Description

Asthma is a longstanding condition that involving the functioning of airways in the lungs and is one of the respiratory disorders. The airways become narrow, swells and produce mucus which then blocks air supply making it hard to breath and prompts wheezing, coughing and breath shortness. While for some individuals asthma is a minor annoyance, it is a main problem for some people and restricts their daily activities due to asthmatic attacks. Current science and medication have not been able to cure the condition but it is commonly controlled with the right medication. In that asthma changes over time from mild to moderate to severe, it is significant for one to seek medical attention however mild it may look. The medication is adjusted as the condition changes and this is significant for effective control of the disease.

Epidemiology

Asthma is the utmost common non-communicable disease and has been ranked 16^th as a principal cause of incapacity and 28^th as the leading cause of disease burden. Currently, an estimated 300 million people live with asthma globally and this number is projected to rise to 100 million by 2025. However, the prevalence, mortality and severity vary with geographical location to a large extent. While the asthma prevalence is high in the developed countries, the highest mortality is within the low-middle income countries. Prevalence and incidence patterns are also different between children and adults. Asthma often begin in infancy but can occur anytime. While prevalence is high in children, mortality and asthma related health use are high in adults. The prevalence also differs by sex with pre-pubertal boys having a higher prevalence rate than girls the same age. In adulthood the trend reverses and women have a higher asthma burden than men. Asthma morbidity is increasing among aged adults having increased by 5.7% in 2018. The increase was associated with mold, clinical comorbidities and financial barriers

Common causes

There is no definitive cause of asthma but scientists and researchers have identified that there are various factors that can trigger the disease including

• Hygiene hypothesis: Babies not exposed to enough bacteria in early childhood have an immune system not strong enough to fight asthma.
• Allergen exposure: Frequent exposure to possible irritants and allergens increases the risk of developing the disease
• Viral infections history: People who had viral infections as children have a high likelihood of developing asthma

• Smoking: Cigarettes smokers are more likely to develop asthma
• Occupational exposure: Exposure to chemicals and dusts such as vapor, chemical gasses and molds can develop asthma for the initial time as adults.

Risk factors

• Obesity: The extra weight causes a low-grade inflammation in the body thus increasing asthma risk.
• Family history: If parents have asthma, children are three to six times more likely to acquire asthma as compared to children whose parents are asthma free.
• Air pollution: Exposure to polluted air as a result of smog surges the asthma risk. Urban dwellers thus have a higher risk of asthma as compared to rural dwellers.
• Allergies: Having an allergic problem such as eczema is a risk factor in the asthma development.
• Extreme weather conditions: Extreme conditions such as low temperatures and high humidity can trigger asthma.

Clinical manifestations

Clinical manifestations vary from individual to the other in the case of asthma and such manifestations vary with time. Th symptoms are commonly worse at night and resolves with the use of an inhaler or reliever medication. In extreme cases, the manifestation can worse within hours from mild to severe leading to an attack which requires advanced medication to relieve. The most common symptoms and signs of asthma include

• Recurring episodes of wheezing
• Difficulty breathing
• Chest stiffness or pain,
• Coughing
• Shortness of breath

Diagnosis

• Spirometry: This is used for patients older than five years. It determines how well the lungs are working by breathing out in a tube connected to a spirometer. It records how fast one exhales and the volume of air. If measurements are below normal range, it may indicate one has asthma. The doctor then asks one to inhale an asthma drug and repeats the test. If results show an improvement, then asthma is diagnosed.

• Challenge test: if the spirometry results are normal, a challenge test can be used to trigger asthma symptoms. The patient inhales a substance that makes the airwaves narrow in asthmatic patients. If the symptoms show, then asthma is diagnosed.
• Exhaled nitric oxide test: this involves the patient breathing into a tube connected to a machine that determines the level of oxide gas in the breath. The body normally produces oxide gas but high levels of the gas can indicate an inflammation of the air waves.
• Ancillary tests: Ancillary tests such as chest radiography and skin prick test help rule out the presence of other conditions such as environmental allergies, lung cancer, heart failure or bronchiectasis among others. The absence of conditions that have similar clinical manifestation as asthma is an indication of asthma presence.

References

Cockcroft, D. W. (2018, February). Environmental causes of asthma. In Seminars in respiratory and critical care medicine (Vol. 39, No. 01, pp. 012-018). Thieme Medical Publishers.

Dalibalta, S., Samara, F., Qadri, H., & Adouchana, H. (2018). Potential causes of asthma in the United Arab Emirates: Drawing insights from the Arabian Gulf. Reviews on environmental health, 33(2), 205-212.

Dharmage, S., Perret, J., & Custovic, A. (2019). Epidemiology of Asthma in Children and Adults. Frontiers In Pediatrics, 7. doi: 10.3389/fped.2019.00246

Hsu, J., Chen, J., & Mirabelli, M. C. (2018). Asthma morbidity, comorbidities, and modifiable factors among older adults. The Journal of Allergy and Clinical Immunology: In Practice, 6(1), 236-243.

McCracken, J. L., Veeranki, S. P., Ameredes, B. T., & Calhoun, W. J. (2017). Diagnosis and management of asthma in adults: a review. Jama, 318(3), 279-290.

Peloza, D., Evans, M. D., Gangnon, R. E., Gern, J. E., Lemanske, R. F., & Jackson, D. J. (2019). Early Life Risk Factors for Asthma at Early Adulthood. Journal of Allergy and Clinical Immunology, 143(2), AB78.