuals to lead a normal, active life. Regular follow-ups with a healthcare provider are essential to adjust treatment as needed.
Types of Asthma
Asthma is categorized into several types based on factors such as triggers, severity, and the age at which it develops.
The main types include:
- Allergic Asthma (Extrinsic): Triggered by allergens such as pollen, pet dander, dust mites, and mold. It is often associated with hay fever and other allergies.
- Non-Allergic Asthma (Intrinsic): Triggered by factors not related to allergies, such as stress, exercise, cold air, smoke, or viral infections.
- Exercise-Induced Bronchoconstriction (EIB): Previously known as exercise-induced asthma, this occurs during or after exercise. It affects up to 90% of people with asthma and can also occur in people without chronic asthma.
- Cough-Variant Asthma (CVA): Characterized primarily by a dry, non-productive cough, either chronic or in response to specific triggers.
- Occupational Asthma: Triggered by inhaling fumes, gases, dust, or other potentially harmful substances while at work.
- Aspirin-Exacerbated Respiratory Disease (AERD): Worsening of asthma symptoms in response to aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs).
- Adult-Onset Asthma: Begins in adulthood and can be triggered by various factors, including allergies, respiratory infections, and hormonal changes.
- Severe Asthma: A type of asthma that is more difficult to control and often requires high doses of medications or specialized treatments.
- Childhood Asthma: Begins in childhood; its symptoms might improve or even disappear during adolescence, but can also persist into adulthood.
Note: Understanding the specific type of asthma can help in developing an effective management and treatment plan.
Asthma Triggers
Asthma triggers can vary widely among individuals, but common triggers include:
- Allergens: Such as pollen, dust mites, mold spores, pet dander, and cockroach droppings.
- Respiratory Infections: Including the common cold, flu, and sinus infections.
- Exercise: Particularly in cold, dry air.
- Air Pollutants and Irritants: Including smoke from tobacco or burning wood, strong odors from painting supplies or perfumes, air pollution, and occupational vapors.
- Weather Conditions: Cold air, changes in weather, and humid or windy days.
- Strong Emotions and Stress: Laughing, crying, or stress can lead to hyperventilation and narrowing of the airways.
- Medications: Aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), and beta-blockers can trigger asthma in some people.
- Food Additives: Sulfites and preservatives added to some types of foods and beverages might trigger asthma attacks.
- Gastroesophageal Reflux Disease (GERD): A condition in which stomach acids back up into the throat, which can worsen asthma symptoms.
- Hormonal Changes: In women, hormonal fluctuations during menstruation, pregnancy, or menopause can trigger asthma symptoms.
Note: Identifying and avoiding personal asthma triggers is a critical part of managing asthma effectively.
What is an Asthma Attack?
An asthma attack, also known as an asthma exacerbation, occurs when asthma symptoms significantly worsen due to the narrowing of the airways.
This narrowing is typically the result of inflammation and the tightening of muscles around the airways (bronchoconstriction). During an attack, the lining of the airways also produces excess mucus, further reducing airflow and making breathing difficult.
Symptoms
Symptoms of an asthma attack can include:
- Severe wheezing when breathing both in and out.
- Coughing that won’t stop.
- Very rapid breathing or difficulty speaking due to shortness of breath.
- Chest tightness or pressure.
- Extreme difficulty breathing or gasping for air.
- Feeling of anxiety or panic.
- Pale, sweaty face.
- Blue lips or fingernails, indicating oxygen levels in the blood are dangerously low (in severe cases).
Asthma attacks can be triggered by various factors, including exposure to asthma triggers like allergens, air pollution, cold air, exercise, stress, or respiratory infections.
The severity of attacks can vary from mild and manageable at home with quick-relief (rescue) inhalers to severe episodes that require immediate medical attention. Severe asthma attacks can be life-threatening and require emergency care to restore normal breathing.
Asthma Practice Questions
1. What is the definition of Asthma?
A respiratory disorder characterized by recurring episodes of paroxysmal dyspnea, wheezing on expiration or inspiration caused by constriction of the bronchi, coughing, and viscous mucoid bronchial secretions.
2. What does hyperreactivity of the airways lead to?
Bronchoconstriction, bronchospasm, mucosal swelling, and increased production of thick tenacious mucus.
3. What are the two types of asthma?
Extrinsic and intrinsic
4. What kind of asthma is extrinsic?
Type-one or allergenic asthma
5. What kind of asthma is intrinsic?
Type-two or non-allergenic asthma
6. What can cause the onset of extrinsic asthma?
Pollen, mold, dander, or different foods.
7. What can cause the onset of intrinsic asthma?
Stress, cold or dry air, smoke, anxiety, viruses, or infections.
8. What are the signs, symptoms, and observations of asthma?
Increased respiratory rate, work of breathing, heart rate, cardiac output, and blood pressure. The patient may also have a prolonged (forceful) expiration and a decreased peak expiratory flow rate.
