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Published on July 21, 2023Published on October 27th, 2023
A picture showing how allergies cause a person to sneeze with watery eyes

Common allergies symptoms you might experience.

What is the definition of allergies?

Allergies occur when the immune system, which is responsible for defending the body, reacts excessively. This happens because immune cells mistakenly identify harmless substances, known as allergens, as harmful invaders like bacteria or viruses. Allergens can include things like pollen, pet dander, and nuts. When the immune system misidentifies these allergens, it triggers an allergic reaction in the body.

The most common types of allergies include:

  • Indoor and outdoor allergies: These involve allergens such as plant pollens, mold spores, dust mites, and pet dander.
  • Skin allergies: These can be caused by substances like poison ivy and oak, certain foods, and latex.
  • Food allergies: Common food allergens include milk, soy, eggs, wheat, peanuts, tree nuts, fish, and shellfish.
  • Drug allergies: This type of allergy often involves reactions to penicillin antibiotics.
  • Insect allergies: Allergic reactions can occur due to bee and wasp stings, bites from venomous ants, as well as exposure to cockroaches and dust mites.

What causes allergies?

In order to develop an allergy, it is necessary for an individual to be sensitized to the substance they are allergic to. This means their body must have been exposed to the specific allergen, leading the immune system to mistakenly perceive it as a threat and create memory antibodies against it. The exact reasons why this happens are not fully understood by experts.

While allergies can affect anyone, they are more likely to occur if a person has a genetic predisposition to allergies, also known as atopy. Here are some facts regarding the chances of inheriting allergies:

  • If both parents do not have allergies, there is approximately a 15% risk of the child developing allergies.
  • If one parent has allergies, the risk increases and can reach up to 50% for the child.
  • If both parents have allergies, the risk of the child developing allergies can be as high as 80%.

It’s important to note that allergies are not caused by factors such as E-numbers (food additives), genetically modified foods, fast food, or immunizations.

What are the main symptoms of allergies?

Allergic reactions can manifest in a range of symptoms, varying from mild to severe, with the most severe being anaphylaxis, a life-threatening condition. These symptoms typically affect the specific part of the body that encounters the allergen, although this is not always the case.

Common symptoms of allergies include:

  • Sneezing, congestion, and an itchy or runny nose (referred to as allergic rhinitis).
  • Wheezing, tightness in the chest, difficulty breathing, and coughing (associated with asthma).
  • Itchy, red, and watery eyes (known as allergic conjunctivitis)
  • Stomach pain, nausea, vomiting, and diarrhea
  • Dry, red, and cracked skin (eczema)
  • Red and itchy skin rash (dermatitis)
  • Raised and itchy areas on the skin (hives)
  • Swelling of the lips, tongue, eyes, or face (angioedema)

How to diagnose allergies?

Many individuals with mild allergies can manage their symptoms by using over-the-counter medications and avoiding triggers. However, if these measures are ineffective, seeking assistance from an allergy specialist for testing and treatment may be necessary.

In order for allergy testing to be meaningful, there should be a clear connection between a trigger and the resulting symptoms. This means that you notice symptoms occurring after being exposed to a specific trigger. An allergy specialist can perform an allergen challenge test by gently pricking the skin with small amounts of the suspected allergen (as well as related allergens) to observe if a reaction occurs.

If there are no distinct symptoms present, allergy testing typically cannot provide a reliable diagnosis. Conducting allergy tests without a clear history of allergic reactions can lead to misleading outcomes.

Once your allergy has been confirmed, you will have a better understanding of what you should avoid. If complete avoidance of the trigger is not feasible, the allergy specialist can suggest suitable treatments to effectively manage your symptoms.

See all medications related to Allergies

Which medications are used for allergies?

Allergy medicationscan be categorized into three main types: antihistamines, corticosteroids, and decongestants. These medications can be applied topically at the site of the allergic reaction or taken orally.

Topical treatments encompass various forms including;

  • Eye drops
  • Inhalers
  • Nasal sprays
  • Skin creams, lotions, or ointments.

Antihistamines work by blocking the effects of histamine, a substance that triggers symptoms like itching, runny nose, and sneezing during an allergic reaction. They can be used to prevent allergy symptoms if taken before exposure to the allergen, as well as to alleviate symptoms if taken afterward.

Examples of antihistamines include:

  • Diphenhydramine (Benadryl)
  • Loratadine (Claritin)
  • Cetirizine (Zyrtec)
  • Fexofenadine (Allegra)

Corticosteroids are potent anti-inflammatory medications that are effective for short-term treatment of symptoms such as irritation, redness, swelling, itching, or pain.

They come in different forms, including;

  • Prednisone (Deltasone) – Oral tablets
  • Budesonide (Rhinocort) – Nasal sprays
  • Hydrocortisone (Cortizone, Pandel) – Creams

Decongestants help relieve nasal congestion by reducing the swelling of blood vessels in the nose. They can be taken alone, such as pseudoephedrine (Sudafed), or in combination with antihistamines, like loratadine/pseudoephedrine (Claritin-D).

It’s important to note that anaphylaxis, a severe allergic reaction, is a medical emergency and requires different treatment approaches.


What are allergies?

Allergies occur when the immune system reacts excessively to substances known as allergens, treating them as harmful invaders. These allergens can include pollen, pet dander, foods, drugs, and insect stings.

What are the most common types of allergies?

The most common types are indoor and outdoor allergies, skin allergies, food allergies, drug allergies, and insect allergies.

How do allergies develop?

While the exact cause remains unknown, an individual becomes sensitized to a substance they are allergic to upon exposure. Genetic predisposition, known as atopy, can also increase the likelihood of developing allergies.

What symptoms can one experience due to allergies?

Common symptoms include sneezing, nasal congestion, itchy/runny nose, wheezing, difficulty breathing, itchy/red eyes, stomach pain, skin rash, and swelling in parts of the face.

How are allergies diagnosed?

If there’s a clear connection between a suspected trigger and symptoms, an allergy specialist can perform an allergen challenge test by pricking the skin with the allergen. A positive reaction indicates an allergy.

What medications are commonly used for allergies?

Allergy medications include antihistamines (e.g., Benadryl, Claritin, Zyrtec, Allegra), corticosteroids (e.g., Deltasone, Rhinocort, Cortizone), and decongestants (e.g., Sudafed, Claritin-D).

How can one prevent allergic reactions?

Avoiding known allergens is the best prevention. If complete avoidance is not possible, managing the symptoms with appropriate medications, as suggested by an allergy specialist, can help.

Is it true that allergies can be inherited?

Yes, genetics play a role in the development of allergies. If both parents have allergies, a child’s risk of developing allergies can be as high as 80%.

Can allergies be caused by food additives or genetically modified foods?

No, allergies are not caused by factors such as E-numbers (food additives), genetically modified foods, fast food, or immunizations.

What is anaphylaxis?

Anaphylaxis is a severe and life-threatening allergic reaction that requires immediate medical attention.

Are over-the-counter medications effective for allergies?

Many individuals with mild allergies can manage their symptoms using over-the-counter medications. However, if symptoms persist, it’s advisable to see an allergy specialist for tailored treatments.

Can allergies be cured?

While there’s no cure for allergies, they can be managed effectively with the right diagnosis, avoidance strategies, and medications.