Introduction
Some of the materials covered in this course include the respiratory system and its diseases, such as asthma. When I was young, I had a friend called Brian, who always walked with the asthma inhaler. Other children used to make fun of him when he had asthma attacks, and I felt sorry for him. Besides, he could not join us in playing football as exercising would worsen his illness. By then, we were young and did not understand what Brian was experiencing. I chose this condition to understand the etiology, symptoms, and how best Brian would have managed the ailment.
Asthma is a chronic inflammatory disease of the airways, making people experience breathing difficulties and have challenges in performing some physical activities. According to the Centers for Disease Control and Prevention [CDC] (2020), there are over 24 million asthmatic cases, and there is a higher prevalence in females. In terms of ethnicity, there is a higher prevalence of the condition among African Americans. It is hard to tell if someone has the illness, especially for children under five years (CDC, 2020). Therefore, it is advised that one should go for a medical checkup to be sure.
Etiology of Asthma
The illness can be grouped depending on the causative agent. Allergic or extrinsic asthma is triggered by common allergens such as pollen, dust, food, pet dander, and mold. Nonallergic or intrinsic asthma is due to irritants present in the air, and they include perfumes, air fresheners, cigarette smoke, air pollution, cold air, burning wood, or household cleaning reagents. Occupational asthma happens at workplaces, and dust, gases, fumes, animal proteins, rubber latex, industrial chemicals, and dyes activate it. Exercise-induced asthma is due to vigorous undertakings such as going to the gym. It ensues within a few minutes after starting an exercise and can last up to 15 minutes after the workout. Aspirin-exacerbated respiratory disease (AERD) is a severe form of asthma triggered by nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin, ibuprofen, or naproxen. Another type is nocturnal asthma, which is due to heartburns, dust mites, and pet dander.
Pathophysiology
The inflammatory response is central in the pathophysiology of asthma, and there are early and late asthma responses. On exposure to the trigger, the resident airway mast cells are triggered, causing the formation of crosslinks of immunoglobulin E (IgE) on the mast cell surface. This stimulates histamine production, which prompts the release of leukotrienes and prostaglandins, among other enzymes. Mast cells also release cytokines, which signal other inflammatory cells to the lungs. Histamine binds to the H1 receptors present on the smooth muscles of the bronchi, leading to bronchospasm and, eventually, wheezing (Lumb & Thomas, 2020). It also binds to other H1 receptors to increase vascular permeability. Mucous secretion is increased when histamine acts on H2 receptors. These events occur within minutes of exposure to the allergen; hence, it is referred to as the early asthmatic response.
The late asthmatic response occurs after several hours, and the delay is because of the presence of inflammatory cells and the continued inflammatory response. The important inflammatory cells in this phase are the T helper cells. The allergen antigen activates these cells, and they secrete several cytokines responsible for maintaining and enhancing the inflammatory response. Besides, the released cytokines attract other inflammatory cells such as eosinophils and master cells, which also produce cytokines, and consequently, augment the cellular and inflammatory response.
The pathophysiology is a bit different in patients with exercise-induced bronchoconstriction (EIB) without asthma, and it is related to inhalation of cold air. The air has a low moisture content, and when it reaches the bronchi, it absorbs water from the bronchial wall, leading to dehydration. The airway surface cells become hyperosmotic and draw water from the surrounding cells (Aggarwal et al., 2018). The changes in cell volume stimulate the inflammatory response. In asthma cases, there is increased ventilation of airways when a patient is exercising, and water is lost via evaporation. It causes dehydration of the airway surface, and consequently, the smooth muscles start to contract. The osmotic changes trigger mast cell degranulation, which releases inflammatory mediators.
Signs and Symptoms of Asthma
Patients’ common symptom is wheezing, whereby there is a production of a scratchy sound when breathing. Other symptoms are pain in the chest, chest tightness, shortness of breath, chronic cough, and sleeping difficulties. These symptoms are referred to as asthma attacks because, at one point, the patient is fine, and on exposure to the trigger agents, the symptoms flare up. The symptoms vary and can be moderate or severe and may happen daily or occasionally.
