Causes, development and risk factors | Bronchial asthma

Causes, development and risk factors

Asthma is a repeated and sudden narrowing (obstruction) of the airways. An asthma attack can be triggered by various stimuli, which in a healthy lung have no consequences, but in an asthmatic an inflammatory reaction of the bronchial mucosa can be triggered. The mucous membrane swells and excretes more viscous mucus.

The bronchial tubes are thus mucous and constricted. In addition, the muscles of the smaller airways contract cramp-like, which makes breathing even more difficult. The oxygen supply to the lungs and thus to the body deteriorates; in extreme cases, a life-threatening condition can occur.

The development of bronchial asthma is a process influenced by many factors, in which environmental factors as well as genetic predispositions are involved. A distinction is made between exogenous allergic asthma and non-allergic asthma. Mixed forms are frequent.

Exogenous-allergic asthma is based on a malfunctioning response of the immune system. Possible allergens are: House dust mites, molds, animal hairs and scales, flower pollen and occupational allergens, such as flour for the baker. Non-allergic asthma is caused by a variety of factors where the immune system is not mobilised: physical exertion, cold air, sometimes warm and humid air, stress and emotions (laughter, crying, anxiety).

However, in most cases both forms occur together, as the constant inflammation of the respiratory tract in allergic asthma, for example, leads to bronchial hyperreactivity, which means that even the smallest stimuli such as smoke, perfume or cold air cause sensitivity and the mucous membrane reacts in the manner described above. Other special forms are exertion-induced asthma (stress-induced asthma), which usually occurs in the relaxation phase after physical exertion, and drug-induced asthma, mainly triggered by painkillers containing acetylsalicylic acid – ASS (aspirin) for short (a component of most headache tablets). In allergic asthma, a very specific dysregulation of the immune response (the body’s own defence reaction) takes place, which is directed against substances that actually do not pose any danger to the body.

In addition, most asthmatics have an increased blood level of IgE (immunoglobulin E). IgE is a special antibody of the immune system that acts as a messenger in the body to mediate an allergic reaction. At the beginning of the disease the triggering allergen to which the body reacts is sometimes still detectable.

In most cases, however, more and more triggering allergens are added over the course of time, which is called an expansion of the allergy spectrum. The original stimulus is no longer detectable and the avoidance of the triggering allergens becomes more and more difficult. For example, one must not only give up a pet, but gradually also spring walks and perfume.

Psychological factors also play a role. On the one hand, they can influence the extent of the disease, on the other hand they play an important role in coping with the disease. Patients with bronchial asthma often have other diseases, which are counted among the atopic clinical pictures.

Atopy is a genetically based readiness of the organism to react to various natural or artificial environmental stimuli with an exuberant immune response. Besides bronchial asthma, atopic diseases also include neurodermatitis or “hay fever“, for example. If the parents have atopic diseases, the risk of a child suffering from asthma is up to 50% higher.

The role of stress in the development of asthma has long been a very controversial topic. Nowadays, it is generally believed that stress in the form of psychological conflicts is not a cause of asthma. Nevertheless, it is certainly true that stress can have an additional reinforcing effect on the development of asthma.

However, a distinction must also be made between physical (i.e. physical) and psychological stress. A clearly defined form of asthma is exertional asthma, i.e. it occurs during physical exertion, often especially during physical stress in cold air. Acute mental stress often leads to increased breathing (hyperventilation), which in the long term can make breathing more difficult.

However, other factors must also be taken into account if an asthma illness is to develop. In many cases, however, several factors such as cold, genetics, pollen and other environmental influences in combination play a decisive role in the development of asthma. Asthma can be caused by a variety of factors.

One of these is medication, especially so-called NSAIDs (non-steroidal anti-inflammatory drugs), such as Aspirin® or ibuprofen. This form of asthma is also known as analgesic asthma. The complete mechanisms behind this trigger are not yet fully understood.

The most common assumption is that long-term use of, for example, aspirin or ibuprofen causes a shift in the balance between two important messenger substances. One is prostaglandin E2, which dilates the airways and is only produced to a reduced extent by aspirin. The other substance is leukotrienes, which cause the airways to contract and are produced in greater quantities if aspirin is taken for a longer period of time.

This shifts the balance between these two substances towards leukotrienes and leads to an increased narrowing of the airways. For this reason, leukotriene antagonists are also commonly used in therapy, as they inhibit precisely the leukotrienes. The form of analgesic asthma is often preceded by a chronic obstructive pulmonary disease, i.e. COPD.

Asthma can be caused by a variety of factors. Whether mould is considered to be its own cause has not yet been finally clarified. If there is an allergy to a type of mould, this can contribute to the development of asthma.

In addition, studies have shown that a long-term stay in damp rooms promotes the development of asthma. Therefore, when mould is discovered in an apartment, a renovation should always be carried out. A simple cold per se cannot lead to asthma.

Rather, a cold can intensify the symptoms of an already existing form of asthma, since the cold also weakens the respiratory tract and is attacked by viruses. As a result, an increased inflammatory process takes place in the lungs and the shortness of breath and coughing can become worse. A cold can also trigger an acute asthma attack with chest tightness and shortness of breath. For this reason, a doctor should always be consulted in the presence of an asthma illness and an additional cold.