Hay fever is one of the most common allergies in Western industrialized countries and appears to be spreading from one generation to the next. According to the Robert Koch Institute, almost 15 percent of the German population is affected by a pollen allergy. According to University Hospital Zurich, the figure in Switzerland is as high as 25 percent.
Statistics and research indicate that the likelihood of developing hay fever increases due to factors such as air pollution, an unhealthy lifestyle, or excessive hygiene. In addition, there is a high probability that those affected will pass their allergies on to their offspring.
Contents
- What is hay fever?
- Typical symptoms and complaints associated with pollen allergy
- Cross-allergies associated with hay fever
- Why are more and more people developing hay fever?
- Diagnosing and treating hay fever
The allergy, whose effects can range from cold-like symptoms to allergic asthma, is triggered by the pollen of various grasses, grains, and trees. Their pollen floats in the air in the form of tiny particles, is inhaled, or reaches the mucous membranes of the eyes, mouth, and nose. There, it triggers an immediate immune response.
Watery eyes, a constantly runny nose, or asthma attacks can ruin the day for people with pollen allergies from spring through autumn. However, we are not entirely powerless against this “common ailment.” In addition to suppressing symptoms with medication, it is often possible to reduce the allergy itself through hyposensitization.
What is hay fever?
Hay fever is triggered by pollen. Pollen is a component of flower dust - it is the male genetic material with which female flowers are “pollinated.” Some flowering plants rely on bees and other insects to carry their pollen from flower to flower.
For allergy sufferers, the pollen that spreads exclusively through the wind is particularly problematic. To ensure the survival of their species, some trees, grasses, and shrubs release millions of pollen grains, which float in the air as microscopic particles and can spread hundreds of kilometers.
Not all plants bloom at the same time - alder and hazel, for example, bloom as early as March, while birch pollen and grasses follow later in spring. Various grasses and herbs even bloom into autumn. Fortunately, most people with pollen allergies are not allergic to all types of flower pollen.
They only have to deal with symptoms during part of the year. Anyone who has a runny nose all year round and also experiences symptoms in winter is probably more likely to suffer from allergic rhinitis, which can be triggered by a combination of dust, spores, animal allergens, and pollen. A pure pollen allergy only occurs seasonally.
Typical symptoms and complaints associated with pollen allergy
Hay fever is a type I allergy - meaning that symptoms occur practically immediately upon contact with the allergen. Even small amounts of pollen are enough to provoke the immune system of allergy sufferers.
The otherwise harmless pollen is perceived as a dangerous substance. This overreaction of the body's defenses causes the typical complaints associated with hay fever.
- Cold-like symptoms such as a blocked or runny nose or frequent sneezing are probably the most common. When the nose runs, it does not stop again quickly in more severe cases.
- If the allergy affects the bronchi and lower airways, it may manifest as coughing and audible wheezing in the lungs. Severe symptoms can include shortness of breath and allergic asthma.
- Watery and itchy eyes are also very common. They are often accompanied by significant redness of the conjunctiva. The urge to rub the eyes can be very strong. However, this only makes the symptoms worse. It may be helpful to treat the eyes with a special eye-wash solution to flush out allergens. Otherwise, they are gradually removed with the tear fluid.
- Headaches, fatigue, and difficulty concentrating also occur in connection with hay fever. In some people, the allergy triggers migraine symptoms. Sleep disorders and increased sensitivity of the eyes to light have also been linked to hay fever.
- More rarely, a so-called angioedema may develop. This is swelling of the skin or mucous membranes caused by fluid accumulation. It may be accompanied by itching and the formation of hives and eczema. The same applies here: Avoid scratching if possible and cool the affected area instead. Medical assistance should be sought in cases of severe angioedema affecting the head and neck.
A pollen allergy may become weaker on its own over the course of a person's life. However, it may also become stronger - particularly in severe cases, the development of long-term effects such as allergic asthma cannot be ruled out if the allergy remains untreated. Treatment options for hay fever are discussed further below.
Cross-allergies associated with hay fever
Cross-allergies are said to occur when different substances trigger the same allergic reactions. The different substances are so similar that the immune system does not distinguish between them.
People with pollen allergies relatively often suffer from cross-allergies associated with fruit or nuts. For example, people who cannot tolerate apples are often also allergic to birch pollen. However, cross-allergies involving birch also occur with nuts, almonds, peaches, and other fruit.
Some vegetables, such as celery or carrots, can trigger a cross-reaction with herbs such as mugwort or spice plants such as pepper.
Cross-allergies with substances that have little or no similarity to one another occur less frequently. For example, people who are allergic to grasses may sometimes be unable to tolerate peas or other legumes. In rare cases, cross-reactions with latex have even been reported. The latter were triggered by allergies to fruit.
When reactions to food occur, it is often possible to deactivate the relevant allergen by heating it. Thus, people who cannot tolerate raw apples can often eat them as previously cooked applesauce or as a baked apple at Christmas. However, in cases of severe food allergies, it is advisable to avoid contact with the allergen completely.
Why are more and more people developing hay fever?
Over the past few decades, the number of people with pollen allergies in Germany and other Western industrialized nations has increased significantly, while the figures in Eastern Europe and the Balkans have remained virtually stagnant. More and more researchers are linking this increase to factors such as diet, lifestyle, and air pollution.
Since children in cities are much more likely to develop hay fever than children who grew up in rural areas, links with hygiene conditions and air quality are obvious.
The so-called hygiene hypothesis suggests that children whose immune systems can become accustomed to various germs at an early age have better protection against allergies such as hay fever. Children “in the countryside” come into contact with various germs much more frequently.
Scientists are focusing primarily on bacteria that contain the toxin endotoxin. Endotoxins can cause fever and inflammation, but are also thought to trigger immune reactions similar to hyposensitization against allergens. The immune system therefore learns to tolerate allergens such as pollen, animal proteins, or dust.
Factors such as air pollution from particulate matter, exhaust fumes, or smoke appear to affect the severity of allergies. Hay fever also tends to occur more frequently in areas with high levels of particulate matter. It is suspected that various pollutants in the air make the mucous membranes of the airways more sensitive to allergens.
Diagnosing and treating hay fever
If you notice symptoms that indicate hay fever, it is best to consult a doctor you trust. General practitioners, pediatricians, or dermatologists are often also allergists and offer allergy tests at their practices. It is important to first test the exact triggers of the hay fever and the severity of the immune reaction in order to plan further treatment.
There are various allergy tests. The prick test is often used to identify pollen allergies. This is a skin test performed on the test person's forearm or back. It is important to have a larger area of skin available, as sections are marked on the skin before the test.
A different allergen in a neutral liquid is dripped onto each section - the drop is then pierced with a sterile needle. The needle scratches the top layer of skin so that a small amount of the allergen can penetrate the tissue. The local reaction in each area (redness, hives, etc.) indicates whether an allergy is present.
Once it is known which pollen triggers your hay fever, hyposensitization can be considered. This is a longer process in which small amounts of an allergen are taken regularly. By gradually increasing the dose, the immune system can become accustomed to the allergen and react with a significantly weaker immune response.
Allergies such as hay fever can often be reduced to the point where they no longer interfere with everyday life. Hyposensitization usually takes between 12 and 24 months and is most successful when carried out at a young age. However, adults also have a good chance of alleviating their hay fever.
Allergic symptoms can also be suppressed with medication. However, medication cannot cure them. In cases of hay fever, medications counter symptoms such as swelling of the mucous membranes.
It may therefore be advisable to take medication for severe hay fever while the relevant pollen is in the air. In any case, seek medical advice if you suffer from severe hay fever.