9. What are the breath sounds of a patient with asthma?
Wheezing on expiration, and if heard on inspiration, it’s a more serious case of asthma.
10. What does it mean when you do not hear wheezes when listening to an asthma patient who is clearly in distress?
It means that there is no air movement, which is a serious case of asthma. This could be life-threatening and may require intubation and mechanical ventilation.
11. What ABG results are associated with asthma?
During a mild asthma attack, the pH may be increased with a decreased PaCO2 due to hyperventilation. During a moderate asthma attack, the pH may appear within the normal range along with hypoxemia. During a severe asthma attack, the pH is decreased, the PaO2 is severely decreased, and the PaCO2 is increased, resulting in respiratory failure.
12. What happens when mediators are released in asthma?
Bronchoconstriction, bronchospasm, pulmonary vasodilation, airway inflammation, and increased mucus production.
13. What does it mean if the PaCO2 rises drastically and suddenly during an asthma attack?
It likely means that the patient isn’t moving any air and may be going into respiratory failure. This is a very dangerous situation and may require intubation and mechanical ventilation.
14. What will that chest x-ray show of a patient with asthma?
You may see no significant changes, it may be slightly darkened, or you may see an increased lung capacity due to air trapping.
15. What happens to the systolic blood pressure during an asthma attack?
It will decrease during inspiration by 10-20 mmHg.
16. Which type of WBC increases during an asthma attack?
Eosinophils
17. What will the PFT test show for a patient with asthma?
Decreased airflow, low peak flows, and an increased residual volume. The FVC may be decreased due to air trapping, and the FEV1/FVC ratio is also decreased.
18. What should be the first treatment for asthma?
Prevention; avoid triggers if possible.
19. What are some medical treatments for patients with asthma?
The patient will undergo a preventative asthma action plan and immunotherapy.
20. What is pulsus paradoxus?
Pulsus paradoxus is a condition where there’s an exaggerated decrease in systolic blood pressure during inspiration by more than 10 mmHg.
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21. What is the first line of defense for asthma?
Maintenance with long-acting beta-2 agonists and inhaled corticosteroids.
22. What is the second line of defense for asthma?
Fast-acting Beta-2 agonists, such as albuterol, xopenex, etc., and anticholinergic medications like ipratropium bromide are also used.
23. What is the third line of defense for asthma?
Emergency oral and intravenous steroids.
24. What is the fourth line of defense for asthma?
Xanthine drugs (such as aminophylline and magnesium sulfate via IV) and Heliox.
25. What are some special medications used to treat asthma?
Leukotriene antagonist and Montelukast Sodium (Singulair)
26. What are some prophylactic medications used to treat asthma?
Cromolyn (Intal) and Nedocromil (Tilade)
27. When would you use Xolair (omalizumab) to treat asthma?
It can be used to treat patients who are 12 years of age and above. They must have moderate to severe persistent asthma, have asthma triggered by year-round allergens in the air, and continue to have asthma symptoms even though they are taking inhaled steroids.
28. When are continuous bronchodilator treatments needed to treat asthma?
In the emergency department, back-to-back continuous short-acting bronchodilators may be given to the patient to help alleviate bronchospasm.
29. When is a methacholine challenge test used?
A methacholine challenge test is performed to determine how reactive or responsive the lungs are to different asthma triggers in the environment. The test can help evaluate symptoms suggestive of asthma and help diagnose whether or not the patient has it.
30. What are the common symptoms of asthma?
Cough, chest tightness, shortness of breath, and wheezing.
31. What are the common asthma triggers?
Allergens, irritants, weather changes, viral or sinus infection, exercise, cold air, medications/food, and emotional anxiety.
32. What is an allergen?
They affect only people allergic to a specific substance.
33. What are the common asthma allergens?
Pollen, mold, animal dander, dust mites, and cockroach droppings.
34. What is an irritant?
They affect everyone if the dose is high enough.
35. What are some examples of irritants?
Tobacco smoke, wood smoke, chemicals in the air, ozone, perfume, household cleaners, cooking fumes, paint, and varnishes.
36. What are some occupational irritants?
Vapor, dust, gases, and fumes.
37. What are some other common causes of asthma?
Viral and sinus infections, exercise, reflux disease, medications (NSAIDS), beta-blockers, and emotional anxiety.
38. What are the types of medications that help with asthma symptoms?
Antihistamines, decongestants, anti-inflammatory agents, anti-leukotrienes, bronchodilators, and anticholinergics.
39. What three types of medications are used as anti-inflammatory agents?
Mast cell stabilizers, corticosteroids, and bronchodilators.
40. What are the classes of bronchodilators available for asthma?
Beta-agonists, methylxanthines, and anticholinergics.
