Allergies and Allergic Reactions

What are Allergies

An Allergy is a hypersensitivity to foreign substances which are normally harmless but which produce a violent reaction in the allergy sufferer. Your immune system’s job is to protect you from bacteria and viruses. If you have allergies, though, part of your immune system works too hard. It may attack harmless substances such as cat dander or pollen in your eyes, nose, lungs, and under your skin. When you come in contact with an allergen, your immune system starts to generate chemicals known as IgE antibodies. And these chemical compounds can motive histamine, which causes swelling, infection and a build up of mucous.

Allergies are generally the body's effort to eliminate something it considers unsuitable. Typical allergic reactions are hay fever, migraines, asthma, hay fever, digestive disturbances, coeliac disease, conjunctivitis, skin conditions such as urticaria and eczema, drowsiness, Chronic fatigue syndrome (CFS), hyperactivity in children, tinnitus, recurrent sinusitis and ear infections. In a few people the histamine (anaphylactic) reaction can cause muscle cramps, disorientation, unconsciousness and even death from shock or suffocation.

Allergy vs Intolerance

An Allergy is not the same as an intolerance. Allergies always involve the immune system, whereas an intolerance, eg. lactose intolerance, is caused by a lack of lactase, the enzyme that converts lactose into glucose.


Almost any substance can be an allergen for an individual. Common allergens include certain foods, especially milk, wheat and eggs, pollens, dust, moulds, cosmetica and certain food additives.

Type 1 Allergies

There are different types of Allergies, the most common being type 1. When an allergen encounters cells capable of antibody formation, they then form IgE antibodies which bind to the surface of other cells, called mast cells and basophils. In response to the attachment those cells release chemicals, called mediators of anaphylaxis, among them histamine. Those chemicals cause allergic reactions such as swelling or the secretion of mucus.