Allergies are very common and it is estimated that up to 20-30% of us have some form of allergy to one or more substances (known as allergens) in varying amounts.  Patients present with different symptoms depending of what they are allergic to;

• Airborne allergens (such as pollen, dust, fur, dander, spores or mould) present as allergic rhinitis, asthma or allergic conjunctivitis
• Skin contact (such as chemical, detergents, rubber or nickel) present as eczema or dermatitis
• Food ingested (such as dairy products, nuts, shell fish, medicines, preservatives or food colouring) present as swollen lips and face, difficulty breathing, skin rash, diarrhoea or vomiting)

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Mechanism of Allergy

Patients with allergy have a hypersensitive immune mechanism that causes them to produce excessive amounts of IgE antibody following exposure to small amount of certain allergens.  These IgE antibody  causes mast cells to degranulate releasing histamine which then triggers an immediate inflammatory response resulting in the symptoms described above. 

Click to view MedXX video on Skin Patch Test

Allergy Tests Available

Your doctor may recommend an allergy test to help devise a treatment plan to help you manage your allergy symptoms safely and effectively

• A RAST or ELISA test is a blood test to look for IgE antibodies to specific allergens because when a person has allergies, the body produces IgE antibodies in larger quantities
• A Skin Allergy Prick Test looks for an allergic reaction of a person’s skin to different allergens introduced using a pin prick
• A Skin Allergy Patch Test looks for an allergic reaction of a person’s skin to different allergens introduced on a patch for 48 hours

Click to view Nemours video on Skin Prick Test

Differences between skin prick / patch and RAST blood test

	Skin Prick	Skin Patch	RAST blood test
Speed of Results	15 minutes	48 hours	Few days
Allergic reaction	Small risk	Small risk	No risk
Young children	Multiple pricks	Patches	Single pin prick

Discuss with your ENT, lung, skin or allergy specialist doctor about an allergy test if you have allergic symptoms

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If you think you may be suffering from any medical condition, you should seek immediate medical attention from your doctor or other professional healthcare providers. You should never delay seeking medical advice, disregard medical advice, or discontinue medical treatment because of information on this website.