An allergy is an adverse reaction that the body has to a particular food or substance in the environment. Most substances that cause allergies are not harmful and have no effect on people who are not allergic.
The severity of allergies varies from person to person and can range from minor irritation to anaphylaxis — a potentially life-threatening emergency.
Red watering eyes
Runny nose, sneezing, obstruction, itching
Shortness of breath, wheezing
Food borne allergies:
Abdominal pain, bloating
Skin rashes, hives, angioedema
An allergy develops when the body’s immune system reacts to an allergen as though it is a threat, like an infection. It produces antibodies to fight off the allergen, in a reaction called the "immune response".
The next time a person comes into contact with the allergen, the body "remembers" the previous exposure and produces more of the antibodies. This causes the release of chemicals in the body that lead to an allergic reaction.
Food: shellfish, peanut, strawberries
Insect stings: bee, wasp
Drugs: penicillin, antiepileptics
Skin prick test, patch test
Blood: serum IgE level, RAST
Allergen challenge test
Avoid exposure to known allergens
Avoid such foods
Change of town for seasonal hay fever
Regular dusting of carpet, use of light furniture
Use of medical bracelet
Children are more prone
Recurrent sinusitis, pneumonia, ear infections
Antiallergics: Over the counter drugs like cetirizine fexofenadine can be used
Anaphylaxis: treated with epinephrine (epipens should be carried at all times)