Allergy Patch 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 looks for immediate allergies (like hives and anaphylaxis). These often occur to foods, pollens and grasses, and animal dander. Skin prick testing is performed by Allergist/Immunologists and are not offered at myPRODERM.
- Patch testing looks for delayed or chronic allergies, which are insidious and can cause or aggravate eczema (dermatitis). These are usually chemicals that are in personal care products, cosmetics, medications, dyes or industrial products in the wortkplace. They may even be containted within a product that has been used long term, with no previous issues. Path testing is performed by Dermatologists and is offfered at myPRODERM.
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. The blood test measures the ammount of allergy-causing andibodies 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. Depending on the result, your Dermatologist may refer you for skin prick testing.
- 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.
- 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.
- 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.
- 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.