1. It seems like more and more people have hay fever, is that right?
Thomas Rustemeyer is a dermatologist at Amsterdam UMC: “Yes, that’s right. Every year more people develop hay fever complaints. This is due to epigenetic changes. These are changes in the way our body uses genetic information, without changing the DNA.
“For example, your lifestyle, whether you sleep a lot or little, drink alcohol or smoke, your stress level and whether or not you exercise influence how your body functions. But above all, the world around you determines the accessibility and influence of allergens. A changing climate and environment, for example, and the extent to which you are exposed to pfas and particulate matter play a role in allergy development. These epigenetic changes are responsible for an annual increase in hay fever of 10 to 15 percent.”
Maurits van Maaren, internist, allergist and clinical immunologist at Erasmus MC: “Environmental influences, such as what you eat, how many antibiotic treatments you receive, whether you live in an environment with a lot of air pollution, whether you use a lot of soap or disinfectants and whether you grow up in the city or in an environment with cows and pigs also influence the chance that you will develop an allergy such as hay fever.”
2. Is hay fever hereditary?
Rustemeyer: “Yes, certainly. Hay fever, like allergic asthma and eczema, is an atopic condition. Atopic people often suffer from multiple types of allergies at the same time: this is called the atopic syndrome. If one of your parents has one of these conditions, there is a 40 to 50 percent chance that you also have it. If both parents suffer from atopic syndrome, there is a 70 percent chance that you are also affected. If neither parent has an allergy, the chance that you do have it is still 20 percent.”
Van Maaren: “Hereditary predisposition certainly plays a role. But one person is more predisposed to developing allergic conditions, such as eczema, hay fever or asthma, than another.”
3. Why does one person get severe hay fever and the other has no problems at all?
Rustemeyer: “Hay fever is an overreaction of the immune system, which reacts to substances that do not belong in the body. With every substance that enters the body, the immune system must choose: friend or enemy, allow or block? Important, because harmful micro-organisms must be recognized quickly.
“That selection is not always done accurately. Tree pollen can be seen as foreign to the body and can therefore be avoided. While these are not harmful substances in themselves. We call those allergens. A reaction of the immune system to an allergen is an allergic reaction. Allergens are usually proteins in pollen, dust mites, pet dander and foods.
‘Having hay fever has an advantage: it is a sign that your immune system is working well and active’
“One person does this differently than another, because one person’s immune system is more finely tuned than that of another. So immune development differs per person and per age. What is certain is that the younger you are, the more active your immune system is. That is why most allergies are developed in childhood.
“Having hay fever does have an advantage: it is a sign that your immune system is working well and active. This is important in countries where many parasites live, which can be life-threatening.”
4. Sometimes hay fever only develops later in life, why is that?
Rustemeyer: “Although hay fever most often develops in children aged 6 to 8 years, hay fever can in principle develop at any age and is therefore also very common among adults. Often the development of eczema in small children is the first clinical risk factor for developing an allergy. Eczema disrupts the skin barrier and is most likely necessary for the development of first a food allergy and later possibly hay fever and asthma.
“That is why pediatricians and clinics consider it so important that eczema is controlled at an early stage. Because once you have developed an allergy, there is a good chance that another allergy will develop. This can also happen later in life. Anyone who has an allergy is therefore extra vulnerable.”
5. Can hay fever be prevented?
Van Maaren: “You cannot prevent it completely. Of course you can’t do anything about the genetic predisposition, you inherit it from your parents. But you can minimize the predisposition to it by starting to optimize the living environment as early as possible. Children no longer play in the mud, spend a lot of time indoors behind a laptop or phone, wear clean clothes every day, and wash their hands often. The immune system then becomes bored and is more likely to respond to pollen, dust mites and foods.
‘Let children play outside and do a lot of sports, let them come into contact with livestock and agricultural land, because farm air has been proven to be healthy’
“So: let children play outside and do a lot of sports, let them come into contact with livestock and agricultural land, because farm air has been proven to be healthy. Take them to a fast food restaurant as little as possible, but let them eat a lot of yogurt and fish and give them as little antibiotics as possible if it is not really necessary. Reduce contact with disinfectants, because we have become way too clean. Frequent hand washing helped prevent the spread of corona, but is not good for developing allergies.
“To prevent an allergy, it is also necessary that a child from the age of 11 months is exposed to substances that can cause allergies, such as pollen and house dust mites. In addition, it is a good idea to give the child three times a week for a period of five years the foods that most often cause food allergies: peanuts, tree nuts, milk and chicken eggs. This is especially recommended for children with a brother or sister or with parents who have a food allergy.
“Once you are allergic, there are no treatments that can cure you of these conditions, but fortunately there are many and increasingly new and better treatments.”
6. Can hay fever be cured?
Rustemeyer: “That is difficult. But I dare say: no one has to suffer from hay fever. There are good hay fever remedies available, such as pills, eye drops and nasal sprays, all of which are safe and combat the symptoms.
“Immunotherapy is also an option for those who have very serious complaints. Injections are administered every four weeks for three years with small concentrations of allergens, such as grass pollen extract. In addition to injections, you can also opt for a melting tablet under the tongue every day. Goal: to become insensitive to the substance to which you are allergic.
“With the pills you immediately use the maintenance amount. With the injections, the amount is increased slightly with each step. Both treatments work in such a way that your body can gradually get used to it and your immune system responds less and less and ultimately no longer to the allergens and the hay fever symptoms decrease.”
Van Maaren: “In general, people are less likely to suffer from pollen or house dust mite allergies above the age of 50, but this does not apply to everyone. Injections or tablets are similarly effective. The advantage of allergen-specific immunotherapy over medication is that the effect is permanent after the end of three years of treatment. This is in contrast to medication, which only works if you continue to take it daily. Because it is an intensive and expensive treatment, it is intended for people who still suffer from pollen or house dust mite allergies despite medication
“Furthermore, staying on the coast helps to reduce exposure to pollen. Provided of course the wind comes from the west, otherwise the pollen will still blow into your nose from the interior.”
