What is hay fever?
Hay fever belongs to the most common form of allergy, the so-called immediate allergy: within minutes or even seconds, your body reacts with allergy symptoms when the mucous membranes of the nose, eyes or airways come into contact with pollen. The name hay fever can be traced back to the 19th century. At that time, the allergic reaction was first observed after contact with grasses and hay.
Hay fever: frequency and age
Depending on the source, up to 25 percent of Swiss men and women suffer from hay fever. In principle, anyone can fall ill with it. If the mother and father are already affected, the risk for their children rises to over 60 percent. If neither parents nor siblings are allergic, it drops to 15 percent.
The first symptoms usually appear at preschool age. In contrast to many diseases that medical progress has been able to contain or even conquer, hay fever and other allergies are on the rise worldwide. On the one hand, researchers blame negative environmental influences for this. On the other hand, the risk of allergies is increasing due to improved hygiene standards. The cleaner and more germ-free our environment is, the higher the risk of developing an allergy later on. Studies have shown that children who grow up on a farm are less likely to suffer from allergies than city children. Apparently, contact with certain bacteria and fungi strengthens our immune system. If, on the other hand, it feels underchallenged because it does not have to fight pathogens due to clinical cleanliness, it defends itself excessively against harmless substances, which then leads to pathogenic allergic reactions. Allergies are therefore not the result of a weakened immune system, but on the contrary a misdirected, excessive reaction of the immune system.
Hay fever: causes and risk factors
Hay fever develops because your body’s immune system reacts incorrectly to certain proteins in pollen that is actually harmless. After the first contact, your immune system produces certain antibodies, so-called IgE antibodies.
If pollen later hits the mucous membranes of the nose, eyes or airways again, the IgE antibodies bind to mast cells, which are also part of your body’s immune system.
The mast cells release inflammatory hormones: histamines. These messenger substances trigger the usual hay fever symptoms:
- Your nasal mucosa and conjunctiva become red and swollen.
- At the same time, the hormone constricts your bronchial tubes.
- In addition, the immune system’s defense cells cause inflammatory reactions in the affected areas.
The pollen of various wind-pollinated plants can trigger hay fever:
- Grasses including cereals (e.g. timothy, rye),
- Trees (including birch, alder, willow, ash, olive),
- Shrubs (including hazel) or
- Herbs (including mugwort, ragweed).
Hay fever sufferers always react to pollen from specific plants (e.g. hazelnut pollen). Many patients react to pollen from several plants at the same time: For example, they may be allergic to trees and grasses at the same time.
Hay fever is usually seasonal. This means that the allergy only becomes noticeable during the typical pollen seasons in spring, summer or fall. However, some plant species flower well into late fall or start flowering in late winter. This is why hay fever can occur almost all year round or several times a year.
Symptoms: Hay fever mainly affects the nose and eyes
The usual symptoms of hay fever (pollen allergy, pollinosis) mainly affect the eyes and nose. If the allergy triggers reach the nasal mucosa, allergic rhinitis (allergic rhinitis) develops; if they reach the eyes, conjunctivitis (inflammation of the conjunctiva) quickly develops. The most common symptoms are
- itchy, burning, reddened, watery eyes
- itchy, tingling, blocked nose
- Sneezing and sneezing fits
- Runny nose
- Dry nasal mucosa
Hay fever can also trigger many other symptoms:
- Your throat scratches and hurts.
- The mucous membranes in your mouth, throat and ear itch.
- You have a cough.
- You experience allergic skin reactions (e.g. redness, swelling).
- You have problems concentrating.
- You sleep badly.
- Their sense of smell, taste and hearing are impaired.
- You generally feel weak and tired.
Some people who suffer from hay fever react hypersensitively to non-specific stimuli such as tobacco smoke, dust, perfumes, temperature changes and physical stress – for example with sneezing or watery eyes.
Cross-allergy: food also triggers symptoms
Cross-allergies to certain foods often accompany the symptoms of hay fever. This is because the critical proteins in the pollen and certain proteins in food are structurally similar. Your immune system therefore reacts to the food protein in a similar way to pollen.
