Skin Prick Tests

Sue Ferguson Allergy Technician does the allergy tests (skin prick tests).  She is the Skin Prick Test Allergy Technician trained by Dr Rodney Ford.  She interprets but does not manage the results.  You can take the results to your health professional for ongoing advice.  The skin prick tests only detect allergy.  They do not detect a food intolerance (such as gluten and dairy intolerance).

Sue will be leaving for overseas from 13 August and the clinic will be closed permanently.

Consultations – Please book on-line using “appointments” tab

Skin Prick test. How does it work?

The skin-prick test measures immediate reactions.  It is a test that measures the “IgE-sensitivity” to the allergens which have been pricked gently into the skin.  As soon as the allergen gets into the skin, it comes in contact with the allergy cells in your skin (the mast cells, which are packed full of histamine).

If your mast cells have been sensitized to that allergen, they will immediately release their histamine, and this creates the wheal, just like a mosquito bite.

The skin-prick test is a biological reaction and takes about 10–15 minutes to get to its maximum intensity.

If the child has been treated with an antihistamine within the preceding 24 hours, then the skin tests will be attenuated. In other words reactions, will be less dramatic and will take longer to show up.

Skin-prick tests can accurately identify food allergens

Who should get tested?

We recommend that all babies, all children and all adults with eczema or asthma should be tested with a selection of skin-test allergens.  All breastfed babies with eczema need skin-prick testing.  All people who have troublesome allergy symptoms should be investigated by skin-prick tests. Consequently, we recommend skin-prick testing for all children with eczema.

Skin-prick tests can be done at any age: even on new-born babies (although it is less reliable at this age).  It is our routine practice to do the first set of skin-prick tests at about four months of age.  By this age the baby has developed the capacity to mount a specific IgE-response in the skin.  But, if the baby has bad eczema in the first few weeks of life, then it is useful to do the skin tests earlier.

This is especially helpful in breastfed babies with eczema.  Most of the time these babies are reacting to food proteins that are coming through in their mother’s breast milk.  By accurately identifying what the baby’s skin is reacting to in the breast milk, we can then advise the mother about what foods that she should be avoiding in her diet.  Usually, the eczema will completely go away.

What allergens can be tested?

There are two categories of allergens that you can be tested for: food and inhalants.

Foods: The most common and useful foods to test for are:

cow’s milk
egg white
tree nuts

In adults, testing for shellfish is important. Usually, food reactions to fruits and vegetables cannot be successfully tested by skin tests – that is because these fruit and vegetables reactions are usually caused by the chemicals in these foods, rather than by the food proteins.

Inhalants: The important inhalant allergens (also called aero-allergens) are:

house dust mite
grass pollens (rye grass, timothy grass)
tree pollens (especially birch)
animal dander (cat fur, dog hair, horse hair, and feathers).