An allergy is an exaggerated response of the immune system to a substance that should be harmless. Our Immunity is designed to tolerate substances that are innocuous, such as dust, pollen or peanuts. However, sometimes it overreacts and causes severe reactions to these substances.

Allergies are usually not curable, so treatment is directed towards reducing symptoms and improving quality of life. In a way, treating an allergy is as much about controlling the disease, as it is about learning how best to live with it. Allergies can cause severe attacks or even be fatal. However, most allergies are not dangerous, as long as there is a well-structured medical plan.

There are many types of allergies. Some occur more frequently, like respiratory, food or drug allergies. Others are fortunately rarer, like to physical exercise, insect stings or human sperm.

Allergies can arise at any stage of life. So, unfortunately, even patients that have never developed one, can suddenly find themselves with bothersome symptoms. Still, most cases appear at an early age, between three and twelve years.

How to prevent an allergy?

An allergy is caused by complex interactions between our body and the environment, which makes prevention difficult. There is no one specific reason for developing an allergy, because "they arise from an interaction between our genetics and the environment to which we’re exposed. It’s what we call a multifactorial disease", explained Dr Pedro Morais Silva, Allergy and Clinical Immunology specialist at the HPA Health Group and Professor of Medicine at the Algarve University.

“Some of the biggest risk factors are genetic and unavoidable, like having an allergic mother or father. But that’s just one possible variable” he said.

“The type of environment a person is exposed to, the type of food the mother ate during pregnancy or during breastfeeding” are also likely risk factors. But exactly what foods to eat in those circumstances is still open to debate and currently, there is little to recommend beyond eating healthy and living in a pollution-free environment. Other risk factor, however, are more easily avoided. Primarily, avoiding contact with tobacco smoke. “Children who have contact with tobacco smoke are more likely to develop respiratory allergies than children who don’t”, continued Dr Pedro Silva, explaining that the same applies to pollution. "Also, feeding exclusively with breast milk for at least four months seems to prevent respiratory and food allergies," he said.

In relation to protecting a child from an allergy by avoiding contact with an allergen or, on the contrary, promoting this contact to create resistance, Dr Pedro refers that contact with allergens as a preventive factor is ambiguous and further evidence is needed. “Early (i.e. in the first 2 years of life) contact with food allergens, like milk, eggs, fish and peanuts, after a 4 to 6 month breastfeeding period seems to be protective. We recommend early introduction of allergenic foods, as it likely decreases food allergies. However, as far as respiratory allergies are concerned, the situation is not as clear and there are contradictory studies. You don’t currently recommend allergen avoidance without evidence of an established allergy”, he told The Portugal News. “The problem is that we cannot predict which people are genetically predisposed to having an allergy. In other words, if your child has a high probability of having allergies, then contact with mites or dust is probably not so good, but if your child does not have this genetic predisposition, contact with dust may actually help the immune system to develop properly”.

Getting an appointment

The Immunoallergology consultation at HPA Health Group follows established European best practice guidelines.

“In short, when a person has allergy complaints, the first thing we do is to look at the medical history, talk lengthily to the patient, understand when the symptoms first began, their intensity, etc. After that, various procedures are carried out to identify exactly what the person is allergic to, either through skin tests, blood tests or other specific tests”, Dr Pedro pointed out.

“We try to reach to a diagnosis and treatment plan as quickly as possible. During the first appointment, ideally all patients leave, knowing what they are allergic to and with a well-structured treatment plan”, said Dr Pedro.

“Our goal is always to reduce symptoms over time, improve the global quality of life and, if possible, to desensitize the patient so that future allergy manifestations are milder”, he told The Portugal News.

According to Dr Pedro, allergies, even severe ones, are manageable, as long as there is a medical plan. “We try to empower patients to correctly identify, prevent and treat allergy symptoms. There is a big emphasis on patient education”, he said.

"My role is to give the patient to tools to recognise an allergy attack and how to act accordingly, how to stop it – letting the person know what they must avoid and how", said Dr Pedro, who has also been contributing to the national research on immunology. “We’ve recently launched a website ( where patients can easily identify food allergens present in packaged foods. No one wants to read thousands of labels to find safe foods.”

Pioneers on Algarve research

“In the Algarve we also have very good data on patient’s allergic profiles. Our databases show that house dust mites represent about half of all cases of respiratory allergies in the Algarve. The most common pollen allergies are to wild grasses, olive tree and Russian thistle. This greatly contrasts with allergic profiles seen in Northern Europe and even in other regions in Portugal. Allergy is a global phenomenon with many regional particularities”, he said.