Skin Prick Testing
Involves placing test substances (commercially available allergens) on the skin of the forearm that are then pricked into the skin using a sterile lancet. This is not a painful technique and is easily performed on both children and adults. The tests are read after 15 minutes. Positive tests will be revealed by a small red raised wheal on the arm where the allergen was placed.
Prick to Prick Testing
For food allergy testing to a wide variety of foods such as nuts, fish, shellfish, meat, fruits, wheat and yeast is available. Individuals with allergic problems to less common foods and complex sauces can be tested by a technique called “prick to prick testing”, where the actual potential food allergen is lightly pricked into the skin.
Preparations of inhalant allergens such as grass and tree pollens, cats, dogs, house dust mites and fungal spores are available for testing rhinitis/conjunctivitis (hay fever) sufferers.
Those who react adversely to insect stings such as bee and wasp venom can also be investigated using this technique.
The significant advantage of allergy skin prick testing is that the results are available during the consultation. However blood tests for allergy – specific IgE testing (RASTs), can be undertaken to clarify certain allergic issues. These blood tests can allow component resolved diagnosis (the precise molecular allergen) when desensitisation is being considered.