Immune system: if you know it, you manage allergies better

Never before has the immune system been the protagonist of our attention. Just look at the pharmacy setups to see how, alongside the “usual” antacids and anti-inflammatories, the new protagonists have become the supplements dedicated to the great manager of our defenses. Which has to do with viruses, but also with pollen. In fact, the long phase of seasonal allergies has begun, and understanding why sneezing, conjunctivitis and shortness of breath can suddenly explode is strategic for knowing what to do.

To this end, we benefit from the advice of two special experts.
265568The first is Philipp Dettmerfounder of Kurzgesagt (which translated means “in a few words”), the most followed YouTube science channel in the world and author of Immune. Journey into the mysterious system that keeps us alive
(Rizzoli, € 27, photo on the right). And then a specialist in allergy and hospital clinical immunology, Mona Rita Yacoubcoordinator of the allergological area of ​​the IRCCS San Raffaele Hospital of the San Donato Group.

How the immune system reacts

Dettemer writes in his Immune: “The balance of the immune system is very precarious. If it doesn’t react with enough force, even the smallest infections could quickly turn into deadly diseases and kill you. But if he reacts too violentlyAt that time can do more damage than any other infection: the immune system is far more dangerous to our survival than the worst pathogen. Think of Ebola, a rather disgusting and horrible disease that takes roughly six days to kill while the immune system may only need a scant fifteen minutes. People with allergies experience this dark side of their defense network firsthand. When the immune system loses control, it becomes lethal and kills thousands of people from anaphylactic shock every day. ”

But why does the immune system do such a thing? Mona Rita Yacoub explains it to us: «The allergic patient is a person genetically predisposed to react abnormally to substances that are harmless to most of the others, allergens. Thus some of us become sensitized, that is, they produce antibodies against these “enemies”. This genetic predisposition to produce antibodies belonging to the IgE class against agents commonly present in the environment, such as dust mites or pollen, it’s called atopy. It is also very common for an allergic person to have relatives in the family who have the same problem: those who have one or more allergic parents are likely to become allergic toobut we have patients who develop an allergy without familiarity.

THE environmental factors they are in fact very important and explain why even those unfamiliar with allergic diseases can develop it, even in old age. It is therefore born with a predisposition and then factors intervene that make it express itself or not. The main suspects are pollution, but also viral infections and the concentration of exposure to allergens ».

It’s never too late

“Atopy is expressed already in the first years of life: the typical allergic patient has atopic dermatitis, allergy to milk or eggs or asthma in the first years of life, and then as a teenager he will have rhinitis»Explains the allergist. “But you become allergic at any age: a person can develop rhinitis at the age of 60 because for example he has moved to an area where there is ragweed, a very strong allergen to which one becomes sensitized even with a “new” exposure ».

How do you become “sensitive”

Dettmer writes: “The source of the immediate hypersensitive reaction is in the blood. This is where the most troublesome part of the immune system works: the immunoglobulin E, or IgE antibodies. You can say thank you to IgE for much of the suffering related to allergy. What they actually do. IgE antibodies when an allergic reaction occurs? Hypersensitivity always occurs in two stages: first you must meet your new mortal enemy. And then you have to meet him again. “Yacoub comments:” If you expose yourself to a high dose of allergens you are more likely to become allergic, but if this exposure is constant but in low doses, you can develop a tolerance to those same substances. This happens for example to those who have a pet: with our cohabitation immune system can learn to live with with the possible allergen which therefore works a bit like a desensitizing therapy or vaccine. The difference is made by the constant exposure and the low dose of allergen with which we come into contact. With pollen, on the other hand, in addition to the high dose of allergen, there is also the factor of intermittent exposure: they come and go in periods, and this intermittence does not favor the process of tolerance, but that of sensitization ».

The most dangerous foods of pollen

Dettmer: “Immediately after the first bite something unusual happened, you felt strange, tense. You are hot and you start to sweat, your ears, face and hands are swollen, suddenly you realize that you are struggling to breathe and you go a a little panic. As you get up, your friends ask if everything is okay, but you have to sit down immediately because your head is spinning. ” Yacoub: “With food an exponential reaction can occur in those who are allergic: in the case of patients sensitized to some allergenic molecules, the reactions can occur with exponential severity every time that food is consumed, and therefore the symptoms can go from the oral syndrome allergic (itchy mouth) to urticaria / angioedema with only skin symptoms, up to anaphylaxis, severe systemic reaction involving multiple organs and possible hypotension or edema of the glottis.

There are also cross reactions between pollen and food, which are very frequent. However, these mainly give mild symptoms: for example, the person is allergic to grasses and therefore when he eats raw tomatoes (which contains molecules in common with pollen) he has itching in the oral cavity. These allergenic molecules, however, are denatured with heat and therefore the food is tolerated if cooked. To understand if we are faced with patients at risk of presenting serious reactions are available specific blood tests that analyze the allergenic molecules involved ».

“Light” cortisone and biological drugs

Not treating allergies well is very dangerous, Dettmer warns in Immune: “Since there are so many mast cells in the lungs, the allergic reactions that take place within them can become dangerous very quickly. In the worst case, anaphylactic shock can occur, which can kill a person in a matter of minutes. Allergic reactions are not a joke at all “.” Fortunately, the treatments and guidelines on drugs and allergen-specific immunotherapy (the so-called vaccines) are well established “, comments the allergist.” Specific immunotherapy, which consists in administering specific allergenic extracts at well-determined doses of the allergen for 3-5 years, is made to people with respiratory allergies, that is, with rhinitis and well-controlled asthma (if the asthma is severe, specific immunotherapy cannot be used). for patients allergic to dust mites but also to pollen.

The best candidates are those who usually need to use a lot of drugs constantly and for entire seasons to control symptoms: in these cases, specific immunotherapy is the optimal solution and leads to a great reduction in symptoms and drug consumption. The famous cortisone, on the other hand, used topically for asthma and rhinitis, is also safe in the child’s growth phase and prevents exacerbations, which are then those that require the use of therapies with systemic corticosteroids and sometimes even the access to the emergency room and hospitalization. Corticosteroids in tablets or for injections should be used as little as possible because they have long-term side effects: patients with severe asthma who have undergone several courses of cortisone during their life may already have osteoporosis or other at the age of 40-50. complications. Therefore, if cortisone is necessary for the treatment of exacerbations, as occurs in the cases of patients with severe asthma, we must evaluate whether it is possible to resort to biological drugs, which prevent inflammation through various mechanisms of blocking the cytokines mediating inflammation or of the same IgE “.

The role of stress

What is the effect of stress on the immune system? Dettmer explains: “One of the adaptations to stress is to speed up certain immune mechanisms and at the same time slow down others …”. Generally speaking, it appears that it is chronic stress obstacles the body’s ability to quench inflammation and cause chronic inflammation. And as we saw earlier, chronic inflammation is linked to an increased risk of contracting numerous diseases, from cancer to diabetes, heart disease and autoimmune diseases, as well as general frailty and a higher chance of death.

Stress also releases hormones such as cortisol which deactivate and weaken the immune system, making it less effective at doing its job. Wounds heal slower, infections are more likely to break out and cause disease. Chronic stress means a chronic release of cortisol. A rather strong connection has also been made in recent years between the onset of autoimmune diseases and stress. And stress also appears to be one of many risk factors for cancer progression.

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