Patch testing is used to determine if a contact allergen is responsible for your eczema or dermatitis.
Eczema or dermatitis may occur on the skin in areas that have come into contact with an allergen. For example if you have applied sunscreen to the face and you are allergic to an ingredient within the sunscreen, you will develop a rash on the face after several applications or sooner if previously exposed to the allergen.
Patch testing performed by Dermatologists is used to detect delayed type 4 hypersensitivity reactions (eg eczema) and is different to prick testing performed by Immunologists, which detects immediate type 1 hypersensitivity reactions (eg urticaria, angioedema and anaphylaxis).
Perth Dermatology Clinic operates a Contact Allergy Patch Testing Clinic for further investigation of potential contact allergy/dermatitis. Patch tests are ordered specific to your individual requirement determined by your Dermatologist. Payment for patch testing is required in advance of your order and a Medicare rebate applies for this service. Please note that some medications need to be stopped prior to patch testing (eg oral prednisolone) so please inform your dermatologist of your medications.
Three appointments (Mon/Wed/Fri) will be made for your patch testing. Patch tests are applied to your back by our nursing staff on your first visit and must remain intact and dry for 48 hours (ie no sport which generates sweating or wetting of this area, as the tests will come off and render the test unreadable). After 48 hours you return for your second visit to the clinic and our nurse will perform the first reading, document any positive reactions, and draw on your back with a permanent marker. You can shower and exercise from this point on, so long as you re-mark the areas with permanent marker afterwards. Your final reading is after 96 hours with our nurse at your third appointment and at this stage you are then provided with your results. After this you may see your Dermatologist again to discuss the relevance of the results and avoidance of these allergens as appropriate.