An allergy refers to an exaggerated reaction by our immune system in response to bodily contact with a foreign substance. Allergy-producing substances are called "allergens" Examples of allergens include pollen, dust mite, mould, danders and food.
Common allergic conditions include hay fever, asthma, allergic eczema, hives, allergic eyes and allergic rhinitis.
An undetected allergy or intolerance can lead to a later cross reaction to other foods, however, in many instances difficulties arise in pinpointing the food allergens involved in causing allergy symptoms. Allergic conditions can be diagnosed in various ways, such as skin or blood tests and will help to identify the foods or substances that induce allergic responses or symptoms.
Skin Prick Test involves placing separate drops of solutions of allergen extracts onto the skin of your forearm or back and then using a very fine lancet to prick through the drop into the skin. A positive test results in a small raised wheal with a red surrounding flare. Results are known within fifteen minutes and the test is painless. It may be necessary for you to stop certain medications such as anti-histamine medications before a skin prick test. Oral or inhaled steroids do not interface with skin prick test.
Patch testing is well established method for detecting allergies to substances which come into direct contact with the skin. This reaction is known as allergic contact dermatitis and is a form of 'delayed' allergy because the reaction takes two to three days to develop. It is of value for the investigation of any persistent eczema and, in particular, where there is clinical suspicion of contact allergy.
