Health: A-Z Health Glossary - A is for 'Allergies'
An allergy is an excessively exaggerated immune response or reaction to a substance that is generally not harmful to most people.
Allergic reactions can vary from a mild one to the very severe. Interestingly, some children grow out of their allergies, while others do not.
People with allergies are often sensitive to more than one substance. The most common substances that often cause allergic reactions are:
* Food
* Insect stings
* Dust mites
* Pollen
* Medicines
* Mould spores
* Pet dander
* Jewellery
* Chemicals
* Plants
* Cosmetics
Allergies are quite common in the general populace. Some people experience allergies so severe that they are life threatening and require medical intervention in order not to expire. (Photo right: Example of allergy to dust/mites)
Anaphylaxis is a severe allergic reaction, which if left untreated could mean the person may die (adrenaline is usually the first line of treatment). Both genetics and environmental factors play a role in whether or not a person will get allergies at any time in their life.
Some medical conditions such as eczema and asthma, are linked to allergies.
Allergies can cause the following symptoms:
* runny nose
* sneezing
* itching
* rashes
* swelling
* asthma (this is a more serious allergic reaction)
The part of the body that is in contact with the allergen is what has an impact on the symptoms that develop.
* Food allergies can cause nausea, vomiting, diarrhoea, abdominal pain, cramps
* Allergens that are breathed in, can cause a blocked and itchy nose, itchy throat, excessive mucus, coughing and even wheezing
* Drug allergies often affect most of the body and can have a whole variety of symptoms
* Allergies to plants and cosmetics, often cause a skin rash on the site of application
Symptoms of allergies vary among person to person in their severity. Even at their worst, allergies generally will not kill you, although they will make you feel quite bad. The exception is experiencing anaphylaxis (a really rare and extreme allergic reaction) which is very much life-threatening.