Elena Meli
To identify allergies today, molecular tests guarantee broad-spectrum investigations and more effective diagnoses. Now the immune system can be gradually “educated” not to react to pollen
Every year the sneezing season starts a little earlier: climate change is bringing forward and even lengthening the difficult months for allergy sufferers. With temperatures constantly rising, flowers bloom earlier, the greenhouse effect increases the production of pollen and so over the last thirty years it has been estimated that the allergy season has extended by an average of about twenty days. Twenty more days of runny nose and sneezing for
a continuously growing group of people: in Europe the prevalence of
allergic rhinitis is around 23 percent, in Italy the estimates are between
16 and 25 percent but as Giorgio Walter Canonica of the Society explains
Italian Institute of Allergology, Asthma and Clinical Immunology (SIAAIC) «according to the
projections, between 35 and 40 percent of the Italian population will suffer from
allergic rhinitis by 2030″.
The appeal of scientists
Also for this reason a group of scientists at the beginning of April
from all over the world signed an appeal, published in Frontiers in Science, for the mitigation of the impact of climate change on diseases with an immune component: «Global warming is changing the exposome, i.e. the set of environmental factors to which we are exposed. The greater incidence of extreme climatic events puts the immune system under stress, pollution and the increase in pollen increase the probability that the defensive barrier of the skin and mucous membranes will be altered, the loss of biodiversity and the reduced exposure to germs due to current lifestyle are altering the balance of the immune system: the result is a greater risk of allergies, autoimmune diseases, tumors”, write the experts.
Mitigate pollution
The way out, in the face of a climate gone mad and human health at risk, should be a “global effort topollution mitigation and adaptation to the new conditions of the planet”, as the representatives of the main world allergy scientific societies write in the recent document. It is certainly not a trivial task and as Canonica explained during a meeting dedicated to respiratory allergies of Assosalute, the National Association of self-medication drugs part of Federchimica, «We must face spring with fingers crossed: if the trend continues, also thanks to the levels of air pollution, it will be a season with a big impact on those who are allergic.”
A perennial season
A season that for many is becoming perennial or almost: with the lengthening of the pollination months due to the average higher temperatures, those who are allergic to parietaria for example today have to deal with symptoms from February to November. The increase in pollen due to climate change, however, is only part of the problem, because many factors contribute to the greater discomfort of allergy sufferers and the increase in the number of patients, as Canonica specifies: «Allergies are not inherited, a predisposition to develop them. The problem is that the world we live in seems designed to make us allergic: today we know that the first step towards an allergy is the alteration of the barriers that protect us from contact with the outside, in fact the skin and the epithelium (lining tissue, ed.) of the gastrointestinal tract. Pollutants of all kinds to which we are exposed, from atmospheric smog to microplastics, also damage epithelia and mucous membranes and favor the entry of allergens into the body, facilitating the development of allergic sensitization. Among other things, the more pollution increases, the more damage to the mucous membranes becomes, which further contributes to strengthening the abnormal immune response that leads to allergy symptoms.
The role of food
«It’s not enough: even an incorrect diet (for example the “Western” diet, which is increasingly widespread and deviates from the Mediterranean diet by making extensive use of processed industrial foods, ed.), altering the composition of the intestinal bacterial flora, modifies the mucous membranes of the digestive tract, also favoring in this case the passage of allergens and the appearance of an anomalous immunological response. It can even happen in elderly people: the onset of allergic rhinitis can even occur at the age of 70 and it is good to be aware of this so as not to underestimate the symptoms and arrive at a correct diagnosis. The environment around us has changed a lot and now any time is a good time to become allergic”, continues Canonica. «Since the end of the pandemic there has been an explosion of respiratory allergies, especially among young people and children but also in adults: for a long time the mask had a protective effect from the inhalation of pollen, allergens, viruses and pollutants.”
A Trojan horse
As if that weren’t enough, it seems that pollen can trigger symptoms even in those who are not allergic, by attaching themselves to pollution particles: this was demonstrated some time ago by research from the Max Planck Institute in Mainz, Germany, observing that pollen can cause from vehicle for ozone, nitrogen dioxide and particulate matter which are thus transported and released deep into the airways. «The pollen from polluted areas are covered in harmful substances that alter their allergenic content and can strengthen their effect, causing allergic reactions more easily in anyone», comments Mario Di Gioacchino, Siaaic president. «Nitrogen oxides and ozone, in high concentrations, alter the protein components of pollen grains to the point of triggering rhinitis and cough even in those who are not allergic: some pollens, for example those of grasses, trigger the hyperactivation of cellular receptors that trigger the immune system’s reaction, regardless of whether you are allergic.” In short, the panorama is gloomy, considering that not much can be done to prevent allergies other than trying to have a healthy lifestyle, spending as much time as possible where the air is clean and perhaps taking out the mask again when we are forced to stay for a long time where the pollution is almost “tangible”.
The bulletins
Who already is allergic person can take specific precautions, for example by consulting the updated pollen bulletins: the service is offered by many Regions, otherwise you can consult the website www.pollinieallergia.net of the atmospheric monitoring network of the Association of Italian Territorial and Hospital Allergists and Immunologists. Also pay attention to the weather, because when there are thunderstorms or downpours with lightning the pollen can break and enter deeper into the airways, giving more intense symptoms.
Molecular analyses
The first rule, however, is to treat yourself well after receiving a correct diagnosis. «Many still underestimate the symptoms and the importance of an in-depth evaluation, which is no longer that of simple allergy tests on the skin», underlines Canonica. «Today, with a blood sample and extended molecular tests, you can analyze just under 300 antigens and discover cross-allergies (when the allergy to a pollen is associated for example with a food allergy because pollen and food share similar molecules, ed.), thus giving more precise indications for protecting oneself from the appearance of symptoms, but above all having the possibility of designing an immunotherapy specific for the antigen that causes discomfort more than all the others.
How immunotherapy works
Today immunotherapy for pollen allergies (which consists of slowly “re-accustoming” the immune system to tolerating them by exposing itself to gradually increasing doses, ed.) is simple, it is done sublingually and has accessible costs, which in some regions are reimbursed in whole or in part; above all, it can change the course of the disease because it has long-term effects, allowing tolerance to be maintained even for up to five or eight years after discontinuing the treatment. This radically changes patients’ quality of life and decreases the use of other drugs. Specific immunotherapy would be indicated for all pollen allergy sufferers in the absence of severe asthma, which must first be kept under control with biological drugs before immunotherapy can then be started; However, it is estimated that around one allergy sufferer in ten follows it, especially because many do not know it or think that it is still a matter of getting an injection a week.” The majority therefore manage the allergy with antihistamines, sometimes with nasal decongestants which, however, as Canonica underlines, «in the long run can cause problems. Allergies have an inflammatory basis, which is why the most valid therapy, especially in moderate and severe cases of allergic rhinitis, is the combination of steroids and inhaled antihistamines, which is also effective on conjunctivitis. Self-medication drugs can be helpful, but their use must always be managed with the help of the doctor”, concludes the expert.
April 20, 2024
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