Your Allergy Questions Answered: Causes, Symptoms, and Diagnosis

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What Are Allergies?

Allergies happen when your immune system reacts to substances that are usually harmless. These substances are called allergens and can cause various reactions in your body.

What Causes Allergies?

Allergies are triggered by an overreaction of your immune system to allergens. Common allergens include:

  • Pollen from trees, grass, and weeds (causing seasonal allergies)
  • Dust mites
  • Pet dander
  • Mold
  • Certain foods (like nuts, shellfish, and dairy)
  • Insect stings
  • Medications
  • Latex

What Are the Symptoms of Allergies?

Allergy symptoms depend on the allergen and how sensitive you are. Common symptoms include:

  • Sneezing
  • Runny or blocked nose
  • Itchy or watery eyes
  • Hives (itchy red spots on the skin)
  • Swelling of lips, tongue, eyes, or face
  • Coughing
  • Wheezing or difficulty breathing
  • Anaphylaxis (a severe, life-threatening reaction)

Symptoms of Seasonal Allergies

Seasonal allergies, also known as hay fever, occur during certain times of the year when plants release pollen. Symptoms include:

  • Sneezing
  • Runny or blocked nose
  • Itchy or watery eyes
  • Itchy throat or ears
  • Cough

Causes of Skin Allergies

Skin allergies are caused by direct contact with allergens. Common triggers include:

  • Certain metals (like nickel)
  • Scents and preservatives found in beauty and skincare products
  • Plant oils (such as poison ivy)
  • Latex

Causes of Food Allergies

Food allergies occur when the immune system reacts to specific proteins in foods. Common food allergens include:

  • Peanuts
  • Tree nuts (like almonds and walnuts)
  • Shellfish
  • Fish
  • Dairy products
  • Eggs
  • Wheat
  • Soy

How Are Allergies Diagnosed?

Diagnosing allergies involves looking at your medical history, doing a physical exam, and running specific tests. Common tests include:

  • Skin Prick Test: Small amounts of allergens are put into your skin to see if there's a reaction.
  • Blood Test: Measures antibodies (IgE) in your blood that react to allergens.
  • Elimination Diet: Identifying food allergies by removing suspected foods from your diet and then slowly adding them back while watching for symptoms.

Tests for Diagnosing Allergies

  • Skin Prick Test: Allergens are pricked into your skin to check for reactions.
  • Blood Test (RAST or ELISA): Looks for specific IgE antibodies in your blood.
  • Patch Test: Identifies contact dermatitis by applying patches with allergens to your skin for 48 hours.
  • Oral Food Challenge: Under medical supervision, you eat small amounts of a suspected allergen to see if there’s a reaction.

Allergy Causes and Treatment

Causes of Allergies

Allergies occur when your immune system reacts to certain substances known as allergens. This can be influenced by genetics, environment, and lifestyle.

Treatment for Allergies

  • Avoidance: The best way to manage allergies is to avoid the allergens that trigger them.
  • Medications: Antihistamines, decongestants, and corticosteroids can help relieve symptoms.
  • Immunotherapy: Allergy shots or tablets under the tongue can help your body get used to allergens.
  • Emergency Treatment: For severe allergies (anaphylaxis), having an epinephrine auto-injector (like an EpiPen) is crucial.

Frequently Asked Questions

Q: What actions should I take if I experience a severe allergic reaction?
A: Use an epinephrine auto-injector if you have one and seek emergency medical help immediately.

Q: Can allergies develop later in life?
A: Yes, you can develop allergies at any age, even if you’ve never had them before.

Q: What steps can I take to minimize my exposure to allergens?
A: Keep windows closed during high pollen seasons, use air purifiers, clean regularly to reduce dust, and avoid known food allergens.

Q: Are allergies hereditary?
A: Allergies can run in families, so if your parents have allergies, you might be more likely to have them too.


Understanding allergies, their causes, symptoms, and how they are diagnosed is key to managing them effectively. If you think you have allergies, it’s important to see a healthcare provider for proper testing and treatment. Managing allergies well can greatly improve your quality of life.