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Sneezing, runny nose, red eyes, itching… If for the first time in your life, you spent spring blowing your nose, repeating that you’re not sad and getting negative Covid-19 tests, there’s a very good chance that you’re now part of the allergy team. Because yes, there’s no age limit to join this not very popular club.
Indeed, contrary to what is sometimes believed, it is quite possible to see symptoms of respiratory allergies, but also food allergies, manifest late in life.
Understanding the mechanisms of allergy
«We must fight against the preconceived idea that allergies, which correspond to an inappropriate and exaggerated reaction of the body to substances present in the environment, only begin in childhood, explains Dr. Catherine Quéquet, allergist and author of New allergies – How to recognize them? How to fight them? (Rocher editions). You can become respiratory or food allergic in adulthood, around 40 years old and even around 60 or 70 years old, since allergies in the elderly are now an additional concern..»
To understand it, we need to explain a little about the allergic mechanisms. Respiratory allergies – caused by pollen, dust mites, mold or animals – and a large proportion of food allergies – for example to eggs, fish, peanuts or wheat – are dependent on antibodies. IgE. These are produced hereditarily by so-called “atopic” people, after contact with environmental proteins which do not trigger any reaction in non-allergic people.
“For all these allergies dependent on specific IgE, there is always a prior period of sensitization, during which the person produces IgE antibodies specific to the food or respiratory allergen without experiencing symptoms, explains Dr. Catherine Quéquet. This sensitization period can last several months or even several years, and it is as contact with the allergen progresses that the allergy can be triggered with the appearance of clinical symptoms. Thus, one may have the impression that it appears overnight, whereas there has been a period of sensitization for several years.
It should be noted that certain factors can aggravate allergic symptoms. This is particularly the case for indoor or outdoor air pollution, humidity, climate change for respiratory allergies, taking certain medications such as nonsteroidal anti-inflammatory drugs or beta-blockers, or alcohol.
Allergic one day, allergic (almost) always
Once the allergy is there, it is very rare for it to disappear on its own. Only certain food allergies present in children, such as those to milk and eggs, tend to dissipate with age. For the others, you should not expect a miraculous cure without any intervention (we will come to that).
“If you become, for example, allergic to birch or dust mites at the age of 30 and you do nothing, the allergy will remain”, warns Dr Sébastien Lefèvre, head of the allergology department at CHR Metz-Thionville and president of the National Professional Allergology Council (CNPA). The specialist points out, however, that there may be fluctuations in the intensity of symptoms depending in particular on weather conditions, indoor ventilation, humidity, etc.
So, if you are experiencing allergy symptoms, a consultation is necessary to determine precisely the cause of your ailments – for example, to specify whether your chronic rhinitis is caused by mold, dust mites or even your cat. «When a respiratory allergy is suspected, it sometimes takes several years for the person to really realize it.explains Dr. Catherine Quéquet. It is often the repetition of symptoms throughout life that will lead him to consult.»
Avoidance, symptom treatment and immunotherapy
After an initial assessment, the doctor will refer you to an allergist for skin prick tests and a blood test measuring specific IgE directed against this or that allergen. “This is an opportunity to differentiate between the sensitization stage and the allergy stage.”, notes the specialist. So, the treatment will be based on several axes: avoidance (at least as much as possible, because it is not always easy to make a respiratory allergen disappear), symptomatic treatment with antihistamines, corticosteroids in nasal spray, and sometimes eye drops.
“In the case of associated asthma, respiratory function tests are carried out in order to assess the need for background treatment and the prescription of treatment in the event of an attack”says Dr. Quéquet. It may then be decided to implement allergen immunotherapy – what was previously called “desensitization”. This treatment lasts between three and five years and is done sublingually, by drops or tablets. “It’s a treatment that works well, especially if started early.”comments Dr. Lefèvre. The fact remains that it is not always sustainable and that it will probably be necessary to start again about ten to fifteen years later.
“We always advise people with food allergies to favor homemade products, because processed industrial products modify the intestinal microbiota.”
Regarding food allergies, you should also consult. Usually this happens more quickly because the symptoms are louder and more alarming. “A precise assessment, with tests, a blood test and if necessary a provocation test in a hospital environment is essential”says Dr. Catherine Quéquet. Indeed, she points out that it is important to confirm the allergen that is in question, because specialists are seeing more and more patients with multiple food allergies with more severe reactions. However, knowing precisely what is causing the allergy allows for an effective avoidance strategy.
«People with food allergies are always advised to opt for home-made products, because processed industrial products modify the intestinal microbiota, thus promoting the appearance of new food allergies, points out the allergist. Food industry manufacturers must comply with the list of fourteen allergens that must be declared on packaging and on products sold in bulk. And restaurateurs and food industry professionals are required to provide consumers with information on the presence of the fourteen allergens that must be declared in the composition of their dishes. New allergens that are called “emerging”, such as goat’s milk, buckwheat or lentils, could one day be added to this list..»
In addition, the challenge test carried out in the hospital makes it possible to assess the quantity of food needed to trigger a reaction, so that oral immunotherapy can then be started. “Even if it is still a bit artisanal, the principle is to establish a protocol and gradually increase the doses in order to raise the tolerance threshold”reveals Dr Sébastien Lefèvre.
So, while we cannot hope to spontaneously recover from an allergy that appears in adulthood, it is nevertheless possible to control it. Spending spring with your nose in a handkerchief is not inevitable.
