Allergy Patch Testing
What is allergy testing?
Hundreds of ordinary substances can trigger allergic reactions. Allergy testing can help identify substances to which you may be allergic, which is often an important step in your treatment.
There are different types of allergies, and they are investigated and treated by different specialists. Skin prick testing is performed by Immunologists. Dr Maiolo does not do skin prick testing.
Allergy testing that we perform in our clinic are:
- A blood test (sIgE or RAST) allows us to screen for some allergens, such as foods, dander, pollens, latex and dust mite. Depending on the result, Dr Maiolo may refer you for skin prick testing. The blood test measures the amount of allergy-causing antibodies in your bloodstream. Your blood sample will be sent to a medical laboratory to extract serum immunoglobulin E (IgE) and assesses it for the presence of antibodies that fight specific allergens.
- A patch test is a specialised test for allergies caused by substances that contact the skin. A minimum of 60 sticky dots containing different substances are taped to your back and then removed at 48 hours. An interim reading is done at this time. Your final reading will be done on day 5.
Who should have allergy testing?
- Skin rashes that flare up after contact with particular substances. This can happen with products that have been used long-term, and the flares may be delayed by a few days.
- Skin rashes that have a strange pattern (like square edges).
- Allergy testing may be suggested by Dr Maiolo based on your history and examination.
How should I prepare for allergy testing?
- There are no specific things you need to do to prepare for the allergy test.
- If having patch testing, you may need to arrange time off work (if you have a physical or outdoor job) as you won’t be able to get hot and sweaty whilst the sticky dots and tapes are in place.
- Antihistamines can be continued, but oral prednisolone should be stopped.
What are the risks of allergy testing?
- Patch testing to a substance you are very allergic to can cause an itchy red blister on the corresponding patch. This is uncommon and can be treated with corticosteroid ointment.
- We do not perform patch testing if you think you may be pregnant.