41. What are methylxanthines?
Methylxanthines are a class of medications, including theophylline and caffeine, that are used primarily as bronchodilators to treat respiratory diseases. They help relax the muscles in the lungs and decrease the airways’ response to irritants.
42. What are rescue medications?
They are administered when a patient has symptoms of an asthma attack.
43. What are maintenance medications?
They are administered when a patient doesn’t have symptoms and are meant to help control the disease.
44. How do anticholinergics work?
Anticholinergics work by blocking the action of acetylcholine, a neurotransmitter involved in transmitting messages in the nervous system, which reduces muscle contractions in the airways.
45. What are the 6 goals for effective asthma management?
1) To prevent chronic and troublesome symptoms, (2) to maintain normal breathing, (3) to maintain normal activity levels, including exercise, (4) to prevent recurrent asthma flare-ups, (5) to minimize the need for emergency room, and (6) to provide optimal medication therapy with no or minimal effort.
46. What are the 4 categories of asthma?
(1) Mild intermittent, 2) mild persistent, 3) moderate persistent, and 4) severe persistent.
47. What are the rules of 2 for asthma medications that tell you that your asthma is not under control?
You use a rescue inhaler more than 2 times a week, you awaken at night with asthma symptoms more than 2 times a month, or you use more than 2 canisters a year of your rescue inhaler.
48. What are some examples of quick-relief medications?
Short-acting beta-2 agonists, inhaled anticholinergics, short-acting theophylline, and epinephrine.
49. What are some examples of long-term asthma medications?
Corticosteroids, tablets or syrup steroids, mast cell stabilizers, long-acting beta-2 agonists, sustained-release tablets, sustained-release methylxanthines, and anti-leukotrienes.
50. What is the difference between asthma and croup?
Asthma is a chronic condition characterized by airway inflammation and hyperactivity, leading to wheezing and difficulty breathing. Croup is an acute viral infection causing a distinctive “barking” cough and swelling in the upper airways, primarily affecting young children.
51. How do peak flow meters aid in asthma management?
A peak flow meter measures how well air moves out of the lungs. It helps monitor a person’s asthma severity and can indicate a pending asthma attack before symptoms worsen.
52. What role do immunomodulators play in asthma treatment?
Immunomodulators, such as omalizumab, modify the immune response and are used particularly in severe allergic asthma to decrease the frequency of asthma attacks.
53. What is the impact of obesity on asthma control?
Obesity can worsen asthma control due to increased inflammation and respiratory load, potentially leading to a greater need for medications and decreased overall lung function.
54. What is the significance of the FeNO test in asthma?
The fractional exhaled nitric oxide (FeNO) test measures the levels of nitric oxide in exhaled breath, which is a marker for eosinophilic airway inflammation, commonly found in asthma.
55. How does pregnancy affect asthma management?
Asthma management during pregnancy may require adjustments to minimize both maternal and fetal risks. Good asthma control is crucial to reduce the risk of complications such as pre-eclampsia and preterm birth.
56. What are the guidelines for asthma management during exercise?
Guidelines recommend pre-treatment with inhaled bronchodilators and warming up before exercise to prevent exercise-induced bronchospasm, which is common in people with asthma.
57. What is the role of spirometry in diagnosing asthma?
Spirometry is a test that measures the amount (volume) and/or speed (flow) of air that can be inhaled and exhaled. It is essential for diagnosing asthma and for assessing lung function over time.
58. What are the potential side effects of long-term use of inhaled corticosteroids?
Potential side effects include hoarseness, oral thrush, and, in some cases, an impact on growth in children, bone density, and possibly cataract formation.
59. How does environmental pollution affect asthma?
Environmental pollutants such as ozone, sulfur dioxide, and particulate matter can trigger asthma symptoms and exacerbate existing asthma conditions by increasing airway inflammation and sensitivity.
60. What are the principles of an asthma action plan?
An asthma action plan is a personalized management plan written by a healthcare provider that outlines daily management (such as which medications to take and when) and how to handle worsening asthma or attacks.
61. What are the indications for using systemic corticosteroids in asthma management?
Systemic corticosteroids are used for managing severe asthma exacerbations and for patients who do not respond adequately to inhaled corticosteroids and long-acting bronchodilators.
62. How do leukotriene receptor antagonists work in treating asthma?
Leukotriene receptor antagonists, such as montelukast, block the action of leukotrienes, chemicals in the immune system that contribute to inflammation, bronchoconstriction, airway edema, and mucus production in asthma.
63. What is the impact of psychological stress on asthma?
Psychological stress can exacerbate asthma symptoms and triggers. It may affect the immune system and increase inflammation, leading to more frequent or severe attacks.
64. What are the step-up and step-down approaches in asthma management?
The step-up approach involves increasing medication strength or number when asthma is not well-controlled. The step-down approach reduces medication when asthma is well-controlled to find the minimum therapy needed to maintain control.
