What causes allergies?

Allergy is one of the most common immune pathologies today. It already affects more than 30% of the population against only 3% in the 1960s!

Allergy is a type of immune system response to a foreign substance that is usually harmless to most people. These substances, known as allergens, can be found in various sources, such as food, pollen, animal dander, insect stings, and certain medications.

Wrongly trivialized, allergy is an inappropriate reaction of the immune system against these allergens (also recognized as multiple antigens in regards to the immune system), even in minimal quantities. 

In normal individuals, these same allergens cause no reaction.

Symptoms of allergies

The allergic reaction can cause various symptoms, depending on the type and severity of the allergy.

Some common symptoms of allergy include:

• Sneezing
• Runny or stuffy nose
• Itchy or watery eyes
• Rashes or hives
• Swelling
• Shortness of breath or wheezing
• Abdominal pain, diarrhea, or vomiting (in the case of food allergies)

Type of allergies

There are several types of allergies, classified based on the allergen that triggers the immune response. 

Food allergies

People can be allergic to a wide variety of foods. Here are some of the most common food allergens:

• • Peanuts: this is one of the most common food allergens
  • Tree nuts: this includes nuts such as almonds, cashews, walnuts, and pecans
  • Shellfish: this includes shrimp, crab, lobster, and other types of shellfish.
  • Fish: some people are allergic to certain types of fish, such as salmon or tuna.
  • Milk: this is a common allergen, especially in children.
  • Eggs: some people are allergic to the proteins found in eggs.
  • Wheat: this is commonly found in foods such as bread, pasta, and cereal.
  • Sesame: this is a growing allergen, with more people being diagnosed in recent years.
  • Gluten: this has also grown rapidly over the last years.

Seasonal allergies

Also known as hay fever or allergic rhinitis, those are allergic reactions to airborne allergens such as pollen from trees, grasses, and weeds. These allergens are most prevalent during the spring, summer, and fall seasons.

Animal allergies

These are triggered by animal dander, urine, or saliva, commonly from cats and dogs, but also from other animals like birds and rodents.

Animal allergies can be particularly problematic for people who live with pets, as they are constantly exposed to allergens. However, even people who do not own pets may experience allergic reactions when visiting homes with pets or public spaces with animal exposure.

Insect sting allergies

These are reactions to the venom injected into the body by insects such as:

• Bees
• Wasps
• Hornets
• Yellowjackets
• Fire ants
• Biting flies
• Certain types of caterpillars

These insects inject venom through their stingers or other body parts when they perceive a threat or are disturbed. 

For most people, stings from these insects cause only minor pain and swelling, but for some individuals, they can trigger severe allergic reactions. It’s important to note that not all stinging insects produce venom that can cause an allergic reaction, and the severity of the reaction can vary from person to person.

Medication allergies

We can be allergic to a wide range of medications, including:

• Antibiotics such as penicillin, sulfa drugs, and cephalosporins
• Nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin, ibuprofen, and naproxen
• Chemotherapy drugs
• Anticonvulsant medications
• Anesthetics such as lidocaine and Novocain
• Insulin and other diabetes medications
• Radiographic contrast agents used in imaging tests

Latex allergies

This is a specific reaction to products made from natural rubber latex. Natural rubber latex comes from the sap of the rubber tree and is used to make a variety of products, including:

• Medical gloves
• Condoms
• Balloons
• Rubber bands
• Adhesives
• Carpet backing
• Rubber toys
• Wetsuits and other water sports gear

Contact allergies

Also known as contact dermatitis, contact allergies are a type of skin allergy that occurs when the skin comes into contact with a substance that it is allergic to. This can include a wide range of substances, such as:

• Metals (nickel, cobalt, chromium, gold, silver, etc.)
• Fragrances (limonene, linalool, citronellol, etc.)
• Preservatives and other chemicals (parabens, benzalkonium chloride, formaldehyde)

It’s important to note that out of all these different types of allergies, someone can have multiple allergies, for example, food allergies and seasonal allergies.