what is Allergic Reaction?

1 ANSWERS

1. Guest6406
   

   An allergic reaction is the body's way of responding to an "invader." When the body senses a foreign substance, called an antigen, the immune system is triggered. The immune system normally protects the body from harmful agents such as bacteria and toxins. Its overreaction to a harmless substance (an allergen) is called a hypersensitivity reaction, or an allergic reaction.
   
   Anything can be an allergen. Dust, pollen, plants, medications, foods, insect venoms, animal dander, viruses, or bacteria are examples of allergens.
   
   
   Reactions may occur in one spot, such as a small localized skin rash, itchy eyes, or all over, as in a whole body rash such as hives (urticaria).
   
   
   A reaction may include one or several symptoms.
   Most allergic reactions are minor, such as a rash from poison ivy, mosquito bites, or sneezing from hay fever. The type of reaction depends on the person's immune system response, which is sometimes unpredictable.
   
   In rare cases, an allergic reaction can be life-threatening (known as anaphylaxis). Each year in the United States, it is estimated that up to 500-1,000 fatalities due to anaphylaxis occur each year and affects 1%-2% of the population as a whole.

   Report (0) (0)  |   12 years, 9 month(s) ago