hay fever

Hayfever: description

Every fifth person in Germany suffers from hay fever. It is the most common allergy. As with all allergies, the immune system of the body reacts hayfever overly harmless substances – in this case not on hay, as the name suggests, but on proteins of pollen in the air (such as grass and tree pollen).

This is why hay fever is also referred to as pollen allergy, pollinosis or seasonal allergic rhinitis (= seasonal allergic rhinitis, allergic rhinitis). Seasonally, because the different pollen, which can cause hay fever, not in the year, but only during the flowering period of the respective plants are present in the air. Thus, the hay fever symptoms occur only in certain months of the year.

If the symptoms occur year round, it is probably not hay fever, but another form of allergy, such as house dust mites.

Hay fever is not a common disease

People without hay fever often can not imagine how stressful the symptoms of a pollen allergy actually are: The constantly itchy, watery eyes and the heavy sneezing attacks with runny nose severely limit the quality of life of those affected. In addition, hay fever often causes allergic asthma after a few years. Doctors also refer to this as a change of level, as the complaints from the upper respiratory tract spread deeper into the respiratory tract (lungs and bronchi).

Hay fever: symptoms

Everything important to the typical signs of hay fever read in the article hay fever symptoms.

Hay Fever: Causes and Risk Factors

Dysregulation of the immune system

As with all allergies, the allergic reaction to hay fever (pollen allergy) is caused by an overreaction of the immune system. The immune system is an extremely complicated system of different cells and proteins. Its task is to fight pathogens that have invaded the body. In hay fever, however, the harmless proteins of pollen are mistakenly classified as dangerous and fought like a pathogen.

The result is an inflammatory reaction, which is triggered among others by the inflammatory messengers histamine and leukotrienes. These inflammatory messengers are released by so-called mast cells when the pollen proteins are detected by defense cells. Since the pollen proteins enter the body mainly through the mucous membranes of the eyes, nose and throat, the local defense reaction of the body is revealed – the typical symptoms of hay fever such as sneezing and itching, runny or stuffy nose and watery tears develop Eyes. Frequently, people with hay fever also have allergies to certain foods. One speaks then of a cross allergy.

How does the dysregulation of the immune system develop?

The processes involved in pollen allergy have been well studied. What causes a hay fever but ultimately, there are only assumptions. Certain risk factors probably contribute to the development of hay fever with great certainty:

inheritance: Some people are more prone to allergic reactions than others. This is also called “atopy”. People with hay fever often suffer from neurodermatitis (atopic dermatitis), asthma or other allergies (animal hair allergies, insect sting allergies, etc.). The allergic reaction is inheritable. This does not mean that every child of allergic parents becomes an allergic person, but the risk is increased, as the following comparison shows:

• If no family member is allergic, children have an allergy risk of about 5 to 15 percent.
• If a parent or sibling is allergic, the risk is about 25 to 30 percent.
• If both parents are allergic, the child develops with a chance of about 40 to 60 percent also an allergy.
• If both parents have the same allergy, the child is at risk of allergies about 60 to 80 percent.

Hygiene Hypothesis: It may also play a role in the emergence of an allergy (hay fever, etc.), how much the immune system is required during childhood. The so-called hygiene hypothesis assumes that the immune system is under-challenged by very pronounced hygiene during childhood, and therefore at some point it also acts against harmless substances. For example, children who grow up with siblings or attend day nursery suffer less frequently from allergies, as observations show. Even children who grow up in a rural setting (for example on a farm) have a lower risk of allergies. The contact with many other people (other children) or with “dirt” (farm) could be a “training” for the immune system, while too strong hygiene defies the immune system and thus promotes the development of allergy.

Tobacco smoke: Substances in the ambient air, which irritate the respiratory tract, can contribute to the development of an allergy (hay fever, etc.) and asthma. For example, children who grow up with smoking parents have a much higher risk of developing asthma, hay fever or other allergies later on. But even smoking during pregnancy is dangerous for the child, as the ingredients of tobacco smoke can lead to numerous malformations and developmental disorders (for example, in the lungs). An expectant mother should therefore never smoke during pregnancy. Later, smoking should generally not take place in the presence of the child.

More and more people are suffering from hay fever

Around 20 percent of people in Germany are already struggling with hay fever (pollen allergy). Experts of allergological societies in Germany suspect that this number will increase even more: every second could be sensitized in 2050 at least against a type of pollen.

Researchers from the Center for Allergy and the Environment (ZAUM) of the Technical University in Munich see an important reason for the increasing frequency of hay fever in climate change: The rising temperatures worldwide significantly increase the pollen season of many plants. The higher carbon dioxide (CO₂) Content in the air also stimulates the plants to release more pollen than before. In addition, the warmer temperatures facilitate “alien” plants, such as ragweed (Ambrosia) from the USA, to spread in Germany: Ambrosia releases mid-August to mid-September highly allergenic pollen, the main cause of allergies in the US (such as hayfever) are.

Air pollution by particulate matter or ozone pollution also causes the pollen proteins to trigger even more violent reactions. Researchers at the Max Planck Institute for Chemistry in Mainz assume that, for example, birch pollen is released by a chemical reaction with ozone (O₃) are two to three times more aggressive.

Hay fever: examinations and diagnosis

The right contact person in case of suspicion Hay fever (pollinosis) is a Doctor with the additional name “allergology”. These are usually dermatologists, ear nose and throat (ENT) doctors, pulmonary specialists, internists or paediatricians who have completed additional training to become an allergist.

