Allergies come to the surface when the internal system that is responsible for shielding the body reacts to an outside substance. This foreign body can be anything like dust, pollen, pet dander etc. Not to forget even food products act as a foreign substance for your body and can be a cause for allergies. 

The internal system that is responsible for shielding the body against foreign bodies is termed as the immune system. The immune system produces substances known as ANTIBODIES that identifies allergens as harmful or acceptable. When you come into contact with the allergen, your immune system's reaction can inflame your skin, sinuses, airways or digestive system. The severity of allergies varies from person to person and can range from minor irritation to anaphylaxis — potentially life-threatening emergency.


Allergy symptoms, which depend on the substance involved, can affect your airways, sinuses and nasal passages, skin, and digestive system. Allergic reactions can range from mild to severe. In some severe cases, allergies can trigger a life-threatening reaction known as anaphylaxis.

A food allergy can cause:

  •   Tingling in the mouth    
  •   Swelling of the lips, tongue, face or throat  
  •   Hives   
  •   Anaphylaxis 

An insect sting allergy can cause: 

  •   A large area of swelling (edema) at the sting site 
  •   Itching or hives all over the body            
  •   Cough, chest tightness, wheezing or shortness of breath     
  •   Anaphylaxis

A drug allergy can cause: 

  •   Hives           
  •   Itchy skin  
  •   Rash       
  •   Facial swelling       
  •   Wheezing          
  •   Anaphylaxis

Atopic dermatitis, an allergic skin condition also called eczema, can cause the skin to:

  •   Itch    
  •   Redden     
  •   Flake or peel

Hay fever, also called allergic rhinitis, can cause:

  •   Sneezing       
  •   Itching of the nose, eyes or roof of the mouth    
  •   Runny, stuffy nose      
  •   Watery, red or swollen eyes (conjunctivitis