
"Practical Tips" Series: Bronchial Asthma
by M. Al-Haj, MD, Germany
©Copyright by Semmelweis-Verlag, Germany
(Explore Issue: Volume 8, Number 6)
Definition / Etiology
Bronchial asthma is a disease of the lungs in which an obstructive ventilation disturbance of the respiratory passages evokes
a feeling of shortness of breath. The cause is a sharply elevated resistance to airflow in the airways. Despite its most strenuous
efforts, the respiratory musculature is unable to provide sufficient gas exchange. The result is a characteristic asthma attack, with spasms
of the bronchial musculature, edematous swelling of the bronchial wall and increased mucus secretion. In the initial stage, the
patient can be totally symptom-free for long periods of time in the intervals between the attacks. As the disease progresses, increased
mucus is secreted between attacks as well, which in part builds up in the airways and can then lead to secondary bacterial infections.
There are two forms of bronchial asthma from a genesis point of view:
- Non-allergic asthma (intrinsic asthma)
- Allergic asthma (extrinsic asthma)
Common to them both is a hypersensitivity of the bronchial system. However, in most cases, the two forms of asthma
are coupled with each other.
A prerequisite for non-allergic bronchial asthma is a genetic predisposition. Nonspecific stimuli such as cigarette smoke,
air pollution, medications, emotional factors such as shock, career or family problems, disturbed parent-child relationships but
also viral, bacterial or fungal infections can trigger asthma attacks. The attack can last from a few minutes to several hours; in the
life-threatening Status asthmaticus, it can persist for days. In these cases, immediate hospitalization is essential.
The pathogenesis of non-allergic asthma proceeds via the reflex secretion of acetylcholine. This causes the release
histamine from the mast cells of the bronchial wall. This results in immediate
contraction of the smooth bronchial musculature along
with overproduction of mucus. Here, the atopically inclined person reacts to environmental allergens with immediate production
of antibodies.
1020% of all people suffer from exogenous/allergic asthma. They react, for example, to pollen or dust mites with severe
overproduction of immunoglobulins (IgE reaction). Simplifying somewhat, the following reaction pattern unfolds: the allergen induces
a massive production of IgE antibodies. These bind to the surface of the mast cells in the bronchial mucous membrane and thereby
effect the release of histamine, which then results in an immediate contraction of the bronchial musculature.
Besides this immediate histamine-induced reaction, other mediators are involved in the so-called inflammatory
delayed reaction, which are ultimately responsible for the progressive hyperreactivity of the bronchial system. In the disease's
advanced stage, the victim reacts not only to the specific original allergen: nonspecific stimuli or infections suffice to provoke
asthmatic symptoms.
If not adequately treated, pulmonary emphysema not infrequently develops from bronchial asthma, characterized by
pneumoectasis with irreparable structural changes in the smallest broncheoles. Because to the perpetual hyperdistention of the
lungs and the extra work involved in breathing, these victims are recognizable by their rigid barrel-shaped thorax and
pronounced hunchback.