At the first visit, the doctor will first ask about the complaints and the previous medical history (anamnesis interview). Usually he can already estimate from the description of the complaints whether it is hay fever. Possible questions of the doctor could be for example:

• Are you already aware of other allergies?
• Do you have eczema or asthma?
• Do your parents or siblings have allergic diseases like asthma, hay fever or atopic dermatitis?
• When exactly do the complaints occur? (At which time of the day, in which months of the year?)
• Where do the complaints occur? (Outdoors or only in the house?)
• Where do you live? (For example, in the country or directly on a busy street?)
• Do you take medicine?

Which pollens cause hay fever?

Whether it is hay fever, can be determined relatively reliably by the anamnesis interview alone. On the other hand, finding the triggering allergen is sometimes very difficult and is like a detective work. The first step is a look at the pollen calendar. There, the times are listed, in which the different plants usually release their pollen: Who, for example, already in January typical hay fever symptoms has responded probably hypersensitive to the pollen of alder and / or hazel.

Further investigations

Various diagnostic tests are available to identify those pollen species or species of pollen that someone is allergic to. The tests include skin test, provocation test and possibly a blood test for antibodies against pollen proteins. Three days before a skin test and provocation test, you should stop taking any medication that suppresses allergic reactions (for example, cortisone or antihistamines). Otherwise the test result will be falsified.

Prick test: The doctor or a helper pricks in several places with a fine needle lightly into the skin and drips various allergenic solutions (such as with proteins of birch pollen, hazel pollen, etc.) on these small wounds. After a certain period of time, he examines the reaction of the skin and can see which allergens have caused an allergic reaction (such as redness of the skin).

Provocation test: The suspicious substance is applied under medical supervision in the nose, on the bronchial or conjunctival mucosa. If the reaction is positive, the mucous membranes swell up, causing discomfort. This test can lead to further, sometimes severe, allergic reactions (including anaphylactic shock), and the patient should be monitored for at least half an hour thereafter.

Blood test for antibodies: The “RAST” test can be used to investigate whether antibodies (specific immunoglobulins IgE) to pollen proteins are present in the blood. The more such antibodies to the pollen protein circulate in the blood, the stronger the allergic reaction.

Hay fever in children

Hay fever can also occur in babies and toddlers. Usually, they do without a skin test and provocation test, since both are unpleasant for the children and they usually defend themselves vehemently against it.

Hay fever in pregnancy

Even with hay fever during pregnancy should be waived due to the potential allergic overreaction (anaphylactic reaction) on a prick test and a provocation test.

Hay fever: treatment

How hay fever is treated, read in the article Hay Fever – Therapy.

Hay Fever: Prevent

The safest way to prevent hay fever symptoms is – in addition to the specific immunotherapy – the avoidance of pollen. This is not easy, because they can float for many miles through the air. However, the following tips can help:

Travel: Those who have the opportunity, should travel to the pollen season of “his” plants in areas where the plants in question are not or are no longer blooming. Or you drive in regions where these plants do not occur at all, such as in the high mountains at altitudes above 2000 meters, in coastal areas or on islands. There is generally low pollen poverty.

Air only at certain times: In the countryside, the pollen concentration is greatest between four and six o’clock in the morning, which is why people with hay fever should only air in the evening between 7 and 12 o’clock. Conversely, it is in the city: There is the lowest pollen concentration in the morning between six and eight o’clock, which is why in the city in the morning should be aired.

Pollen guards on Attach window: A pollen grid looks similar to an insect net. It not only keeps away flies and mosquitoes, but above all prevents the penetration of pollen into the living space. Especially for hay fever patients who like to sleep with the windows open, a pollen screen on the bedroom window is recommended.

Keep bedroom free of pollen: Anyone who puts off his street clothes in front of the bedroom and washes his hair before going to bed prevents pollen from spreading in the bedroom. Freshly laundered linen (such as sheets) should not dry out in the open air, as otherwise pollen may adhere to it.

Free living space from pollen: If you hang a wet towel in the apartment, the pollen will stick to it. In addition, you should vacuum in the pollen season as possible daily to remove the pollen on carpets and in the furniture. Hay fever patients should leave the sucking to someone else and not be present at the same time. Alternatively, you can get a special fine dust mask from the hardware store (so-called FFP3 fine dust mask). It keeps pollen effectively away from the respiratory tract and is especially recommended when dusting, because it causes the pollen to be whirled up.

Pay attention to pollen forecast: Meanwhile, there are numerous ways to find out about the current pollen count, similar to the weather. Radio, newspapers and especially the internet (pollen-app!) Offer a regular pollen forecast. On days with heavy pollen load, hay fever patients should avoid physically strenuous activities. Those affected may also need more medication if the pollen load is heavy.

Get a poll calendar: A pollen schedule (see above) provides hay fever patients with an approximate guide to when to expect complaints. This can be very useful, for example, for vacation planning. Pollen schedules are also available at almost all pharmacies for free.

Pollen protection while driving: In the car it means switching off ventilation and close windows. In many car models, the ventilation systems can be retrofitted with pollen filters. This is a worthwhile investment in case of severe hay fever, as uncontrollable sneezing attacks during driving seriously affect road safety.

Rain instead of sun: Rain reduces the pollen concentration in the air. People with hay fever should therefore rather use rain showers and the time shortly after for walks.

Hay fever: disease course and prognosis

In many cases, hay fever occurs relatively early, so in childhood or adolescence. But in the end it can appear for the first time in every phase of life. The pollen allergy usually persists for a lifetime and usually increases without treatment. Above all, the change of floors, so the expansion of the pollen allergy to the respiratory tract, here is a problem. With the right therapy but you can significantly mitigate the symptoms and complications hay fever prevent.