Other names: Allergic reaction


Allergies occur when your immune system reacts to a foreign substance — such as pollen, bee venom, or pet dander — that doesn't cause a reaction in most people. Your immune system produces substances known as antibodies that identify a particular allergen as harmful. When you come into contact with the allergen, your immune system's reaction can inflame your skin, sinuses, airways, or digestive system.


Allergy symptoms depend on the substance involved and can range from mild irritation to severe reactions like anaphylaxis. Symptoms can affect the airways, sinuses, nasal passages, skin, and digestive system.

Hay fever may cause:

Food allergies may cause:

Insect sting allergies may cause:

Drug allergies may cause:

Atopic Dermatitis, also called eczema, may cause skin to:


Anaphylaxis Some allergies can trigger a severe reaction known as anaphylaxis. Signs include loss of consciousness, drop in blood pressure, severe shortness of breath, skin rash, lightheadedness, rapid weak pulse, nausea, and vomiting.


For severe allergic reactions (anaphylaxis), seek emergency medical help immediately. If you have had severe allergy attacks in the past or signs of anaphylaxis, make an appointment with an allergy specialist.


Allergies start when your immune system mistakes harmless substances for dangerous invaders. Common triggers include airborne allergens like pollen and animal dander, certain foods like peanuts and shellfish, insect stings like bee venom, medications like penicillin, and substances you touch like latex.


Risk factors for developing allergies include a family history of asthma or allergies, being a child (more likely to develop allergies), and having asthma or other allergic conditions.


Complications of allergies can include anaphylaxis (severe allergic reaction), asthma, atopic dermatitis (eczema), sinusitis, ear infections, lung infections, and fungal complications in the sinuses or lungs.


Before seeing your doctor for allergy symptoms:


Questions to ask your doctor: 1. What is causing my symptoms? 2. Do I need allergy tests? 3. Should I see an allergy specialist? 4. What is the best treatment? 5. How can I manage other health conditions with my allergies? 6. What changes can I make at home to reduce symptoms? 7. When should I seek medical help? 8. What are emergency symptoms my family should know? 9. Are there generic alternatives to prescribed medicines? 10. Can you recommend any resources for more information?


Tests for allergies may include detailed questions about symptoms, physical exams, keeping symptom diaries, skin tests exposing you to allergens pricking the skin and blood tests measuring specific antibodies.


Allergy treatments involve allergen avoidance if possible and medications to reduce symptoms. Immunotherapy may be recommended for severe cases not relieved by other treatments.


Preventing allergic reactions involves avoiding triggers where possible and keeping a diary to track symptoms. Consider wearing a medical alert bracelet if you have had severe reactions in the past.


  1. What are allergies?

Allergies occur when your immune system reacts to foreign substances that are usually harmless.

  1. What are common allergy symptoms?

Symptoms can affect the airways (sneezing), skin (itching), digestive system (swelling), and more depending on the allergen.

  1. What is anaphylaxis?

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

  1. How should one prepare for a doctor's appointment regarding allergies?

Prepare by noting down symptoms, family history of allergies/asthma, current medications and asking relevant questions about diagnosis and treatment options.

  1. What are common causes of allergies?

Common causes include airborne allergens (pollen), certain foods (peanuts), insect stings (bee venom), medications (penicillin), and substances you touch (latex).

  1. Who is at increased risk of developing allergies?

Those with a family history of asthma/allergies or individuals with existing allergic conditions like asthma are at higher risk.

  1. What are some complications of allergies?

Complications can include anaphylaxis, asthma exacerbation triggered by allergens exposure (allergy-induced asthma), atopic dermatitis (eczema), sinusitis among others.

  1. How are allergies diagnosed?

Diagnosis involves detailed questioning about symptoms along with physical exams; tests like skin prick tests or blood tests may also be conducted.

  1. What are common treatments for allergies?

Treatments include allergen avoidance strategies where possible; medications such as antihistamines; immunotherapy for severe cases; emergency epinephrine shots for anaphylaxis.

  1. How can one prevent allergic reactions at home?

Preventive measures include avoiding known triggers like pollen or dust mites; keeping symptom diaries; wearing a medical alert bracelet if necessary for severe reactions.