Several tests can be done to confirm if the symptoms are a result of asthma. Pulmonary function tests determine the rate of inhalation or exhalation at maximum effort. Broncho-provocation tests determine the response of the airways to specific substances. The fractional exhaled nitric oxide (FeNO) tests measure nitric oxide levels in a patient’s breath; increased levels indicate inflammation of the lungs. Most of the tests can be done during spirometry, and results are obtained within a short time. Besides, imaging techniques such as x-rays help identify abnormalities in the respiratory system and their magnitude and inform the extra tests (Harrison & Fauci, 2009). However, this technique is not sufficient to provide a specific diagnosis.
Treatment
Prevention
There is no method of preventing a person from developing asthma. However, asthmatic patients can circumvent asthma attacks through several means. First, they should identify the allergens, which they respond to, and evade them. This is because, without the trigger, a person cannot experience asthma flare-ups. Second, they should adhere to the doctor’s prescribed asthma action strategy as asthma is a persistent illness, and the approach will decrease needless healthcare use (Zahran et al., 2018). Moreover, the patients should be vaccinated against diseases such as influenza, which can initiate asthma. The patients should be in a position to identify and treat the ailment as early as possible. Also, they should immediately stop the activity they were engaged in as it may have been the trigger.
Diet and Health
Asthma patients do not require a special diet, but some foods may increase their lung function and better respond to asthma attacks. Obese patients are at a high risk of developing asthma, and it is difficult to treat asthma in overweight persons. Therefore, a person should have a healthy, balanced diet and maintain a good body weight for management ease. Patients should also take foods rich in vitamin A, D, and magnesium. Bananas are rich in potassium and antioxidants; hence they improve lung function. However, they should avoid allergic foods such as animal proteins, wheat, treat nuts, and shellfish. Also, foods producing or causing gas should be avoided as the gas presses on the diaphragm, leading to chest tightness and eventually triggers asthma flare-ups.
Medication
Besides following the prevention steps, medication is necessary to control the symptoms. There are several medications, and each has a different mechanism of action, targeting a specific point of the asthma pathophysiology. The drugs can be either quick-relief medications or long-term treatments. Short-acting beta-agonists such as albuterol and levalbuterol are inhaled and act within minutes to ease the symptoms of an asthma attack. Anticholinergic agents such as tiotropium and ipratropium are also quick-acting. They prevent acetylcholine from excreting high amounts of mucus and from causing contraction of smooth muscles. Oral and intravenous corticosteroids help to relieve the inflammation, but they have side effects when used for long.
Long-acting drugs include inhaled corticosteroids such as fluticasone propionate. These drugs are administered twice a day for several weeks to attain maximum benefit. They can be used in high doses in cases of severe asthma attacks. Another medication is theophylline, a pill taken daily to relax the bronchial smooth muscles and keep the airway open. It is not a common drug, and its downside is that it requires regular blood tests. There are also immunomodulatory drugs such as Omalizumab, which prevent IgEs from binding to mast cells; hence there is no inflammatory response. The drug is administered via the subcutaneous route every two to four weeks.
In conclusion, asthma is a chronic condition affecting many children globally, and it is triggered by allergens such as dust, pollen, animal proteins, among others. Persons with chest pains, difficulties in breathing, and producing wheezing sounds are highly likely to suffer from asthma and should visit a doctor for a checkup. The condition can be prevented by avoiding the asthma triggers, maintaining a healthy lifestyle, and observing the doctor’s asthma action plan.
References
Aggarwal, B., Mulgirigama, A., & Berend, N. (2018). Exercise-induced bronchoconstriction: Prevalence, pathophysiology, patient impact, diagnosis, and management. NPJ Primary Care Respiratory Medicine, 28(1), 1-8. Web.
Centers for Disease Control and Prevention. (2020). Most recent national asthma data. Web.
Harrison, T. R., & Fauci, A. S. (2009). Harrison’s manual of medicine. McGraw-Hill.
Lumb, A. B., & Thomas, C. R. (2020). Nunn’s applied respiratory physiology eBook. Elsevier.
Zahran, H. S., Bailey, C. M., Damon, S. A., Garbe, P. L., & Breysse, P. N. (2018). Vital signs: Asthma in children—United States, 2001–2016. Web.
Appendix A
National Demographic Information of 2018 for CDC (2020) ’s Asthma Data
