Allergic reactions can be mild or severe. They occur often as a response of the body's immune system as it tries to fight something strange in the body. The strange substances commonly known as allergens can either be harmful or harmless. Some people are more sensitive to a given type of allergen as compared to others, and this explains why some allergies are mild while others are life-threatening.

   There are many allergic reactions, and it can be difficult to identify the potential of an allergy unless you've experienced one before.Allergen That said, there are some common food allergies, drug allergies, and food intolerance cases. Go on reading to better understand different types of allergies.

   Types of allergic reactions

   Allergies are classified according to the cause, how severe they are and the probable treatment options. The first and most common is the type I hypersensitivity. It is characterized by an immediate reaction that occurs mainly as a result of certain foods, drugs, insect stings and exposure to pollen materials.

   Type II hypersensitivity involves certain antibodies in the body. The most affected antibodies are the Immunoglobin G; lgM and IgG. These complex protein molecules cause binding and may destroy the cells in which they are bound. This type of allergic reaction is most common as a result of organ transplants where the body refuses to identify the transplanted organ as one of its own.

   Type III hypersensitivity is an immune-complex allergic reaction. When it occurs, it can lead to a series of reactions which may even destroy some tissues in the body.

   Type IV hypersensitivity - this one takes some time to show up and habitually involves the T-cells lymphocytes. It takes hours or even days for the T-cells to initiate an allergic response. An example of such is contact dermatitis, which can occur due to contact with certain substances.

   Common allergic disorders

   Under the type I hypersensitivity, there are various allergic disorders common in many people across the globe. Insect bites for example - wasps, ants, bees, hornets or yellow jacket - can cause mild to serious reactions depending on an individual's immune system and genetic background.

   Allergic asthma caused by inhaled allergens such as fungal spores, dust, pollen or molds falls under the type I hypersensitivity as well. Thickening of the mucous membrane, shortness of breath, severe wheezing or cough is some of the common symptoms. Antihistamine drugs are usually prescribed to reduce the effects of the reaction.

   The difference between allergic reaction and food intolerance is that the latter takes some time for the symptoms to show up while when it comes to allergic reactions, the symptoms show up almost instantly.