A Guide to Allergies

What is an Allergy?

Allergy, derived from the Greek work 'allos', meaning 'other' and 'ergon' meaning 'reaction' or 'reactivity', an allergy or Type 1 hypersensitivity is an immune malfunction. The body reacts immunologically to nonimmunogenic substances known as 'allergens'. Type 1 hypersensitivity is characterized by excessive activation of mast celss by immunoglobulin E resulting in a systemic inflammatory response with common symptoms such as a runny nose to life threatening anaphylactic shock and even death.

History of 'Allergy'

A Viennese pediatrician by the name of Clemens von Pirquet first came up with the concept and terminology of an "allergy" in 1906 when he observed peculiar symptoms in some of his patients that he believed may have resulted in the body's response to outdoor allergens such as dust, pollen and certain foods.

Hypersensitivities for quite some time were though to stem from the improper action of inflammatory immunoglobulin (class lgE) however it soon became clear that several different mechanisms utilizing different effector molecules were responsible for the myriad of disorders previously classified as 'allergies'. A new four-class (now five) classification scheme was designed by P.G.H. Gell and R.R.A. Coombs and characterized by classical lgE mediation of effects; 'Allergy' has replaced the name 'Type 1 Hypersensitivity'.

The Signs & Symptoms of an Allergy

·(Allergic rhinitis) the swelling of the nasal mucosa.
·Habits such as 'nasal salut' or 'allergy salut' when a person wipes the nose upwards due to itching.
·(Allergic conjunctivitis) when the eyes are red or itchy.
·(bronchoconstriction) wheezing, dyspnoea or attacks of asthma.
·Skin rashes such as, hives, eczema or contact dermatitis.

Systemic allergic response, referred to as 'anaphylaxis', depending on the rate of severity can cause 'cutneous' reactions, bronchoconstriction, edema, hypotension, coma and sometimes even death.

Hay fever is one example of an exceedingly common minor allergy. Many suffer symptoms in response to airborne pollen. People referred to as 'asthmatics' are often allergic to dust mites and apart from 'allergens', allergic reactions can be due to medications as well.