Pollen allergy and climate change in childhood: causes, risks and home care

It's World Allergy Week, and the organization responsible for the event (the World Allergy Organization) aims to draw attention to the effects of climate change on the evolution of pollen allergies. Seasonal allergies occur throughout the year, But Spring doesn't only bring joy, but also “alters” bodily responses in many girls and boys with a predisposition to allergies.

Itching, congestion, rhinitis, eye irritation, sneezing, dry cough, feeling tired…; allergies are not only suffered during childhood, but data from an international study called ISAAC indicate that the prevalence in the 13/14 year old population is 22,1 percent. And the worst news is that climate change is increasing cases in very young children.because at just 3 years old they show signs and test positive in antigen tests, something that was much less common a few decades ago.

The critical period for people who suffer from pollen allergies These are the months of February to June, and it also coincides with the increase in visits to the pediatric emergency service. In spring, the plants that most induce allergies pollinate.But the warming of the Earth's surface brings many effects, including a greater density of plant species that produce pollen, longer pollination seasons, and more intense concentration peaks.

SEICAP mentions a review of studies published in Multidisciplinary Respiratory Medicine, according to which some factors such as vehicle emissions and a lifestyle “Westernized” These factors are linked to a higher frequency of respiratory allergies. This combination of pollution, climate change, and urban habits makes pollen not only more abundant but also potentially more allergenic.

What is allergy and why does climate change make it worse?

Climate change not only affects the number of people affected by allergies, but rather they bring forward and lengthen the symptom seasonIn many areas, it has been observed that children are starting to experience sneezing, itchy eyes, or difficulty breathing earlier than they did a few years ago, and these symptoms persist for longer. This means they are spending about two extra weeks (or even more) worrying about their allergies, as the earlier onset of symptoms is not linked to an early end to allergy season for each individual.

"We are seeing a longer season mainly due to warmer temperatures," he said. Mario Sánchez-Borges, MD, President of the World Allergy Organization.

Environmental allergy (in this case we speak of pollen as an allergen) considerably reduces quality of lifeaffecting the lives of allergy sufferers; and it's not just about physical signs, but also a decrease in energy levels, sleep disturbances, and emotional manifestations such as anxiety or irritabilitySpecialists offer the possibility of identifying and confirming allergies "in time" and advising on treatments and control measures to reduce symptoms.

The most recent research indicates that climate change It acts on respiratory allergies. through several interconnected paths:

• Increase in average temperaturewhich brings forward the flowering of many trees and prolongs the growing period of herbs and grasses.
• Higher concentration of CO₂ in the atmospherewhich stimulates plant growth and can increase the amount of pollen produced by each plant.
• Extreme weather events (heat waves, storms, torrential rains) that alter the biological cycles of plants and the way in which pollen is released and transported.
• Urban pollution, which modifies the proteins in pollen and can make them more irritating to a child's respiratory system.

Analyzing long series of pollen data in Europe, it has been observed that The pollen season is gradually lengthening. And the total annual burden is also increasing in many regions. For children with allergic rhinitis or asthma, this translates into more days with symptoms, more medication use, and more doctor visits, especially in low-income families.

Characteristics of the allergy

Allergy means a exaggerated and “strange” reaction of the immune system in response to external substances that are, in principle, harmless to most people. There is a clear difference between those who have allergies and those who don't: the latter's bodies are able to recognize these particles and neutralize them without causing inflammation.

Substances that cause symptoms upon contact with the body can be introduced orally. respiratory (pollen, mites), cutaneous (contact with certain metals or plants), digestive (food) or intradermal (insect bites). In the case of pollen, the grains are deposited on the mucous membranes of the nose, eyes, and bronchi, triggering an allergic reaction.

An allergen is capable of triggering allergic responses: they can be environmental (pollen, mites, fungi), foods (cow's milk protein, egg, nuts), drugs or chemical substances present in the environment. A person is not born with an already developed allergy.but awareness can be acquired over time; those responsible are, in general, the genetic load and the environment in which he/she lives.

In Europe it is estimated that up to 40% of the population may present pollen sensitivityHowever, not everyone who is sensitized develops severe symptoms. The risk and severity depend on factors such as:

• Duration of the exhibitionrelated to how long the pollen season lasts and the amount of time the child spends outdoors.
• Intensity of exposure, that is, the concentration of pollen grains per cubic meter of air.
• Pollen allergenicity, which is the ability of each type of pollen to trigger an intense immune reaction.

In Europe, the grasses (Poaceae family) are the main cause of pollen allergies due to their wide distribution. Among trees, the following stand out as highly allergenic: birch in northern and central Europe, and the olive tree and cypress in the Mediterranean region. In addition, some herbaceous plants such as the Ragweed (Ambrosia artemisiifolia) require special attention because they are invasive and extremely allergy-inducing in many areas.

How climate change affects pollen seasons

Pollen allergy is usually highly seasonalIn most European countries, the main pollen season spans approximately six months, from spring to autumn, although there are geographical differences depending on the climate and vegetation of each area.

Climate change problematic modifies these seasons in different ways:

• Preview of the start of the pollination season for many trees and grasses, due to milder winters.
• Longer duration global pollen season, so symptoms appear earlier and disappear later.
• Increase in total concentration of pollen in the air, which increases the likelihood of children developing allergies and the intensity of symptoms in those who are already sensitized.