Eating the food in question then causes the following symptoms in the mouth and throat:
A cross-allergy can occur to various foods, depending on which plant pollen triggers your hay fever. For example, many people with a hazelnut, alder or birch pollen allergy also show symptoms to hazelnuts, apples or cherries. It is typical that each type of pollen is associated with certain foods.
| Pollen type |
Allergenic food |
| Birch, alder, hazel |
Apple, apricot, avocado, pear, hazelnut, carrot, potato, cherry, kiwi, almond, Brazil nut, plum, peach, celery, walnut |
| Mugwort |
Aniseed, dill, camomile, carrot, caraway, paprika, parsley, pepper, celery, mustard (black and white) |
| Grasses |
Peanut, potato, rye, soy, tomato, wheat |
| Ambrosia |
Banana, cucumber, honeydew melon, watermelon |
Diagnosis of hay fever
With an allergy test, we can detect hay fever and identify the trigger, i.e. the allergen.
The prick test
The prick test is the most common diagnostic tool. We drip various pollen extracts and other allergens (e.g. animal hair extracts) onto your back or forearm. We then prick the skin under the drop slightly using a fine needle. If you have an allergic reaction to one or more of the substances, the area of skin will redden, swell slightly and usually itch after 15 to 20 minutes.
The blood test
A blood test by us confirms the allergy diagnosis: if you suffer from hay fever, antibodies against the respective allergens can be detected in the blood using the enzyme allergy sorbent test (IgE-CAP test). In addition, highly differentiated detection options for individual allergy-triggering proteins are now available (molecular allergy diagnostics), which allow better statements to be made about cross-reactions, possible allergy risk or the expected response to hyposensitization/immunotherapy.
Provocation test
Sometimes we also use a provocation test with the relevant allergen. To do this, we spray pollen into your nose using an atomizer. This intervention can provoke a strong allergic reaction. Therefore, this test may only be carried out under medical supervision. We will then continue to monitor you for at least half an hour.
Who carries out the tests for hay fever?
Doctors in the allergy consultations at the hospital, specialists in dermatology, otorhinolaryngology or pulmonology carry out the diagnosis. Doctors with the additional qualification of allergology are specially qualified to treat allergies.
Hay fever: prevention, early detection, prognosis
Hay fever symptoms often appear as early as childhood. Even if you were not affected until adulthood, you can develop an allergy to pollen at any time in later life.
Preventing hay fever
There are mainly genetic causes if you develop hay fever. Certain behaviors can hardly prevent the disease. At best, the risk can be reduced. Parents in particular need to protect their children:
- If there is no medical necessity, do not give birth by caesarean section.
- Make sure that the climate in your home is right and that mold does not develop.
- Protect your child from cigarette smoke and, above all, do not smoke yourself.
- Protect it from air pollutants both indoors and outdoors.
The first measure for all allergies is to avoid the allergen causing the symptoms as far as possible. Experts speak of allergen avoidance or exposure prophylaxis. In the case of hay fever, this strategy is almost impossible, as the pollen is in the air we breathe and spreads for miles.
Hay fever: early detection
Hay fever is not a trivial illness. If it is not treated, half of those affected will experience worsening symptoms, including allergic asthma. The risk is particularly high for children. It is therefore important to recognize and treat allergic symptoms at an early stage. In addition, the pollen allergy can quickly spread to other substances: A cross-allergy then develops – to certain foods, for example.
Hay fever: prognosis
The right treatment can keep the acute symptoms of hay fever at bay and prevent them from getting worse. Hyposensitization can make patients insensitive to the allergy triggers. This minimizes your risk of developing further allergies. In some cases, people with the disease even become completely symptom-free. The chances of success are good, especially if treatment is started early.
Hay fever: therapy urgently needed
Many patients do not take hay fever seriously and therefore risk the so-called stage change. This means that the allergic reaction spreads to their lower airways, i.e. the bronchi, and causes allergic asthma there. Common asthmatic complaints are
- Cough
- Shortness of breath
- Whistling noises when breathing
- Tightness in the chest
Details of the treatments