65. What are the risks associated with undertreating asthma?
Undertreating asthma can lead to chronic inflammation, permanent airway damage, severe exacerbations, and, in extreme cases, fatal asthma attacks.
66. How is occupational asthma diagnosed and managed?
Occupational asthma is diagnosed by identifying a correlation between the workplace environment and asthma symptoms. Management includes avoiding the allergen or irritant and may involve medications similar to those used for other types of asthma.
67. What are the criteria for diagnosing severe asthma?
Severe asthma is diagnosed when symptoms persist despite high-dose inhaled corticosteroids combined with another controller medication and where the individual experiences frequent exacerbations and poor lung function.
68. What is the role of Vitamin D in asthma management?
Some studies suggest that Vitamin D can reduce the frequency of asthma attacks in individuals with a Vitamin D deficiency by improving immune function and reducing airway inflammation.
69. What is nocturnal asthma?
Nocturnal asthma is a type of asthma in which symptoms worsen at night, affecting sleep quality and overall respiratory function.
70. What strategies are used for asthma prevention in children?
Preventive strategies include avoiding exposure to known triggers, such as tobacco smoke, minimizing the use of heating and cooking appliances that pollute indoor air, and ensuring vaccinations are up to date to prevent respiratory infections that can trigger asthma episodes.
71. What is exercise-induced bronchoconstriction (EIB), and how is it managed?
Exercise-induced bronchoconstriction (EIB) occurs when airways tighten during or after exercise, causing difficulty in breathing. Management includes using pre-exercise inhaled bronchodilators, warming up prior to exercise, and wearing a mask in cold environments.
72. How does air temperature affect asthma symptoms?
Cold air can trigger asthma symptoms because it causes airway tightening. Hot and humid air can also worsen symptoms by increasing the amount of allergens like pollen and mold in the air, as well as irritants like ozone.
73. What is the significance of a written asthma action plan?
A written asthma action plan is crucial as it provides personalized guidelines prepared by healthcare providers for managing daily asthma care, recognizing early symptoms of exacerbation, and knowing specific steps to take during an asthma attack to prevent severe outcomes.
74. What is the impact of gastroesophageal reflux disease (GERD) on asthma?
GERD can exacerbate asthma symptoms, particularly cough and wheezing, by causing aspiration of stomach contents into the lungs or by a reflex mechanism that affects the airways when acid irritates the esophagus.
75. What is the strongest predisposing factor for asthma?
Atopy is the strongest predisposing factor for developing asthma. It refers to the genetic predisposition for the immunoglobulin E (IgE)-mediated response that occurs in allergic diseases.
76. What are the best and worst places to live with asthma?
The best places to live with asthma generally have clean air, low pollution levels, and a mild climate, while the worst are often cities with high pollution levels, extreme temperatures, and high pollen counts.
77. What are the vital signs of a patient with asthma?
The vital signs of a patient with asthma during an exacerbation typically include an increased respiratory rate, possibly an increased heart rate, and changes in blood pressure. Oxygen saturation may also decrease during a severe asthma attack. In cases of severe attacks, there might be signs of respiratory distress, such as using accessory muscles to breathe.
78. Is it possible to outgrow asthma?
Some children with asthma may experience fewer symptoms as they grow older, but asthma can persist into adulthood or return later in life.
79. When is medical gas therapy indicated to treat asthma?
Medical gas therapy, including oxygen therapy, is indicated for asthma when a patient exhibits signs of hypoxemia or severe respiratory distress. This treatment helps ensure adequate oxygenation and reduces the work of breathing during acute asthma exacerbations.
80. What is the difference between asthma and COPD?
Asthma is a reversible airway condition characterized by inflammation and hypersensitivity to triggers, while COPD is a progressive disease primarily caused by long-term exposure to irritants that lead to irreversible airway damage and obstruction.
Final Thoughts
Asthma remains a prevalent and challenging respiratory condition, impacting the lives of individuals across all age groups.
While there is currently no cure for asthma, effective management strategies, including medication and lifestyle changes, can help control symptoms and improve the quality of life for those affected.
Continued research and education are essential in advancing our understanding and treatment of asthma, ultimately striving toward better patient outcomes.
Written by:
John Landry is a registered respiratory therapist from Memphis, TN, and has a bachelor's degree in kinesiology. He enjoys using evidence-based research to help others breathe easier and live a healthier life.
References
- Faarc, Kacmarek Robert PhD Rrt, et al. Egan’s Fundamentals of Respiratory Care. 12th ed., Mosby, 2020.
- Clinical Manifestations and Assessment of Respiratory Disease. Mosby; 8th Edition, 2019.
- Hashmi MF, Tariq M, Cataletto ME. Asthma. [Updated 2023 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024.