Studies with data from multiple countries have shown that the pollen season It lengthens on average by almost one day per yearand that the global pollen load has been increasing in recent decades. Some climate projection scenarios estimate that the length of the pollen season could increase by around 20%, and the total annual concentration by more than 15-40%, posing a significant challenge to children's health.

In addition, the Cities act as “heat islands”Higher temperatures and urban pollution further advance flowering and can intensify pollen release. Children living in urban areas, especially in neighborhoods near major avenues, may face a double burden: More pollen and more pollutants that irritate the respiratory mucosa.

Humidity, solar radiation, and rainfall also play a role. For example, the abundant rains in the preceding months They promote plant growth and can increase available pollen, while some storms during pollen season can fragment the grains into very small particles that penetrate deeper into the airways and trigger asthma attacks.

Children with pollen allergies: symptoms, risks and care

In young children, pollen allergy often manifests as allergic rhinitis (famous “hay fever”) and conjunctivitisThe most common symptoms are:

• frequent sneezing in series, especially outdoors or upon waking.
• Nasal congestion and runny nose, with a constant need to blow their nose.
• Itching of the nose, eyes, palate, or throatwhich can lead the child to rub their face a lot.
• Red eyes, watering and a gritty feeling.
• Dry cough or wheezing in children with allergic asthma.
• Tiredness, irritability y sleeping problems due to nighttime congestion.

If not properly controlled, allergic rhinitis can lead to loss of concentration at schoolThis leads to decreased performance, increased absenteeism, and a significant impact on the emotional well-being of the child and family. Several studies indicate that a large proportion of allergy patients are not properly diagnosed or treated, despite the availability of effective and relatively inexpensive treatments.

In this context, climate change exacerbates the situation because:

• The number of days per year with pollen in the air is increasing., complicating allergen avoidance.
• It favors the spread of highly allergenic invasive species, like ambrosia, towards new geographical areas.
• Increase combined exposure to pollen and pollutants (NO₂ozone, fine particles), which can increase inflammation of the respiratory mucosa.
• It increases the likelihood of respiratory infections by weakening the defensive response against viruses, as some recent studies have shown.

Do you have a daughter or son with a pollen allergy?

From the Respiratory Allergy Working Group of the SEICAPTherefore, we offer this ten-point guide, which we transcribe below, and we hope it will be useful. These recommendations become even more important in the context of climate change, where pollen seasons are longer and more intense:

1. It is not advisable to go to the countryside, parks, gardens or places with abundant vegetation, between the months of March to MayAreas with grass should be avoided, especially if it is freshly cut, because handling the grass releases even more pollen grains into the air.
2. It is recommended to protect windows or balconies, especially the child's bedroom, with a very dense mesh of plastic material (mosquito net), which should be cleaned daily with a damp cloth, without shaking, so as not to redistribute the accumulated pollen.
3. Keep the windows or balconies of the child's bedroom closed as long as possible, especially at night, when the concentration of atmospheric pollen increasesand in the early hours of the morning, which is when many plants release the most pollen.
4. Two hours before going to bed, with the windows closed, spray water towards the ceiling and then keep the room closed until going to bed. This allows the pollen floating in the air to settle, reducing the amount available to inhale.
5. Abroad, Protect your eyes with sunglasses in case of seasonal conjunctivitisand use approved anti-pollen masks on days of high concentration or in risky activities (parks, countryside, outdoor sports).
6. If traveling by car, keep the windows closed and use the air recirculation system when pollen concentrations are very high. Check that the pollen filters the vehicle parts are in good condition and replace them according to the manufacturer's instructions.
7. Remove items that can accumulate dust or pollen (excessive stuffed animals, carpets, heavy curtains, or others). Do the house cleaning without shakingUsing a vacuum cleaner with a suitable filter or a damp cloth; avoid sweeping dry, as it raises the particles.
8. Consult (press, television, mobile applications, internet) the pollination dataTake precautions when there are more than 50 pollen grains per cubic millimeter of air, as this amount can trigger symptoms in most allergy sufferers. There are apps and specialized services that provide alerts about the concentrations of the most common pollens in each area.
9. It is advisable that the child always carry in his backpack, during the time of greatest risk, Bronchodilators or antihistamines prescribed for allergy symptomsalways following the guidelines indicated by your pediatrician or allergist.
10. Consult a pediatric allergist if symptoms persist or if asthma is suspected, so they can make a correct diagnosis and assess the need for personalized treatment. immunotherapy or other medium and long-term strategies.

In addition to this ten-point plan, other specialists recommend some additional measures in periods of high pollen concentration:

• Shower and change clothes Upon arriving home, to remove any remaining pollen from the skin and hair.
• Do not hang clothes outdoors during pollen season, as textile fibers easily trap the grains.
• avoid doing intense outdoor exercise during peak pollen hours, especially for asthmatic children.
• Discuss with a healthcare professional the early initiation of preventive medication (for example, antihistamines or nasal corticosteroids) a few weeks before the peak season begins.

If you would like to get more information about the event, you can check here, in this other place, or follow the hashtag #WorldAllergy Weekwhere resources, infographics and updated advice on allergies and climate change are shared.

Image - (Last) Sara goldsmith.

The scientific evidence accumulated in recent decades confirms that Climate change is worsening respiratory allergies and increasing the burden they place on families. A better understanding of how temperature and CO2 influence these factors is needed.₂Pollution and extreme phenomena in the production and allergenicity of pollen, as well as applying simple prevention measures and going to the pediatric allergist when necessary, allow girls and boys with pollen allergies to continue living as full a life as possible despite an increasingly changing environment.