Do you need a referral for patch testing?

Patch testing helps investigate delayed skin reactions, often when contact with a product or material is suspected. Small amounts of selected substances are placed on the skin under patches, then the sites are checked at planned follow-up visits. A clinician chooses the substances based on your rash pattern, work, hobbies, cosmetics, medicines, and everyday exposures. A referral can provide this background, but the testing service may also collect it during its own assessment.

Ask the dermatology service whether you need a referral and whether the appointment includes testing or only an initial review. Make a list of products that touch the affected skin, including soaps, fragrances, cosmetics, hair products, adhesives, topical medicines, and workplace materials. Photograph the rash when it is active and bring product names or ingredient lists if available. Ask the service which creams or medicines need to be paused and how to protect the patches during the testing period.

Seek urgent medical care for facial swelling, trouble breathing, faintness, rapidly spreading blistering, extensive skin peeling, or a rash involving the eyes or mouth. Contact the testing service if the test area becomes intensely painful, develops marked swelling, or appears infected. Do not remove patches early unless the treating team tells you to do so.

Ask: What type of reaction are we investigating? Which products should I bring or avoid? How many review visits are planned? How will a positive result change my skin-care routine? What should I do if the rash worsens while testing is underway?