Alergic reactions affects millions of people through out the entire world. The concept of allergies and alergic reactions was first introduced in 1906 by a Viennese pediatrician Clemons von Pirquet. He noted that some patients are hypersensitive to normally innocuous substances like dust, certain foods and pollen. The word ‘allergy’ is from the Greek words ‘aalos’ meaning ‘other’ and from ‘ergon’ meaning ‘work’. Through out the history of mankind, all forms of hypersensitivity were originally classified as allergies. They were all thought to originate through the improper activation of the immune system. It was later recognized that numerous different disease mechanisms were to blame, the common link being the immune system.

Philip Gell and Robin Coombs designed a new classification in 1963 that included the description of four types of hypersensitivity reactions, known as Type I to Type IV hypersensitivity. This new introduction meant that the word ‘allergy’ was reserved for only type 1 hypersensitivities. Also known as immediate hypersensitivity, they have been classified as rapidly developing reactions. This is where the term ‘alergic reactions’ came into being.

There is a multitude of reasons why the alergic reactions take place. Just as this is the case, there are also numerous different alergic reactions that can be realized from an allergen. Airborn dust or pollen particles are one of the most common forms that peole develop an alergic reaction from. The symptoms of these alergic reactions can be felt in any areas of the human body. They can affect the eyes, nose, mouth and lungs. Alergic rhinitis is also known as the common hay fever, causes irritations of the nose, sneezing and itching and redness of the eyes. Some allergens that are inhaled can also bring the onset of alergic reactions. These symptoms are noticed by the narrowing of the airways and increased production of mucus in the lungs. They can also include a shortness of breath, coughing and wheezing, similar to those who suffer from asthma.

Alergic reactions can also be the result of certain foods, insect and bee stings. They can show up after taking some forms of medication like antibiotics like penicillin and the common aspirin. These types of alergic reactions can include the swelling of the skin as with hives. Although alergic reactions to foods rarely cause respiratory reactions, but some can be life threatening. When an alergic reaction is noticed from taking medication, also called, anaphalaxis, a number of organs can be affected. These include the respiratory system, the circulatory system and the digestive system.

Depending on the rate of severity, some alergic reactions can cause cutaneous reactions, bronchoconstriction, edema, hypotension, coma, and even death. This type of reaction can be immediate, or it can take time to manifest itself. Epinephrine is sometimes needed when the alergic reactions become severe enough. This is taken in the form of a needle, commonly called an EpiPen or Twinject. When an anaphalxic alergic reaction is taking place, it can often seem like the reaction or symptoms are going away, but over a prolonged period of time they can resurface to cause further reactions.