April 15, 2022

What causes an allergy?

According to research, environmental and genetic factors are the main culprits for an allergy, although not all of the factors that can trigger it are known. In most cases, the allergy is caused by an immune system reaction mediated by either a specific type of antibody, immunoglobulin E, or certain blood cells, mast cells, and basophils.  

People with a tendency to suffer from allergies are called atopic and usually have allergy symptoms after being exposed to someone: 

  • Food (food allergy).
  • Allergen present in the atmosphere (eg, pollen) and causes respiratory allergies (eg, allergic bronchial asthma, allergic conjunctivitis, allergic rhinitis, etc.).
  • Allergen in the atmosphere that causes skin allergies (eg, eczema).

Insect (eg, wasp or bee) that often manifests as a multisystem allergy. 

  • Medication, with the most “common suspects” being analgesics and antibiotics.

There are also so-called “weird” or “unexplained” allergies that do not fall into a category and do not show the usual allergy-like symptoms. Also, many people develop indoor allergies triggered by a humid and hot environment (eg, dust mites), as well as allergies to proteins present in pet skin cells (rather than their hair, as many believe). . 

Allergy symptoms 

An allergy can have a number of symptoms that differ in the area where they occur and their severity. Atopic allergies manifest with immediate symptoms after exposure to an allergen (eg, bronchospasm, rhinitis, eczema, itchy eyes or even vomiting or diarrhea), in most cases. But there are also allergies that start as a gastrointestinal problem or eczema and develop into asthma that can lead to airway obstruction and other respiratory symptoms. 

Factors that trigger an allergy 

In addition to the type of allergen, the age of the patient plays an important role in the onset of an allergy. In infancy, food allergies are much more common than in older adults, especially those triggered by milk and eggs. Usually, foods that cause allergies in infants become more tolerable by the body after the age of 3 years. At the same time, however, older people are often more prone to allergies to inhaled substances. 

Much depends on the body itself, however. Allergic rhinitis, for example, can appear as a benign condition in its early stages in some people (an annoyance during flowering). In others, it may not even be noticed until after several years of exposure to an allergen. 

Allergy diagnosis 

The patient’s history will be able to give the doctor a first idea of ​​where and when the patient is experiencing allergy symptoms. For this reason, the patient’s history is one of the most important tools in the hands of a doctor to diagnose the allergy that afflicts the individual. 

It is worth noting that some allergies are life-threatening (anaphylaxis or anaphylactic shock) and sudden, especially those that accompany an insect bite or the ingestion of certain medications or foods (allergic shock). That is why it is important for the doctor to investigate all the symptoms allergy presented by a patient and find their probable cause. Confirmation comes a little later and after some special tests, such as the quantification of IgE antibodies and skin tests. 

Although it is not always possible, it is important to try to understand your allergies so that you know what to avoid in order not to trigger them. Your doctor will help you reduce your exposure to the factors that cause your allergies and minimize the discomfort they cause you.