Allergies: what they are and how to spot them

When we notice that we have an itchy throat, irritated eyes, a stuffy nose, etc., we usually put it down to temperature changes and assume that we have a cold, but what if we are confusing allergy symptoms with other conditions?

At Probelte Pharma, a laboratory that manufactures vaccines and allergy tests, we believe that getting a proper diagnosis of allergic sensitisation is the first step to helping patients enjoy a better quality of life. With this in mind, we manufacture various diagnostic tests, which help patients to avoid the allergen in question or to receive appropriate treatment.

WHAT IS AN ALLERGY?

It is an immune response by your body when foreign substances enter it, so it is simply your body’s defence mechanism to protect you against any substance that may enter your body through the respiratory or digestive tracts, or through your skin. When the body recognises these as foreign substances, it tries to neutralise them, either through tolerance mechanisms or by triggering an extreme immune response, which leads to what we call allergy symptoms.

TYPES OF ALLERGIES

Depending on the symptoms they produce and trigger, there are three different types of allergy, each of which are therefore diagnosed and treated differently:

RESPIRATORY ALLERGIES

Some people have a strong reaction when an external substance comes into contact with their respiratory system. This

typically includes coughing, sneezing, tickling in the nose, eye irritation with tearing, itching, rhinitis and sometimes even asthma and these are triggered by a reaction to allergens such as grasses, dust, pollen or dust mites, among others. It is the most common form of allergy across the world.

SKIN ALLERGIES

This includes allergies that are caused by contact with the skin or through the skin (bites), the most common reactions are hives, eczema of the skin and inflammation, due to allergens such as medicines, metals, especially nickel, foods such as peach or kiwi and insect bites.

FOOD ALLERGIES

Food allergy is an altered response by the immune system to ingestion, contact or inhalation of a food, a component/ingredient or even a trace of a food.

The substances that cause allergies are not the foods themselves, they are caused by some of the proteins that are part of their composition, which are called allergens.

At this point we must ask ourselves what the difference is between food allergy and food intolerance, which are commonly confused. As noted above, an allergy is an immune response by the body to a foreign substance, in this case the reaction to a food could be either digestive (intestinal pain, diarrhoea or vomiting) or of another type (redness/rashes on the skin or inflammation). Your body reacts to allergens by producing IgE antibodies.

However, where intolerances are concerned, two different situations may occur, with or without the involvement of the immune system. In the first case, your body will produce IgG antibodies instead of IgE and the visible reaction will not be as immediate as it is with allergies, and in the second case the intolerance will be due to a lack of the enzymes responsible for metabolising certain foods, thus making you intolerant to them.

 TYPES OF DIAGNOSTIC TESTS

The tests performed by the specialist are designed to identify the substance that is triggering the allergic response in the patient. The most commonly used methods for diagnosing the cause of the disease are as follows:

• • The prick test or immediate sensitivity test: this involves applying a drop of the allergen being tested to the skin to assess the allergic inflammatory response. The skin is lifted slightly without bleeding (a gentle prick) and a single test is usually performed for several allergens, with each sample drop about 2 cm apart. The results are known in around 20 minutes.

• • Patch test, epicutaneous test or delayed hypersensitivity test: this test is assessed after 48-72 hours and requires more than one visit to a medical specialist, as allergen-soaked discs or patches are applied to the back and the response is observed after this time.

• • Allergen-specific IgE test or RAST: these are special blood tests where they test for the IgE (antibodies involved in the allergic reaction) specific to the allergen suspected of causing the symptoms, based on the patient’s medical history.

• • Challenge tests: the patient is exposed to the selected allergens in a controlled manner, with the aim of reproducing the symptoms in the target organ (nose, eyes, bronchial tubes). They are used to diagnose allergies to medicines, foods and additives.
    In this case of challenge tests that use injections, a small dose of allergen is administered and the response it triggers is observed. These tests are often used to test tolerance/intolerance for food or drug allergies.

At Probelte Pharma we have a wealth of experience in manufacturing diagnostic allergy tests.

Don’t miss out on enjoying days out in nature, find out if you really have an allergy and learn how to avoid the symptoms or treat them.