Your Dermatologist will advise you about further investigations required and a management plan.
Allergy Patch Tests are carried out to determine if the dermatitis or skin rashes could bedue to an allergy to a particular substance that your skin is contacting.
The patch testing process involves applying a special adhesive tape to the back which contains diluted concentrations of a number of common allergens.
Patch tests are not the same as skin prick allergy tests (SPT). The SPT is more useful for food allergy and dust mite allergy etc.
At South East Dermatology Stafford we use the Australian standard baseline series of 60 allergens. This is based on a 10 year retrospective review of the commonest presentations to a busy Australian Allergy clinic1
Patch tests series using less allergens are often used elsewhere eg Standard European Series and True Test. The True test series for example has up to 36 allergens. These limited series will miss a significant number of potential allergens compared to the Australian series.
Your dermatologist may also customise further allergy testing based on your history of exposure and occupation.
The allergy patch tests are usually applied on Monday, removed on Wednesday and read on Thursday or Friday. The reason this patch test requires three visits is that it takes 96 hours for skin to react to a particular substance after that substance has been applied. Occasionally this reaction may occur within the first day, however a positive result is usually not seen until 48 hours.
reference – Toholka R, Wang YS, Tate B, Tam M, Cahill J, Palmer A, Nixon R. The first Australian Baseline Series: Recommendations for patch testing in suspected contact dermatitis. Australas J Dermatol. 2015 May; 56 (2):107-15. doi: 10.1111/ajd.12186.