Causes, diagnosis, and treatment
What is asthma actually?
Bronchial asthma is a chronic, i.e. persistent, inflammatory disease of the respiratory tract. The airways (bronchi) react hypersensitively to certain stimuli and are temporarily narrowed. Doctors speak of bronchial hyperresponsiveness. Typical symptoms of asthma are:
- Chest tightness
- Shortness of breath Dyspnea, especially at night or early in the morning
Every twentieth adult and every tenth child suffer from asthma. It is the most common chronic disease in childhood. Why some people develop asthma and others do not is not fully understood. It is known that both hereditary and environmental factors play a role. Depending on the trigger, the following forms of asthma can be distinguished:
- Allergic asthma
- Non-allergic asthma
- Mixed forms
Non-allergic (intrinsic) asthma
In non-allergic asthma, immune defense reactions also occur, however these are not caused by allergens, but by other triggers such as viral infections, drugs, chemicals, or pollutants.
Often there are mixed forms between allergic and non-allergic asthma. A distinction is not always easy, because the affected persons usually react equally to non-specific triggers, such as cold air, fog, cigarette smoke, or strong scents, with asthmatic symptoms. These triggers don’t cause the asthma, they merely set it off.
Where does asthma occur?
Where does asthma occur?
Facts and figures
Asthma is a worldwide health problem affecting people in low- and middle-income countries as well as in western high-income countries. According to the Global Asthma Report 2018, asthma is estimated to affect as many as 339 million people worldwide.
Asthma generally tends to affect more women than men. In Europe, there are nearly 10 million asthmatics below the age of 45. Around 10% of adult asthmatics suffer from severe asthma, which is difficult to treat. Asthma can affect people of any age, but occurs predominantly in childhood and is also the most common chronic disease in children.
How is asthma diagnosed?
Doctors usually identify the first indications of asthma from patients’ description of the typical symptoms and the medical history. If the suspicion is confirmed during the physical examination, pulmonary function diagnostics is performed. One of the tests is to ascertain how much air passes through the bronchi. This can be measured using the following methods:
Peak flow meter
Peak flow measurement can be done at home with the so-called peak flow meter. This determines the Peak Expiratory Flow (PEF), i.e. the maximum air flow from the lungs.
Spirometry (“small lung function test”)
Spirometry is used to measure lung or respiratory volume and air flow velocity and can only be performed by a physician. During the examination, the patient breathes into the spirometer through a mouthpiece. The nose is closed with a clamp.
Body plethysmography (“large lung function”)
Body plethysmography is usually performed by a specialist. In this lung function test, the patient sits in a special glass cabin. This supplements spirometry by determining the complete lung volume and airway resistance, providing the physician with further diagnostic information especially for patients who have difficulties in performing spirometry.
Stress or provocation test
Patients are often free of symptoms when they visit their doctor. Physicians therefore have the possibility to deliberately trigger the narrowing of the airways through different stimuli, e.g. physical stress or inhalation of histamine, in order to test the level of irritability in the airways (hyperresponsiveness).
In patients with respiratory problems and constricted airways (determined by spirometry or PEF), asthma testing is used to examine whether this constriction can be treated through medication (lysis). The patient is given a bronchodilator medication (e.g. salbutamol) before a new spirometry is performed. The drug typically improves values in asthmatics.
Nitric oxide measurement (FeNO)
Asthma is an inflammation of the respiratory tract. However, pulmonary function measurements allow only few conclusions to be drawn about the extent of the underlying inflammatory reaction. A measure of respiratory inflammation is the amount of nitric oxide (NO) in the exhaled breath (FeNO). In FeNO testing, the patient breathes into a measuring device through a mouthpiece. The measurement is quick, simple and stress-free. It can be performed in the doctor’s office or at home.
How is asthma treated?
How is asthma treated?
Despite intensive research, asthma is not curable. Nevertheless, the disease is now effectively treatable with medication.
Preventive measures include not smoking, avoiding allergy triggers and exercising regularly.
The goal of asthma treatment is to achieve the best possible asthma control with the lowest possible dose of medication. If persistent asthma symptoms make regular therapy necessary, inhaled corticosteroids form the basis of long-term therapy, because they treat the underlying inflammation that is the cause of the disease (DGP – German Respiratory Society – asthma guideline). Anti-inflammatory drugs must be taken regularly and for longer periods of time, because the hypersensitivity of the bronchial tubes only abates slowly. The most effective anti-inflammatory agent is cortisone. This is usually inhaled as a spray or powder. In this way, it quickly reaches the desired site of action, i.e. gets directly into the respiratory tract. In the case of severe asthma or asthma attacks, it is sometimes necessary to resort to cortisone tablets. Rapid-acting beta-sympathomimetics that expand the bronchi quickly and reliably can help as emergency medication for sudden shortness of breath.
Your doctor will discuss with you which medications are most effective for you. The therapy may have to be adapted and changed depending on the season or your state of health.
The cause of allergic or extrinsic asthma is, as the name suggests, an allergy. In the case of an allergy, the body’s own immune system reacts excessively strongly to inherently harmless substances. Such allergy triggers or allergens can be, for example:
- blossom/grass/tree pollen
- animal hair
- nuts or
- dust mites
The allergens trigger a so-called allergic early reaction in the body, which is associated with the increased production of immunoglobulin E (IgE). An elevated IgE level is detectable in the blood. The subsequent late allergic reaction can develop into a chronic inflammation and cause asthma symptoms. A distinction is made between seasonal asthma and non-seasonal asthma.
Seasonal allergic asthma
This type of asthma is caused by a pollen allergy. Depending on the pollen flight, the pollen occurs only during a certain season. Outside the pollen season, seasonal asthmatics have no symptoms and lung function returns to normal.
Non-seasonal allergic asthma
These asthmatics have symptoms all year round, e.g. due to a house dust mite allergy, mold infestation, or animal hair.
How can FeNO help me manage my asthma?
Asthma is a complex disease characterized by chronic inflammation of the airways. Different diagnostic methods can help to diagnose and characterize asthma. A newer method is FeNO measurement. This is particularly useful in the case of allergic asthma and enables the detection of an allergic inflammation of the lower respiratory tract.
Nitric oxide (NO), which is measured in the exhaled breath during this test, is produced by an allergic inflammation of the respiratory tract. There is a correlation between the concentration of NO in exhaled breath and the extent of respiratory inflammation. The higher the NO content, the more severe the inflammation.
FeNO measurement not only serves the physician as a helpful method to diagnose asthma. It can also help you to manage your disease.
Lungenärzte im Netz: https://www.lungenaerzte-im-netz.de/krankheiten/asthma-bronchiale/
Deutsch Atemwegsliga e.V.: https://www.atemwegsliga.de
The Global Asthma Network: Global Asthma Report 2018 http://www.globalasthmareport.org/Global%20Asthma%20Report%202018.pdf
Lunge und Gesundheit in Europa- Fakten und Zahlen: https://www.erswhitebook.org/