Bronchial asthma is a very widespread medical condition with many possible causes, and it is defined as a chronic inflammatory disease of the airways. In allergic asthma, symptoms are provoked by contact with an allergen to which the immune system is hypersensitive. On the other hand, non-allergic asthma is not related to any allergic reaction and it can be triggered by other factors such as stress, cold and dry air, smoking, and respiratory infection.
Regardless of the cause, the pathophysiology and symptoms of an asthma attack are similar. The main pathological processes during an asthma attack include bronchoconstriction (narrowing of the bronchi), increased mucus secretion, and inflammation of the airways. This manifests as cough, shortness of breath, and wheezing of variable severity.
Even though allergic asthma is caused by a specific allergen, attacks can be triggered by various physical and chemical (mostly inhalational) factors in both allergic and non-allergic asthma. Here we examine some of these possible triggers.
Epidemiological data state that about 25-30 percent of asthmatic patients are smokers. Likewise, smokers have an increased risk of developing non-allergic asthma due to harmful effect of cigarette toxins on bronchial mucosa. Studies suggest that besides being more susceptible to developing asthma, smokers also have poor control of asthma because of primary smoking. Cigarette toxins lower the effects of inhalational corticosteroids, which are currently the most effective option for long-term asthma management.
Although not much research has been done on second-hand smoke and its effects on asthmatic patients, there is some evidence that children are the most affected age group. In fact, maternal smoking has been proven to decrease lung function in children, especially during the first year of life.
Inhalation of different agents present in the workplace can cause or aggravate symptoms of asthma. However, it can be characterized as occupational asthma only if asthma is caused by those agents. This is because up to 15 percent of asthmatic patients report worsening of their symptoms at work and relief when they are off from work, and in most of them, agents in the workplace just worsen their already existing asthma. Farmers, bakers, chemists, drug manufacturers, healthcare workers, carpenters, pharmacists, and poultry workers are among the many professions that can be affected by this condition.
If occupational asthma is suspected, different tests are performed with the aim to prove the causative factor. A worker with diagnosed occupational asthma needs to be transferred to another workplace, which can sometimes completely eliminate signs of the disease.
Interestingly, while smoking cigarettes has been shown to trigger asthma, the effects of marijuana smoking on asthma are controversial. Some studies suggest that marijuana worsens coughing and wheezing in asthmatic patients, while others conclude that cannabis even dilated the bronchi. Of 34 studies assessed in one recent high-quality literature review, 33 studies showed bronchodilating effects of marijuana right after inhalation, but bad long term-effects, including many respiratory complications, such as bronchoconstriction, increased secretion, wheezing and cough.
Another important characteristic of asthma is that its symptoms are reversible until the pathological process causes permanent changes to the bronchi and lung tissue. After that, the patient is dealing with Chronic Obstructive Pulmonary Disease (COPD), which is a serious and progressive condition.
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